Lab 1 Osmosis And Diffusion Essay 1992 Answers To Math

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2 AP Biology Lab Review

3 AP Biology Lab 1: Diffusion & Osmosis  Description  dialysis tubing filled with starch- glucose solution in beaker filled with KI solution  potato cores in sucrose solutions  determining solute concentration of different solutions

4 AP Biology Lab 1: Diffusion & Osmosis  Concepts  semi-permeable membrane  diffusion  osmosis  solutions  hypotonic  hypertonic  isotonic  water potential

5 AP Biology Lab 1: Diffusion & Osmosis  Conclusions  water moves from high concentration of water (hypotonic=low solute) to low concentration of water (hypertonic=high solute)  solute concentration & size of molecule affect movement through semi-permeable membrane

6 AP Biology Lab 1: Diffusion & Osmosis ESSAY 1992 A laboratory assistant prepared solutions of 0.8 M, 0.6 M, 0.4 M, and 0.2 M sucrose, but forgot to label them. After realizing the error, the assistant randomly labeled the flasks containing these four unknown solutions as flask A, flask B, flask C, and flask D. Design an experiment, based on the principles of diffusion and osmosis, that the assistant could use to determine which of the flasks contains each of the four unknown solutions. Include in your answer: a.a description of how you would set up and perform the experiment; b.the results you would expect from your experiment; and explanation of those results based on the principles involved. Be sure to clearly state the principles addressed in your discussion.

7 AP Biology Lab 2: Enzyme Catalysis  Description  measured factors affecting enzyme activity  H 2 O 2  H 2 O + O 2  measured rate of O 2 production catalase

8 AP Biology Lab 2: Enzyme Catalysis  Concepts  substrate  enzyme  enzyme structure  product  denaturation of protein  experimental design  rate of reactivity  reaction with enzyme vs. reaction without enzyme  optimum pH or temperature  test at various pH or temperature values

9 AP Biology Lab 2: Enzyme Catalysis  Conclusions  enzyme reaction rate is affected by:  pH  temperature  substrate concentration  enzyme concentration calculate rate?

10 AP Biology ESSAY 2000 The effects of pH and temperature were studied for an enzyme-catalyzed reaction. The following results were obtained. a. How do (1) temperature and (2) pH affect the activity of this enzyme? In your answer, include a discussion of the relationship between the structure and the function of this enzyme, as well as a discussion of ho structure and function of enzymes are affected by temperature and pH. b. Describe a controlled experiment that could have produced the data shown for either temperature or pH. Be sure to state the hypothesis that was tested here. Lab 2: Enzyme Catalysis

11 AP Biology Lab 3: Mitosis & Meiosis  Description  cell stages of mitosis  exam slide of onion root tip  count number of cells in each stage to determine relative time spent in each stage  stages of & crossing over in meiosis  model cell stages & crossing over  farther genes are from each other the greater number of crossovers

12 AP Biology Lab 3: Mitosis & Meiosis  Concepts  mitosis  interphase  prophase  metaphase  anaphase  telophase  meiosis  meiosis 1  separate homologous pairs  meiosis 2  separate sister chromatids  crossing over  in prophase 1 I PMAT

13 AP Biology Lab 3: Mitosis & Meiosis  Conclusions  Mitosis  cell division  growth, repair  making clones  longest phase = interphase  each subsequent phase is shorter in duration  Meiosis  reduction division  making gametes  increasing variation  crossing over in Prophase 1

14 AP Biology Lab 3: Mitosis & Meiosis ESSAY 1987 Discuss the process of cell division in animals. Include a description of mitosis and cytokinesis, and of the other phases of the cell cycle. Do not include meiosis. ESSAY 2004 Meiosis reduces chromosome number and rearranges genetic information. a. Explain how the reduction and rearrangement are accomplished in meiosis. b. Several human disorders occur as a result of defects in the meiotic process. Identify ONE such chromosomal abnormality; what effects does it have on the phenotype of people with the disorder? Describe how this abnormality could result from a defect in meiosis. c. Production of offspring by parthenogenesis or cloning bypasses the typical meiotic process. Describe either parthenogenesis or cloning and compare the genomes of the offspring with those of the parents.

15 AP Biology Lab 4: Photosynthesis  Description  determine rate of photosynthesis under different conditions  light vs. dark  boiled vs. unboiled chloroplasts  chloroplasts vs. no chloroplasts  use DPIP in place of NADP +  DPIP ox = blue  DPIP red = clear  measure light transmittance  paper chromatography to separate plant pigments

16 AP Biology Lab 4: Photosynthesis  Concepts  photosynthesis  Photosystem 1  NADPH  chlorophylls & other plant pigments  chlorophyll a  chlorophyll b  xanthophylls  carotenoids  experimental design  control vs. experimental

17 AP Biology Lab 4: Photosynthesis  Conclusions  Pigments  pigments move at different rates based on solubility in solvent  Photosynthesis  light & unboiled chloroplasts produced highest rate of photosynthesis Which is the control?#2 (DPIP + chloroplasts + light)

18 AP Biology Lab 4: Photosynthesis ESSAY 2004 (part 1) A controlled experiment was conducted to analyze the effects of darkness and boiling on the photosynthetic rate of incubated chloroplast suspensions. The dye reduction technique was used. Each chloroplast suspension was mixed with DPIP, an electron acceptor that changes from blue to clear when it is reduced. Each sample was placed individually in a spectrophotometer and the percent transmittance was recorded. The three samples used were prepared as follows. Sample 1 —chloroplast suspension + DPIP Sample 2 —chloroplast suspension surrounded by foil wrap to provide a dark environment + DPIP Sample 3 —chloroplast suspension that has been boiled + DPIP Data are given in the table on the next page. a.Construct and label a graph showing the results for the three samples. b.Identify and explain the control or controls for this experiment. c.The differences in the curves of the graphed data indicate that there were differences in the number of electrons produced in the three samples during the experiment. Discuss how electrons are generated in photosynthesis and why the three samples gave different transmittance results.

19 AP Biology Lab 4: Photosynthesis ESSAY 2004 (part 2) Time (min) Light, Unboiled % transmittance Sample 1 Dark, Unboiled % transmittance Sample 2 Light, Boiled % transmittance Sample 3 028.829.228.8 548.730.129.2 1057.831.229.4 1562.532.428.7 2066.731.828.5

20 AP Biology Lab 5: Cellular Respiration  Description  using respirometer to measure rate of O 2 production by pea seeds  non-germinating peas  germinating peas  effect of temperature  control for changes in pressure & temperature in room

21 AP Biology Lab 5: Cellular Respiration  Concepts  respiration  experimental design  control vs. experimental  function of KOH  function of vial with only glass beads

22 AP Biology Lab 5: Cellular Respiration  Conclusions   temp =  respiration   germination =  respiration calculate rate?

