The Study Questions below will guide your study for lecture exams in LIFE 2023 as taught by Steve Herbert in the Fall of 2012 at the University of Wyoming. To prepare for exams, write thoughtful, generous answers to these questions using your text and lecture notes as your primary sources. After you have worked on your answers alone, I strongly recommend that you meet with other students in a study group to discuss them. You may also raise these Study Questions in lecture and during meetings with the instructor. Exams will be based on the correct and complete answers to the Study Questions.
Study Questions for Exam 4
Updated 12 5-2012
1. Monthly average measurements of atmospheric CO2 since 1957 show three interesting features of the global carbon cycle (see the figure at http://www.research.noaa.gov/climate/images/carboncycle_co2mm.png). What are they?
2. Production of fuel ethanol from corn is an early biofuel technology. What are its strengths and weaknesses?
3. Briefly describe strengths and weaknesses for three other possible sources of biofuels.
4. Matching question alert. Be prepared to recognize descriptions of the following features of fungi and know which fungal phyla they are found in.
closed mitosis
flagella
zygospores
asci
basidiospores
clamp connections
cross walls in hyphae
glycogen
chitin
5. Fungi often form associations with plants. Some of these are good for the plant and some are bad for the plant. Describe one case of each.
6. The genera Penicillium and Aspergillus have been grouped into the "deuteromycetes" for many years even though they exhibit conidia like members of phylum Ascomycota. What was the reason for putting these two genera in the deuteromycetes? Some people now put these two genera in phylum Ascomycota. What change has led to this?
7. Matching question alert. Be prepared to identify statements that are defining of the following fungi:
Rhizopus stolonifer
Pilobolus sp.
Penicillium sp.
Aspergillus flavus
Tuber melanosporum
Boletus edulis
Puccinia graminis
8. What would be some advantages of dispersing spores with a basidiocarp rather than a zygosporangium?
9. EXTRA CREDIT in Rhizopus stolonifer, Tuber melanosporum, Aspergillus flavus, and Boletus edulis, where would you find karyogamy and meiosis occurring?
10. What are some of the shared derived traits that suggest green algae were the ancestors of land plants?
11. What is meant by the phrase "alternation of generations? Compare and contrast the alternation of generations in mosses with that in angiosperms.
12. Does meiosis in land plants produce spores or gametes? Explain using examples.
13. Conifer and angiosperm embryos are fed by materials that are provided by their parent gametophytes. Compare and contrast the two cases.
14. Our current understanding of land plant evolution indicates that reduction and protection of the haploid gametophyte by the diploid sporophyte promotes success in the terrestrial environment. What are some possible mechanisms of this effect?
15. Matching question alert. Be able to match the following features with different groups of land plants that we discussed and, in some cases, how the features may improve fitness in the terrestrial environment.
phycoplast
phragomplast
apical flagellar insertion
sub-apical flagellar insertion
oogamy
isogamy
sterile jacket
epidermis and cuticle
free-living gametophyte
reduced gametophyte protected by sporophyte
lignified xylem
well-developed branching root system
swimming sperm
pollen
seeds
flowers and fruit
polyembryony
double fertilization
vessels in xylem
16. Matching question alert. Be able to match the following genera with traits that may distinguish them or that make them significant in some way.
Chlamydomonas
Volvox
Chara
Sphagnum
Marchantia
Equisetum
Polystichum
Psilotum
Ginkgo
Ephedra
Cycas
Pinus
Lilium
Festuca arundinacea
17. How might seeds have contributed to the success of gymnosperms and flowering plants in the terrestrial environment?
18. Flowers often serve to attract insect pollinators to flowering plants and in some cases are highly specialized to attract specific insects. What advantages might insect pollination confer on flowering plants? What highly successful, recently evolved group of land plants does not use insect pollination?
19. We described several great moments in the proposed evolutionary history of plants. Briefly describe three of these.
---------------- Review questions for cumulative part of Exam 4 -------------------
20. We discussed 4 practical rules that increase the speed and accuracy of science. Briefly describe each of these and include how they are helpful.
21. What are histones? How does the absence of histones in chloroplasts support the Endosymbiont Hypothesis? How do chloroplast ribosomes and the nucleotide sequence of the chloroplast RNA polymerase also support the Endosymbiont Hypothesis?
23. Describe the advantages of the fast and inexpensive way in which plants grow. How do the large central vacuole and the plant cell wall make this inexpensive growth possible?