23 AP Biology Lab 5: Cellular Respiration ESSAY 1990 The results below are measurements of cumulative oxygen consumption by germinating and dry seeds. Gas volume measurements were corrected for changes in temperature and pressure. a. Plot the results for the germinating seeds at 22°C and 10°C. b. Calculate the rate of oxygen consumption for the germinating seeds at 22°C, using the time interval between 10 and 20 minutes. c. Account for the differences in oxygen consumption observed between: 1. germinating seeds at 22°C and at 10°C 2. germinating seeds and dry seeds. d. Describe the essential features of an experimental apparatus that could be used to measure oxygen consumption by a small organism. Explain why each of these features is necessary. Cumulative Oxygen Consumed (mL) Time (minutes)010203040 Germinating seeds 22°C0.08.816.023.732.0 Dry Seeds (non-germinating) 22°C0. Germinating Seeds 10°C0. Dry Seeds (non-germinating) 10°C0.0

24 AP Biology Lab 6: Molecular Biology  Description  Transformation  insert foreign gene in bacteria by using engineered plasmid  also insert ampicillin resistant gene on same plasmid as selectable marker  Gel electrophoresis  cut DNA with restriction enzyme  fragments separate on gel based on size

25 AP Biology Lab 6: Molecular Biology  Concepts  transformation  plasmid  selectable marker  ampicillin resistance  restriction enzyme  gel electrophoresis  DNA is negatively charged  smaller fragments travel faster

26 AP Biology Lab 6: Transformation  Conclusions  can insert foreign DNA using vector  ampicillin becomes selecting agent  no transformation = no growth on amp + plate

27 AP Biology Lab 6: Gel Electrophoresis  Conclusions DNA = negatively charged smaller fragments travel faster & therefore farther correlate distance to size

28 AP Biology Lab 6: Molecular Biology ESSAY 1995 The diagram below shows a segment of DNA with a total length of 4,900 base pairs. The arrows indicate reaction sites for two restriction enzymes (enzyme X and enzyme Y). a.Explain how the principles of gel electrophoresis allow for the separation of DNA fragments b.Describe the results you would expect from electrophoretic separation of fragments from the following treatments of the DNA segment above. Assume that the digestion occurred under appropriate conditions and went to completion. I.DNA digested with only enzyme X II.DNA digested with only enzyme Y III.DNA digested with enzyme X and enzyme Y combined IV.Undigested DNA c.Explain both of the following: 1.The mechanism of action of restriction enzymes 2.The different results you would expect if a mutation occurred at the recognition site for enzyme Y.

29 AP Biology Lab 6: Molecular Biology ESSAY 2002 The human genome illustrates both continuity and change. a.Describe the essential features of two of the procedures/techniques below. For each of the procedures/techniques you describe, explain how its application contributes to understanding genetics.  The use of a bacterial plasmid to clone and sequence a human gene  Polymerase chain reaction (PCR)  Restriction fragment polymorphism (RFLP analysis) b.All humans are nearly identical genetically in coding sequences and have many proteins that are identical in structure and function. Nevertheless, each human has a unique DNA fingerprint. Explain this apparent contradiction.

30 AP Biology Lab 7: Genetics (Fly Lab)  Description  given fly of unknown genotype use crosses to determine mode of inheritance of trait

31 AP Biology Lab 7: Genetics (Fly Lab)  Concepts  phenotype vs. genotype  dominant vs. recessive  P, F1, F2 generations  sex-linked  monohybrid cross  dihybrid cross  test cross  chi square

32 AP Biology Lab 7: Genetics (Fly Lab) ESSAY 2003 (part 1) In fruit flies, the phenotype for eye color is determined by a certain locus. E indicates the dominant allele and e indicates the recessive allele. The cross between a male wild type fruit fly and a female white eyed fruit fly produced the following offspring The wild-type and white-eyed individuals from the F1 generation were then crossed to produce the following offspring. a. Determine the genotypes of the original parents (P generation) and explain your reasoning. You may use Punnett squares to enhance your description, but the results from the Punnett squares must be discussed in your answer. b. Use a Chi-squared test on the F2 generation data to analyze your prediction of the parental genotypes. Show all your work and explain the importance of your final answer. c. The brown-eyed female of the F1 generation resulted from a mutational change. Explain what a mutation is, and discuss two types of mutations that might have produced the brown-eyed female in the F1 generation. Wild-Type Male Wild-Type Female White-eyed Male White-Eyed Female Brown-Eyed Female F-1 0455501 Wild-Type Male Wild-Type Female White-eyed Male White-Eyed Female Brown-Eyed Female F-2 233122240

33 AP Biology Lab 7: Genetics (Fly Lab) ESSAY 2003 (part 2) The formula for Chi-squared is: Probability (p) Degrees of Freedom (df) 12345.053.845.997.829.4911.1 22 =  (observed – expected) 2 expected

34 AP Biology Lab 8: Population Genetics  Description  simulations were used to study effects of different parameters on frequency of alleles in a population  selection  heterozygous advantage  genetic drift

35 AP Biology Lab 8: Population Genetics  Concepts  Hardy-Weinberg equilibrium  p + q = 1  p 2 + 2pq + q 2 = 1  required conditions  large population  random mating  no mutations  no natural selection  no migration  gene pool  heterozygous advantage  genetic drift  founder effect  bottleneck

36 AP Biology Lab 8: Population Genetics  Conclusions  recessive alleles remain hidden in the pool of heterozygotes  even lethal recessive alleles are not completely removed from population  know how to solve H-W problems!  to calculate allele frequencies, use p + q = 1  to calculate genotype frequencies or how many individuals, use, p 2 + 2pq + q 2 = 1

37 AP Biology Lab 8: Population Genetics ESSAY 1989 Do the following with reference to the Hardy-Weinberg model. a. Indicate the conditions under which allele frequencies (p and q) remain constant from one generation to the next. b. Calculate, showing all work, the frequencies of the alleles and frequencies of the genotypes in a population of 100,000 rabbits of which 25,000 are white and 75,000 are agouti. (In rabbits the white color is due to a recessive allele, w, and agouti is due to a dominant allele, W.) c. If the homozygous dominant condition were to become lethal, what would happen to the allelic and genotypic frequencies in the rabbit population after two generations?

38 AP Biology Lab 9: Transpiration  Description  test the effects of environmental factors on rate of transpiration  temperature  humidity  air flow (wind)  light intensity

39 AP Biology Lab 9: Transpiration  Concepts  transpiration  stomates  guard cells  xylem  adhesion  cohesion  H bonding

40 AP Biology Lab 9: Transpiration  Conclusions   transpiration   wind   light   transpiration   humidity

41 AP Biology Lab 9: Transpiration ESSAY 1991 A group of students designed an experiment to measure transpiration rates in a particular species of herbaceous plant. Plants were divided into four groups and were exposed to the following conditions. Group I:Room conditions (light, low humidity, 20°C, little air movement.) Group II:Room conditions with increased humidity. Group III:Room conditions with increased air movement (fan) Group IV:Room conditions with additional light The cumulative water loss due to transpiration of water from each plant was measured at 10-minute intervals for 30 minutes. Water loss was expressed as milliliters of water per square centimeter of leaf surface area. The data for all plants in Group I (room conditions) were averaged. The average cumulative water loss by the plants in Group I is presented in the table below. 1.Construct and label a graph using the data for Group I. Using the same set of axes, draw and label three additional lines representing the results that you would predict for Groups II, III, and IV. 2.Explain how biological and physical processes are responsible for the difference between each of your predictions and the data for Group I. 3.Explain how the concept of water potential is used to account for the movement of water from the plant stem to the atmosphere during transpiration. Average Cumulative Water Loss by the Plants in Group I Time (minutes)Average Cumulative Water Loss (mL H 2 O/cm 2 ) 103.5 x 10 -4 207.7 x 10 -4 3010.6 x 10 -4

42 AP Biology Lab 10: Circulatory Physiology  Description  study factors that affect heart rate  body position  level of activity  determine whether an organism is an endotherm or an ectotherm by measuring change in pulse rate as temperature changes  Daphnia

43 AP Biology Lab 10: Circulatory Physiology  Concepts  thermoregulation  endotherm  ectotherm  Q 10  measures increase in metabolic activity resulting from increase in body temperature  Daphnia can adjust their temperature to the environment, as temperature in environment increases, their body temperature also increases which increases their heart rate

44 AP Biology Lab 10: Circulatory Physiology  Conclusions  Activity increase heart rate  in a fit individual pulse & blood pressure are lower & will return more quickly to resting condition after exercise than in a less fit individual  Pulse rate changes in an ectotherm as external temperature changes

45 AP Biology Lab 10: Circulatory Physiology ESSAY 2002 In mammals, heart rate during periods of exercise is linked to the intensity of exercise. a.Discuss the interactions of the respiratory, circulatory, and nervous systems during exercise. b.Design a controlled experiment to determine the relationship between intensity of exercise and heart rate. c.On the axes provided below, indicate results you expect for both the control and the experimental groups for the controlled experiment you described in part B. Remember to label the axes.

46 AP Biology Lab 11: Animal Behavior  Description  set up an experiment to study behavior in an organism  Betta fish agonistic behavior  Drosophila mating behavior  pillbug kinesis

47 AP Biology Lab 11: Animal Behavior  Concepts  innate vs. learned behavior  experimental design  control vs. experimental  hypothesis  choice chamber  temperature  humidity  light intensity  salinity  other factors

48 AP Biology Lab 11: Animal Behavior  Hypothesis development  Poor: I think pillbugs will move toward the wet side of a choice chamber.  Better: If pillbugs prefer a moist environment, then when they are randomly placed on both sides of a wet/dry choice chamber and allowed to move about freely for 10 minutes, most will be found on the wet side.

49 AP Biology Lab 11: Animal Behavior ESSAY 1997 A scientist working with Bursatella leachii, a sea slug that lives in an intertidal habitat in the coastal waters of Puerto Rico, gathered the following information about the distribution of the sea slugs within a ten-meter square plot over a 10- day period. a.For the data above, provide information on each of the following:  Summarize the pattern.  Identify three physiological or environmental variables that could cause the slugs to vary their distance from each other.  Explain how each variable could bring about the observed pattern of distribution. b.Choose one of the variables that you identified and design a controlled experiment to test your hypothetical explanation. Describe results that would support or refute your hypothesis. time of day12 mid4am8am12 noon4pm8pm12 mid average distance between individuals 8.08.944.8174.0350.560.58.0


University students often struggle to understand the role of water in plant cells. In particular, osmosis and plasmolysis appear to be challenging topics. This study attempted to identify student difficulties (including misconceptions) concerning osmosis and plasmolysis and examined to what extent the difficulties could be revised during a plant physiology course. A questionnaire was developed to monitor university students’ conceptual knowledge before and after a course, and both qualitative and quantitative data were obtained. The data were analyzed using the constant comparison technique and descriptive statistics. Students were found to come to university with many misconceptions that had accumulated during their education. These misconceptions are extremely difficult to change during the traditional course, which comprises lectures and practical exercises. Students’ misconceptions originate from commonly used sources such as textbooks, which are perceived as being reliable. Effective teaching of water relations in plant cells could include such didactic methods as “questioning the author,” which allow teachers to monitor students’ knowledge and help students acquire a more scientific understanding of key concepts.


Misconceptions and Conceptual Change: General Concept

According to the constructivist view of learning, preconceptions play a crucial and productive role in the acquisition of expertise. Students’ prior notions serve as a resource for cognitive growth within a complex system of knowledge (Smith et al., 1994). Over the past three decades, students’ misconceptions in a wide range of subject areas have been identified and categorized (e.g., see Pfundt and Duit, 2004). These personal conceptions are often deeply rooted and instruction-resistant obstacles to the acquisition of scientific concepts, and they may remain even after instruction (Dikmenli, 2010). It is well documented that such misconceptions are resistant to change (e.g., Driver 1989; Mintzes et al., 1998, 2005). Misunderstandings may have been present before any teaching and can be found even after teaching has taken place (Özmen, 2004). It has also been reported that such misconceptions may be held by teachers or presented in textbooks (Wandersee et al., 1994; Bahar, 2003; Dikmenli, 2010).

The process of changing misconceptions to correct scientific conceptions is called conceptual change. Chi and Roscoe (2002) proposed that misconceptions should be named as “miscategorization of concepts” and the process of conceptual change as “conceptual reorganization,” since it needs an ontological shift from one “ontological category” to another. They point out that this reorganization is difficult or challenging when students are unaware of their misconceptions and/or lack the alternative category into which they should reassign them. However, diagnosing students’ conceptions and misconceptions is a prerequisite to developing lessons that result in a conceptual change (Odom, 1995).

The Issue of Water Relations in Plant Cells

Water relations in plant cells are among the most important topics in university courses on plant physiology. Learning about mechanisms underlying water balance in plant cells is dependent on understanding concepts such as osmosis and diffusion. Diffusion is defined as the random, thermal movement of molecules in which a net flow of matter moves along a concentration gradient (from an area of higher concentration toward an area of lower concentration; Friedler et al., 1987; Freedman and Sperelakis, 2012). Osmosis is the flow of a solvent across a semipermeable membrane from a region of lower to higher solute concentration (Kramer and Myers, 2012). The osmotic flow is governed by water potential, which in a simplified form may be described as the sum of pressure potential and solute potential, wherein pressure potential is equal to hydrostatic pressure (Kramer and Myers, 2013). The water uptake and release in the cell is based on osmosis. Although the water transport through the cell membranes also occurs directly across the phospholipid bilayer, rapid translocation of large water volumes is carried out by aquaporins—major membrane intrinsic proteins, called also “water channels” (Johansson et al., 2000). In walled cells, osmotic flow of water out of the cell leads to a phenomenon called “plasmolysis,” in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall (Minorsky, 2008).

Misconceptions around Water Relations in Plant Cells

Our observations, based on our experience of teaching university students over many years, suggest that understanding mechanisms underlying the water relations in plant cells remains extremely difficult. These difficulties may result from the fact that this topic is related to the processes of diffusion and osmosis, which have been reported as some of the hardest biological concepts to understand (Odom, 1995; Sanger et al., 2001; She, 2004). It is thought that problems with understanding diffusion and osmosis are the result of a number of causes: a confusion regarding vernacular and scientific usage of such terms as pressure, concentration, and quantity; misunderstanding technical concepts such as solution, semipermeability, and molecular and net movement; and insufficient abilities in terms of formal reasoning, visualization, and thinking at the molecular level (Odom and Barrow, 1995; She, 2004).

These difficulties can result in students’ knowledge concerning diffusion and osmosis being fragmentary and burdened with a number of misconceptions. Inadequate appreciation of the random molecular movement concept results in a common belief that diffusion and osmosis occur because molecules “want” or “aim” to reach equal concentrations in the whole system (Friedler et al., 1987; Odom and Kelly, 2001; Meir et al., 2005). Other widespread misconceptions include 1) a conviction that the movement of particles takes place only until concentrations between environments equalize (Odom and Kelly, 2001; Meir et al., 2005; Tomažicˇ and Vidic, 2012) and 2) a view that diffusion speed is irrespective of the concentration difference (Meir et al., 2005).

Many students also have problems comparing concentrations and understanding the “equal concentration” term, which students often equate with meaning an equal quantity of water molecules on each side of the semipermeable membrane. There are also beliefs that increased molecular density is unrelated to pressure or volume; a view that solutes differing in the size of particles would have differing effects on osmosis; a conviction that both processes will not continue after the cell’s death; and, finally, a confusion between the concepts of diffusion and osmosis (Meir et al., 2005; Tomažiˇc and Vidic, 2012).

To understand basic mechanisms determining water balance in plant cells, it is necessary not only to understand diffusion and osmosis accurately but also to know about plasmolysis and be aware of the relationships between all three processes. Despite the fact that educational difficulties in understanding water relations may, to a large extent, be connected with problems arising from misunderstanding diffusion and osmosis, other factors disturbing the didactic process cannot be excluded.

Content Analysis and Textbooks as the Sources of Misconceptions

Some of the most important sources of students’ scientific knowledge are textbooks, which are often the major source of reference in biology lessons (Edling, 2006). Content analysis reports indicate that textbooks can contain serious factual errors (Cho et al., 1985; Dikmenli and Cardak, 2004; Kose and Hasenekoglu, 2011).

Content analysis is a useful research tool widely applied in the social sciences “for making valid and replicable interferences from data to their context” (Krippendorff, 1989). To investigate data within a specific content, the method requires a common analytical procedure, including formulating research questions, selecting samples, defining applied categories, outlining and implementing the coding process, and analyzing the results (Kaid, 1989; Krippendorff, 1989). According to Hsieh and Shannon (2005), the success of content analysis depends greatly on the coding. Therefore, coding was the last step in our research and addressed the question “Are textbooks a source of misconceptions about osmosis for Polish university students?”

The Aims of the Study

The first aim of our study was to identify and determine the prevalence of university biology students’ misconceptions concerning osmosis and plasmolysis. Next, we investigated whether and to what extent those misconceptions are subject to conceptual change in the course of discussing osmosis and plasmolysis during a plant physiology course. The prevalence of some misconceptions, a subset of which are more common than the scientific point of view among students, had prompted us to suspect that that they have their roots in commonly available and seemingly reliable sources of knowledge. Research indicates that the major source of reference for students during biology lessons is textbooks (Edling, 2006), which have already been shown to perpetuate some misconceptions (Cho et al., 1985; Dikmenli and Cardak, 2004; Kose and Hasenekoglu, 2011). Previous research prompted us to analyze whether high school and university textbook definitions of osmosis and plasmolysis contribute to the dissemination and preservation of the misconceptions concerning these phenomena.


Questionnaire Design

We developed a questionnaire to identify problems related to understanding the regulation of water balance in plant cells. The questions were based on previously gathered data obtained from informal interviews with biology high school and university teachers, class observations, student tests and examinations from previous years, and previous research (e.g., She, 2004; Meir et al., 2005; Tomažicˇ and Vidic, 2012). The data allowed us to identify areas that caused particular difficulties for students. Having identified a number of “difficult” topics and concepts, we designed a pilot version of the questionnaire that included open, semiopen and closed questions. The open questions were generally applied to obtain in-depth, qualitative data concerning student understanding of osmosis and plasmolysis. The closed and semiopen questions were applied to obtain quantitative data about the stage of education at which the concepts had been taught and the educational methods that had been used to introduce students to them.

The content validity of the questionnaire was established by two experienced biology academics. Next, the pilot study was completed by 32 biology students at Adam Mickiewicz University, and the initial version of the questionnaire was revised. For example, some of the open questions were clarified by changing them to semiopen or closed items.

The final version of questionnaire consisted of 12 questions (or tasks), of which four were closed, two semiopen, and the other six open (see questionnaire in the Supplemental Material). Four of the questions identified the education level at which students became familiar with the concepts of diffusion, osmosis, and plasmolysis and the didactic methods used to teach them. The remaining eight questions concerned students’ knowledge of definitions of diffusion, osmosis, plasmolysis, and water potential; their ability to use tonicity and water potential concepts as “forces” that determine net water flow in a certain direction; their ability to distinguish between osmosis and diffusion; their understanding of the relationship between osmosis and plasmolysis and the role of aquaporins in both processes; and, finally, their awareness of the nature of osmosis (physical) and plasmolysis (biological).

Students were asked to label their questionnaires with the numbers of their student groups and the last four digits of their personal identity numbers according to the scheme G (group number) and PIN last four numbers (e.g., 5355). Additionally, at the beginning of each respondent’s codes, we added the research stage number (S1 or S2).


All the participants were students enrolled in the plant physiology course in 2014. The research was carried out in two stages. First, the diagnostic questionnaire was completed by a group of 105 second-year biology students before starting a course on plant physiology comprising lectures and practical exercises in the field of water relations in plant cells (stage 1). Second, the same group of students answered the diagnostic questionnaire after the teaching sequence (stage 2). The size of the participant group at this stage was 98.

Structure of Plant Physiology Course

The whole plant physiology course comprised 30 hours of lectures, 10 hours of seminars, and 60 hours of practical exercises. The concepts of diffusion, osmosis, and plasmolysis were discussed directly during a lecture and 9 hours of practical exercises (two sessions of 4.5 hours each). During every practical exercise, students in groups of four performed four or five experiments. For each experiment, the students were obliged to write a report containing their results and conclusions. The conclusions were discussed with the teacher and, if necessary, corrected. One week after the practical exercises, the diagnostic questionnaire for stage 2 was completed.

Questionnaire Analysis

The questionnaire analysis method was based on Creswell (1994). First, the data were organized and prepared for analysis. We then read through all the questionnaires and letter-coded the data; the letter-coded data were used to develop categories (for details, see answer key in the Supplemental Material). The data were interpreted and described on the basis of the created categories. We applied the constant comparison technique when coding the data (Glaser and Strauss, 1967). In this process, codes and categories were repeatedly refined.

Questionnaires in which respondents indicated they were not familiar with a given concept (tasks 1 and 7) were excluded from the analysis. To ensure interrater reliability, two university biology teachers participated in the process of creating the coding system, and they independently analyzed the questionnaires. The initial coding agreement rate was 92%, and any disagreements were settled by discussion. Analysis of the incidence of each category allowed an indication of the most common misconceptions. Tasks with no or illegible answers were excluded from the analysis. For the analysis of the closed questionnaire questions, a descriptive statistic method was applied. The chi-square test (Stangroom, 2014a) was applied to determine the relationship between the frequency of incorrect answers to particular questions at different stages of the research (1 or 2; Huck, 2008). To investigate the significance of changed answers to the same questions and misconceptions, we applied the z-test for two-population proportions with the use of z-test calculator for two-population proportions (Bluman, 2009; Stangroom, 2014b). Tasks with illegible answers were excluded from the analysis.

Qualitative Analysis of Textbooks

We used content analysis to identify textbook definitions of osmosis and plasmolysis that may promote misconceptions. This method was also used to determine whether and how aquaporins are described. The analysis was performed with regard to 13 of the most commonly used textbooks in Poland (five at the high school level and eight at the university level). Literature-based categories were then set (e.g., Meir et al., 2005; Rundgren et al., 2010; Kramer and Myers, 2012) and used in the analysis. The following categories of osmosis definitions emerged: 1) not mentioning the presence of the semipermeable membrane; 2) indicating that particles pass through the biological membrane; 3) limiting the osmotic process to water molecules or liquids only; 4) indicating that osmosis is a case of diffusion; and 5) indicating tonicity or solute concentration gradient as the driving force for osmosis. The definition of plasmolysis provided by the textbooks was also analyzed using two criteria: 1) Is the definition of plasmolysis present in the given textbook or not? 2) Does the definition or description of the process indicate that plasmolysis results from osmotic flow of water from the cell? The analysis of the aquaporin definition was conducted in four categories: 1) indication that aquaporins participate in water transport; 2) indication that aquaporins are present in the cell membrane; 3) indication that aquaporins are proteins; and 4) indication that aquaporins form channels.


Stage 1: Students’ Knowledge and Understanding of Concepts Related to Water Balance in Plant Cells before the Plant Physiology Course

All participants stated that they were familiar with osmosis, and the vast majority claimed they had learned about it at an earlier (nonuniversity) stage of education (questionnaire, task 1). Most students (90%, n = 105) also claimed they were familiar with plasmolysis. The vast majority of students who claimed to be familiar with plasmolysis reported that the subject had been introduced at previous (nonuniversity) stages of education (90%; questionnaire, task 7). Respondents reported that their school classes concerning osmosis and plasmolysis had been mainly theoretical. Among other didactic methods used at school, students mentioned experiments illustrating osmosis (19%) or plasmolysis (19%) and a film or animation presenting osmosis (20%) or plasmolysis (6%; questionnaire, tasks 2 and 8).

Despite the fact that all students stated they were familiar with osmosis, only 11% of them were able to define the process correctly as permeation of water/solute/dispersed phase through the semipermeable membrane (Table 1, task 3). The most frequent mistakes included not mentioning the presence of the semipermeable membrane (66%), for example, “osmosis is penetration of the solution from higher concentration to lower concentration” (Student S1G2.2280), and confusion concerning kinds of particles passing through the membrane (57%), for example, “salts or other compounds dissolved in water migrate from the points of higher concentration to a place of lower concentration through the barrier” (Student S1G4.2806). Another widespread misconception (54%) was the belief that osmosis was a biological process that occurred only in cells of living organisms, that is, animal cells, plant cells, or both, but not in artificial systems (Table 2). This misconception appeared even if the student was able to define the osmotic process (Table 3, task 3/9a).


The significance of changes in percentage of correct answers before (stage 1) and after (stage 2) plant physiology course according the z-test for two-population proportions


The identified misconceptions and significance of changes in their distribution before (stage 1) and after (stage 2) plant physiology course


The relationship between the frequency of incorrect answers between the two different questions in the same stage of research

The vast majority of students were unable to indicate the difference between diffusion and osmosis. Only 7% explained that osmosis occurred in the presence of the semipermeable membrane, while in answers related to the process of diffusion, the membrane was usually absent (Table 1, task 5). Knowledge of the difference between diffusion and osmosis and the ability to define osmosis also varied (Table 3, task 3/5). The most widespread misconception concerning the difference between both processes was the belief that osmosis referred only to water (27%) and diffusion to other molecules or only to gases. The difference between both processes was often related to the concentration gradient, for example, “diffusion takes place down the concentration gradient, and osmosis not” (Student S1G3.3546), or the involvement of carriers, for example, “diffusion can be facilitated” (Student S1G2.6425; Table 2).

None of the students was able to give the correct definition of water potential (Table 1, task 6); however, 25% of them could indicate correctly the direction of the net movement of water molecules between solutions with differing water potentials (Table 1, task 4b). The most frequent mistake (25%) was to confuse the type of particles moving through the membrane, for example, both water and solutes. Another frequent (14%) error concerned an incorrect direction of net water flow (Table 2). Students were generally familiar with the concept of tonicity, since a third of them correctly identified the direction of net water flow when concepts of “hypertonic” and “hypotonic” solutions were applied (Table 1, task 4a). The direction of net water flow in this context was incorrectly indicated by only 9% of the students, and as in the case of water potential, the most frequent mistakes related to the kind of molecules passing through the membrane (25%).

More than half of the respondents (54%) correctly identified the plant cell as an example of a structure in which plasmolysis could be observed (Table 1, task 9a). The majority of students (60%) were also familiar with the concept of aquaporins and their function in the cell membrane (Table 1, task 11). However, only 16% could define plasmolysis accurately as being caused by osmotic water flow from the cell (Table 1, task 12). Among the most frequent incorrect answers concerning associations between both processes were statements about migration (transport) of water (10%), for example, “both processes are related to water transport” (student: S1.G1.5355), and operating principle (6%), for example, “both processes are energy independent” (student: S1.G3.6320; Table 2).

According to the chi-square test analysis, being able to define osmosis correctly and being able to identify the relationship between osmosis and plasmolysis were independent. Similarly, we did not observe any association between the ability to indicate structures where osmosis or plasmolysis occurred and the ability to correctly identify the relationship between osmosis and plasmolysis (Table 3, task 9a/12 and 9b/12). Only 30% of the participants were able to accurately describe the behavior of a cell placed in solutions that had higher or lower water potential than the water potential of the cell itself (Table 1, task 10; Figure 1A). Being able to illustrate cells in solutions differing in water potential, such as changes in cell shape, and knowledge of associations between osmosis and plasmolysis were dependent. The most frequent mistake was to confuse the direction of the net motion of water molecules (65%; Figure 1C), which, according to the chi-square test analysis, resulted from a lack of ability to apply the water potential concept in practice (Table 3, task 4b/10). The majority of the students (60%) did not include any changes in the cell shape in their drawings (Figure 1B). The awareness of the changes in the cell shape and the ability to indicate differences between osmosis and plasmolysis were independent (Table 3, task 10/12A). The average number of correct answers to the questionnaire items during the first stage of the research was 27%.


Examples of students’ drawings in response to task 10. (A) An example of proper answer (Student S1G3.7515). Direction of water molecules net flow is indicated correctly and changes in the cell shape were taken into account. (B) An example of answer...

Stage 2: Students’ Knowledge and Understanding of Concepts Related to Water Balance in Plant Cells after the Plant Physiology Course

After the plant physiology course, the average number of correct answers increased from 27 to 42%. Although the result was statistically significant (z‑score: 2.2863, p value is 0.02202, p < 0.05), it was still unsatisfactory, since it indicated that the topic of water relations in plants remained elusive for the majority of students even after lectures and practical activities. The largest increase in correct answers (from 25% in stage 1 to 54% in stage 2) concerned the direction of water flow between solutions differing in water potential (Table 1, task 4b). This gain is understandable, because water relations in plant cells were discussed during the course in the context of water potential, not tonicity. The knowledge of the “water potential” definition also increased significantly (Table 1, task 6), even though the term still remained rather obscure for students, with only 7% able to define it correctly as the amount of Gibb’s free energy (or useful work) that 1 mole of water contributed to the system. Osmosis was also much better understood (an increase from 11% correct in stage 1 to 32% in stage 2; Table 1, task 3). Generally, students were considerably less confused after the course about the type of particles passing through the membrane and were more aware of the participation of the semipermeable membrane in osmosis (Table 2). Although the number of correct osmosis definitions was much higher, almost two-thirds (68%) of respondents were still unable to give the correct answer.

The occurrence of misconceptions concerning the definition of osmosis remained unchanged. Students perceived it as a biological process (41%) and indicated that it occurs in living cells but not in artificial systems (Table 2). Their knowledge of the definition of osmosis and their ability to indicate structures where osmosis may be observed remained unrelated (Table 3, task 3/9a). A significant increase was observed in the percentage of correct answers about the difference between diffusion and osmosis (Table 1, task 5). Students’ prior belief that the difference was related to the concentration gradient disappeared (Table 2). However, answers linking the difference between both phenomena with the carriers’ involvement remained at the same level (Table 2). We did not observe any statistically significant changes in the occurrence of the misconception that osmosis was related only to water and diffusion to other molecules/gases (Table 2). As in stage 1, the ability to distinguish between diffusion and osmosis depended on being able to correctly define osmosis (Table 3, task 3/5).

An awareness of structures where plasmolysis may occur remained at the same level (Table 1, task 9b). We observed, however, a significant increase (from 30% in stage 1 to 50% in stage 2) in the proportion of correct illustrations of the cell placed in solutions in which the water potential differed in relation to the water potential of the cell (Table 1, task 10). Students were significantly less confused about the direction of water flow between solutions (Table 2). This reduction in confusion was probably due to the ability to use the water potential concept in practice and higher awareness of changes in the cell shape that occurred during water flow from the cell (Table 2). Interestingly, the relationship between the ability to apply the water potential concept in practice and the ability to identify accurate illustrations of events occurring in the cell placed in solutions with different water potentials that were apparent before the physiology course was not visible in stage 2 (Table 3, task 4b/10).

Students’ awareness of the association between plasmolysis and osmotic water flow outside the cell increased from 16% in stage 1 to 32% in stage 2, and the increase was statistically significant (Table 1, task 12). Nevertheless, most common misconceptions concerning this issue remained unchanged. Students still thought that osmosis and plasmolysis were related to water flow or that both processes had a common goal, that is, to reach equal concentrations (Table 2). Unlike in stage 1, students’ understanding of the relationship between osmosis and plasmolysis relied on being able to correctly define osmosis (Table 3, task 3/12). As in stage 1, the ability to identify the link between osmosis and plasmolysis did not result in the correct illustration of events occurring in the cell placed in solutions with different water potentials (Table 3, task 10/12) or in the awareness of changes in the shape of the cell placed in solutions of different water potentials (Table 3, task 10/12A). Also as in stage 1, we did not observe any relationship between the ability to indicate structures where osmosis or plasmolysis occurred and the ability to indicate the relationship between osmosis and plasmolysis (Table 3, tasks 9a/12 and 9b/12). The frequency of correct answers concerning the role of the aquaporin in plant cells remained unchanged (Table 2).

Qualitative Analysis of Textbooks

The high school and university textbooks were analyzed in terms of statements that supported the misconceptions identified above. Because students often neglected to identify the presence of the semipermeable membrane in osmosis (66% in stage 1 and 50% in stage 2) and were not able to properly indicate the kind of particles passing through the membrane (57% in stage 1 and 35% in stage 2), the textbooks’ definitions of osmosis were analyzed to identify whether they clearly indicated the presence of a semipermeable membrane in that process and specified the type of particles passing through the membrane. Additionally, we examined whether the textbook definitions 1) supported the idea that osmosis is limited only to water or liquids; 2) promoted the idea that osmosis is a special case of diffusion; or 3) indicated that the tonicity/concentration gradient is the driving force behind osmosis. Because the majority of students were unable to indicate the relationship between osmosis and diffusion (84% in stage 1 and 68% in stage 2), the textbooks’ definitions of plasmolysis were checked as to whether they indicated the cause–effect relationship between the processes. Despite the fact that the plasmolysis process is mandatory in the Polish high school core curriculum, some of the analyzed textbooks did not refer to it, and definitions or descriptions of the process were absent.

The results of the content analysis are summarized in Table 4. Every textbook we analyzed contained or supported at least one misconception identified as widespread among the university students. The results are consistent with findings from previous studies (e.g., Cho et al., 1985; Dikmenli and Cardak, 2004; Deshmukh and Deshmukh, 2011; Kose and Hasenekoglu, 2011). The most common misconception, which occurred in every textbook analyzed, was an indication that osmosis is limited to liquids.


Results of textbook content analysis

Because the majority of the respondents (60%) were familiar with aquaporins, we also examined whether textbooks contained a definition of the term. The concept did not occur in any of the five high school textbooks analyzed. It was, however, present in the five of the eight university textbooks. In university textbooks, the information on the structure and function of aquaporins was consistent. The textbooks clearly indicated that aquaporins are proteins that function as “water channels” (five textbooks) or “greatly facilitate the passage of water molecules through the membrane in certain cells” (one textbook).


Processes such as osmosis, diffusion, and plasmolysis are basic concepts in plant physiology. They are present in Poland’s middle and high school curricula, and pupils are supposed to be familiar with them. Unfortunately, students find these topics difficult to understand (e.g., Sanger et al., 2001). The results of our studies indicate that university biology students’ knowledge about the processes of diffusion, osmosis, and plasmolysis is poor and freighted with many misconceptions.

We observed difficulties in integrating students proper (scientific) knowledge into their general understanding. For example, students who were able to indicate the difference between plasmolysis and osmosis correctly identified structures where plasmolysis occurred, as did students who failed to notice this relationship. Similarly, the drawings of the students who were aware of the relationship between osmosis and plasmolysis included changes in the cell’s shape almost as often as students who were unaware of the association between the two processes.

The concept that caused students the least difficulties was aquaporins. The majority of students (60%) were familiar with this concept before the plant physiology course. It may seem surprising, since the concept is discussed only in university textbooks; however, during the first and second years of their studies, students participate in courses in which the topic of aquaporins is discussed.

We also observed a statistically significant decrease of several misconceptions after the plant physiology course, especially in the ability to define osmosis and distinguish between diffusion and osmosis. Significantly more students were aware that osmosis occurs in the presence of a semipermeable membrane and indicated correctly the type of particles taking part in the process (water or solvent). The proportion of answers indicating that the difference between osmosis and diffusion is associated with the direction of flow in relation to the concentration gradient significantly decreased, which suggests that more students recognized the spontaneity of both processes. A statistically significant increase was also observed in students’ ability to correctly illustrate cell behavior in solutions with different water potential. Students more frequently indicated the correct direction of water flow and changes in cell shape. We believe that this improvement was due to the possibility of directly observing the cell behavior during plasmolysis under the microscope and an improved ability to use the water potential concept in practice, since a significant increase in the proportion of the correct answers concerning particle movement in the context of water potential was also observed. Still, the frequency of occurrence of most misconceptions remained unchanged, which is, perhaps, not surprising, since they are extremely difficult to correct during the traditional process of education, a fact that is well documented in the literature (Winer et al., 2002; Bahar, 2003; Chi, 2013).

It is worth noting, however, that plant physiology courses include not only lectures but also laboratory practice, which might be assumed to be more effective than a traditional lecture. We suggest that students performing laboratory experiments are often unaware of the scientific ideas behind them. This observation is consistent with other research results present in the literature, suggesting the low effectiveness of practical work in supporting conceptual understanding of research findings (see Abrahams and Millar, 2008; Abrahams and Reiss, 2012). In students’ minds, the link between theory and practice, that is, between what they read and what they do in the laboratory, seems to be poor at this point. Bearing this fact in mind, it may be assumed that many students see textbooks as the most reliable sources of knowledge concerning osmosis and plasmolysis. The fact that many of the textbooks support students’ misconceptions makes attempting conceptual change even more difficult. Another serious obstacle to promoting conceptual change may be a low involvement of the learner in terms of being an active player in the process of knowledge restructuring (Sinatra and Pintrich, 2003). Our observations indicate that plants, in general, are not appreciated by students, and we find a description of “plant blindness” in the literature (Wandersee and Schussler, 1999).

Teachers need to be aware of findings such as ours and employ appropriate strategies. Planning and teaching any subject is a complex cognitive activity that requires not only content knowledge but also pedagogical, social, and other skills. Teachers with differentiated and integrated pedagogic understanding will have a greater ability to design and carry out lessons that will help students develop deep understanding of a concept (Magnusson et al., 1999). As Bednar and coauthors (1992) state, when designing a teaching process it is not so important to implement some particular theory of learning. The authors promote the idea that developers (teachers) need to be aware of their personal beliefs about the nature of learning and select concepts and strategies consistent with their beliefs. One of the major assumptions of constructivism is that knowledge evolves through social negotiation and through the evaluation of the viability of individual understanding (Savery and Duffy, 1995). Dewey’s “linking science” (Bednar et al., 1992) has to be introduced into regular teaching practice at university level. We assume that what is missing from the traditional laboratory is a collaborative group that can discuss, reconstruct conceptions, and test their own understanding of particular issues or phenomena during the learning process.

What is alarming is the fact that some misconceptions, such as the belief that osmosis and plasmolysis are unrelated or the conviction that osmosis is a typically biological process, dominate the scientific conceptions. The vast majority of our students are also unable to distinguish between diffusion and osmosis, which suggests that the source of such misconceptions may be the way that students are introduced to these phenomena. Indeed, definitions of osmosis in high schools and university textbooks may promote or even strengthen widespread miscomprehension. Among five osmosis definitions presented in high school textbooks, two did not mention the presence of the semipermeable membrane, thus enhancing the confusion between diffusion and osmosis. Another textbook indicates that, during osmosis, molecules pass through the “biological membrane,” which promotes the conviction that osmosis is typically a biological process. Moreover, three out of five textbook definitions indicated that water is the only type of molecule involved in osmosis, and only two of them defined molecules passing through the membrane as solvent molecules, thus creating a misconception that osmosis refers only to water, which is what 27% of students thought before taking the university plant physiology course. All analyzed textbook definitions limited osmosis to liquids, which—according to Hershey’s classification of misconceptions—is an undergeneralization (Hershey, 2004, 2005), since osmosis also applies to gases (Kramer and Myers, 2012). One of the university textbooks explained that osmosis is a case of diffusion, which is an obsolete theory (Kramer and Myers, 2012). In four of the five high school textbooks, osmosis is described in the context of tonicity or concentration. Only one showed osmosis in the context of water potential, which may explain the lack of knowledge of the concept before the plant physiology course.

In four of the five high school textbooks, osmosis was defined in the context of tonicity or concentration gradient, which is an oversimplification, since the gradient of hydrostatic pressure plays an equally important role in regulating osmotic flow as the solute concentration (Kramer and Myers, 2013). Moreover, we analyzed eight university textbooks and found that all eight definitions defined osmosis as a phenomenon limited to liquids, while six indicated water was the only compound involved in the process. In addition, six textbooks described osmosis as diffusion through a semipermeable membrane, and one did not mention that the process occurs in the presence of the semipermeable membrane. Another textbook stated that the process occurs through the “biological membrane.” Only one university textbook stated that osmosis is a physical not a biological process. Five university textbooks presented osmosis in the context of the concentration gradient and one in the context of tonicity. Only three of them referred to water potential. Although 90% of respondents indicated that they had become familiar with plasmolysis at an earlier (preuniversity) stage of education, the topic was mentioned in only two of the five school textbooks, and in only one case was it reported as the result of the osmotic flow of water from the cell. All the university textbooks contained a definition of plasmolysis. However, most of them described plasmolysis as the separation of cytoplasm from the cell wall as the result of water loss. Only one of them clearly mentioned the fact that plasmolysis occurs as an effect of osmotic flow. It can be assumed that the lack of direct embedding of plasmolysis in the context of osmosis makes it difficult for students to link the two phenomena.

We conclude that the vast majority of osmosis definitions found in both high school and university textbooks include misconceptions that correspond with those widespread among university students. They belong mainly to categories of misconceptions described as “undergeneralization” and “obsolete theory” (Hershey, 2004, 2005). To limit the confusion related to osmosis, we recommend a more interdisciplinary approach to the issue in biology textbooks. The fact that osmosis is a physical not a biological process should be highlighted, and the definition of osmosis should be reformulated following Kramer and Myers’s (2012) notion that “osmosis is the flow of solvent across a semipermeable membrane from a region of lower to higher solute concentration.” In the course of discussing osmosis, the types and properties of solutions should be recalled, with an emphasis on solvent definition and its physical states, that is, not only liquid but also gas and solid (Averill, 2012).

Misconceptions concerning plasmolysis result mainly from students’ fragmentary knowledge and their difficulties in integrating it into their own conceptual overview. Our conclusion is that in both high school and university textbooks the cause-and-effect relationship between osmosis and plasmolysis could be emphasized more strongly.

Texts that are not free from mistakes, misconceptions, or understatements might serve didactical purposes. According to Posner et al. (1982), the major goal of teaching and learning in the process of conceptual change is to create cognitive conflict to make learners feel dissatisfied with their existing conceptions. The scientific conception has to be intelligible, plausible, and fruitful in order to serve as a new one for the learner and to lead to successful conceptual change. These conditions are often difficult to meet, particularly when teaching large classes.

We recommend introducing into regular seminars or even lectures a method based on the constructivist theory of learning that is called “questioning the author” (QtA; Beck et al., 1996; Beck and McKeown, 2006). QtA was designed to facilitate student interactions with text and build greater understanding by teaching students to question the ideas presented while they are reading (Beck and McKeown, 2002, 2006). At first, the method was used with younger students who, according to Beck and McKeown (2001), are able to handle a challenging content. QtA involves the teacher stopping at predetermined points in a text or in a classroom discussion and asking open-ended questions. It has been used at higher levels of education, for example, in the project ETOS, which was designed to support science teaching and learning in primary schools (years 4–6) and junior secondary schools (years 1–3; Basin´ska et al., 2012). In the project, QtA was mostly used as a technique for modeling classroom discussions and analyzing scientific animations. It was also introduced at high school and university levels (Rybska and Basin´ska, 2014). The opening questions that usually start the discussion are “What is this all about?” and “What do you think?” This method allows students to use their own language. Teachers use the students’ words to reinforce the correct part of their answers or to discuss with them what the concept could be if this incorrect conception appeared in real life.

QtA seems to be an alternative to teacher-oriented classroom conversations, facilitating collaborative learning and discourse. Osborne (2010) writes that collaborative learning provides opportunities for students to engage in discourse and argumentation as a means of enhancing students’ conceptual understanding, skills, and capabilities for scientific reasoning. As one of the “ideal” hallmarks of the scientist is critical and rational scepticism, the lack of opportunities to develop the ability to reason and argue scientifically would appear to be a significant weakness in contemporary educational practices. In short, knowing what is wrong matters as much as knowing what is right. There is a limitation in introducing the QtA method, as it requires university teachers to become familiar with it and to be willing to implement it into their regular teaching activities. Applying the QtA method on a regular basis might allow teachers to become familiar with students’ preexisting knowledge and offer students an opportunity to ask and seek answers and—what is even more important—give them the right to be wrong, because every conception is discussed in depth.


Students’ misconceptions are extremely difficult to change during the traditional course comprising lectures and practical exercises. Our finding is consistent with previous research concerning conceptual change (see Bahar, 2003). In our opinion, it is important to apply specific didactical methods, for example, QtA, when teaching about water relations in plant cells, because it enables continuous monitoring of students’ current knowledge so as to help them acquire a more scientific understanding of particular concepts.


We thank Prof. Justin Dillon for his suggestions and kind review of the manuscript.


  • Abrahams I, Millar R. Does practical work really work? A study of the effectiveness of practical work as a teaching and learning method in school science. Int J Sci Educ. 2008;30:1945–1969.
  • Abrahams I, Reiss MJ. Practical work: its effectiveness in primary and secondary schools in England. J Res Sci Teach. 2012;49:1035–1055.
  • Averill BA. In: Principles of General Chemistry, version 1.0, chap 13. 2012. Solutions. (accessed 20 June 2014)
  • Bahar M. Misconceptions in biology education and conceptual change strategies. Educ Sci. 2003;3:55–64.
  • Basińska A, Pietrala D, Cole R, Dziubalska-Kołaczyk K. ETOS–innowacyjne narzędzie wspomagające nauczanie i uczenie się przedmiotów przyrodniczych. Studia edukacyjne. 2012;23/2012:229–248.
  • Beck IL, McKeown MG. Text talk: capturing the benefits of read-aloud experiences for young children. Read Teach. 2001;55:10–20.
  • Beck IL, McKeown MG. Questioning the author: making sense of social studies. Educ Leadersh. 2002;59:44–47.
  • Beck IL, McKeown MG. Improving Comprehension with Questioning the Author: A Fresh and Expanded View of a Powerful Approach. New York: Scholastic; 2006.
  • Beck IL, McKeown MG, Sandora C, Kucan L, Worthy J. Questioning the Author: a yearlong classroom implementation to engage students with text. Elem Sch J. 1996;96:385–414.
  • Bednar AK, Cunningham D, Duffy TM, Perry JD. Theory into practice: how do we link. In: Duffy TM, Jonassen DH, editors. Constructivism and the Technology of Instruction: A Conversation. Hillsdale, NJ: Erlbaum; 1992. pp. 17–34.
  • Bluman AG. Elementary Statistics: A Step by Step Approach. 7th ed. New York: McGraw-Hill Humanities; 2009.
  • Chi MTH. Two kinds and four sub-types of misconceived knowledge, ways to change it, and the learning outcomes. In: Vosniadou S, editor. International Handbook of Research on Conceptual Change. 2nd ed. New York: Psychology Press; 2013. pp. 49–70.
  • Chi MTH, Roscoe RD. The processes and challenges of conceptual change. In: Limon M, Mason L, editors. Reconsidering Conceptual Change: Issues in Theory and Practice. Dordrecht, Netherlands: Kluwer Academic; 2002. pp. 3–27.
  • Cho HH, Kahle JB, Nordland FH. An investigation of high school biology textbooks as sources of misconceptions and difficulties in genetics and some suggestions for teaching genetics. Sci Educ. 1985;69:707–719.
  • Creswell JW. Research Design Qualitative and Quantitative Approaches. Thousand Oaks, CA: Sage; 1994.
  • Deshmukh N, Deshmukh V. Textbook: a source of misconceptions at the secondary school level. In: Chunawala S, Kharatmal M, editors. Proceedings of epiSTEME 4—International Conference to Review Research on Science, Technology and Mathematics Education; Mumbai, India. Macmillan; 2011. pp. 144–149.
  • Dikmenli M. Misconceptions of cell division held by student teachers in biology: a drawing analysis. Sci Res Essay. 2010;5:235–247.
  • Dikmenli M, Cardak O. A study on misconceptions in the 9th grade high school biology textbooks. Eurasian J Educ Res. 2004;17:130–141.
  • Driver R. Students’ conceptions and the learning of science. Int J Sci Educ. 1989;11:481–490.
  • Edling A. Doctoral dissertation. Uppsala, Sweden: Uppsala University; 2006. Abstraction and authority in textbooks: the textual paths towards specialized language. (accessed 15 June 2014)
  • Freedman JC, Sperelakis N. Diffusion and permeability. In: Sperelakis N, editor. Cell Physiology Source Book. 4th ed. San Diego, CA: Academic; 2012. pp. 113–120.
  • Friedler Y, Amir R, Tamir P. High school students’ difficulties in understanding osmosis. Int J Sci Educ. 1987;9:541–551.
  • Glaser BG, Strauss AL. The Discovery of Grounded Theory: Strategies for Qualitative Research. Chicago, IL: Aldine; 1967.
  • Hershey DR. Avoid misconceptions when teaching about plants. 2004.
  • Hershey DR. More misconceptions to avoid when teaching about plants. 2005. (accessed 20 June 2014)
  • Hsieh HF, Shannon SE. Three approaches to qualitative content analysis. Qual Health Res. 2005;15:1277–1288.[PubMed]
  • Huck SW. In: Reading Statistics and Research. Boston: Pearson Education; 2008. Inferences on percentages, proportions, and frequencies; pp. 404–434.
  • Johansson I, Karlsson M, Johanson U, Larsson C, Kjellbom P. The role of aquaporins in cellular and whole plant water balance. Biochim Biophys Acta. 2000;1465:324–342.[PubMed]
  • Kaid LL. Content analysis. In: Emmert P, Barker LL, editors. Measurement of Communication Behavior. New York: Longman; 1989. pp. 197–217.
  • Kose EO, Hasenekoglu I. Misconceptions and alternative concepts in biology textbooks: nucleic acids and protein synthesis. Energy Educ Sci Technol B. 2011;3:403–410.
  • Kramer EM, Myers DR. Five popular misconceptions about osmosis. Am J Phys. 2012;80:694–699.
  • Kramer EM, Myers DR. Osmosis is not driven by water dilution. Trends Plant Sci. 2013;18:195–197.[PubMed]
  • Krippendorff K. Content analysis. In: Barnouw E, Gerbner G, Schramm W, Worth TL, Gross L, editors. International Encyclopedia of Communication. Vol. 1. New York: Oxford University Press; 1989. pp. 403–407. (accessed 28 May 2014)
  • Magnusson S, Krajcik J, Borko H. In: Examining Pedagogical Content Knowledge. Dordrecht, Netherlands: Springer; 1999. Nature, sources, and development of pedagogical content knowledge for science teaching; pp. 95–132.
  • Meir E, Perry J, Stal D, Maruca S, Klopfer E. How effective are simulated molecular-level experiments for teaching diffusion and osmosis. Cell Biol Educ. 2005;4:235–248.[PMC free article][PubMed]

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