24. Matching question alert. Be prepared to recognize descriptions of the following terms:
apical meristems
lateral meristems
vascular cambium
cork cambium
totipotency
transformation
parenchyma cells
collenchyma cells
sclerenchyma cells
fibers
epidermal cell
trichome
root hair
guard cell
periderm
cork cell
phloem
sieve tube member
companion cell
xylem
vessel element
tracheid
xylem parenchyma
25. We have discussed three roles for H+ ATPases in the physiology of plants. What are they?
26. How does the plant hormone ethylene cause plant cells to become thicker and shorter? Under what circumstances would this be an adaptive response to environmental signals? Describe one other plant hormone and how it functions in plants.
27. Divergent speciation is a concept that explains the process of speciation relatively well. How is does reproductive isolation foster divergent speciation?
28. Many plants, fungi, and algae exhibit both sexual and asexual reproduction. What are the risks and benefits of each in terms of the survival of populations?
29. In Meiosis, what is the difference between a pair of chromatids and a pair of homologous chromosomes? Which is separated in Meiosis I and which is separated in Meiosis II.
30. Describe the differences between allopolyploidy and autopolyploidy. How is it that an allopolyploidy event must often be followed by an autopolyploidy event to yield a new species?
Study Questions for Exam 3
Updated 11-14-2012
1. Aquaporins are channel proteins that allow water to move quickly through cell membranes. What makes diffusion of water through aquaporins faster than diffusion of water through the lipid bilayer of cell membranes?
2. What three external signals influence the opening of stomata?
3. Guard cells open their stomate by increasing the solutes in their cytosol and vacuole. What solutes increase in this process and where do they come from? How does the increase in solute concentration in the guard cells cause their stomate to open?
4. A corn plant is grown such that the roots are divided into two separate plant pots. One of these is kept well-watered and supplies the shoot with plenty of water. The other pot is allowed to dry out as an experiment and all the stomata of the corn plant close, even though it is a sunny day, the shoot has plenty of water, and CO2 levels in the leaf are very low owing to rapid photosynthesis. Explain.
5. We have discussed three roles for H+ ATPases in the physiology of plants. What are they?
6. Increasing the starch synthesis in potato tuber by adding a starch synthesis gene from bacteria will cause the potato to be larger than normal. Explain this in terms of translocation.
7. What is a photoreceptor and how does it work? Give two examples of photoreceptors known in plants. For each of these two photoreceptors, give two examples of plant functions they influence.
8. There are 5 genes for phytochromes in the lab plant Arabidopsis. Their gene sequences are very similar but not identical. What might be the advantage of having 5 genes for this protein? If there were no advantage to having each of these 5 genes, what would you expect to happen to one or more of the genes over time?
9. What is the difference between cellulose microfibrils and cortical microtubules in plants? What are they made of? Where are they found? What do they do?
10. Matching question alert. Be prepared to recognize descriptions of the following terms:
water use efficiency
phototropins
phytochromes
co-transporter
channel
membrane potential
H+/Cl- symporter
H+/ sucrose symporter
auxins
cytokinins
ethylene
abscisic acid
gibberellic acid
11. The Casparian strip of plant roots allows the solute composition of water in the xylem to be different than the solute composition of the surrounding soil water. Explain.
12. During a drought, some plants produce "compatible solutes" to retain water in their cells. Give three examples of compatible solutes and explain how they work.
13. Biological evolution is a theory that explains a number of observations about living things. Briefly describe 4 of these observations. Briefly describe one way in which evolutionary biology is applied in medicine or agriculture.
14. Many plants, fungi, and algae exhibit both sexual and asexual reproduction. What are the risks and benefits of each in terms of the survival of populations?
15. What events in the process of sexual reproduction act primarily to generate novel combinations of alleles in individuals of the population? What events in sexual reproduction can duplicate genes?
16. We have discussed the hypothesis that duplication of genes fosters the evolution of new genes with novel or improved functions. Explain this concept.
17. Describe the differences between allopolyploidy and autopolyploidy. How is it that an allopolyploidy event must often be followed by an autopolyploidy event to yield a new species?
18. What is the difference between a point mutation and a chromosomal deletion mutation?
19. In Meiosis, what is the difference between a pair of chromatids and a pair of homologous chromosomes? Which is separated in Meiosis I and which is separated in Meiosis II.
20. Matching question alert. Be prepared to recognize descriptions of the following terms:
chromatid
homologue (referring to a type of chromosome)
equal crossing over
unequal crossing over
independent assortment
random fertilization
autopolyploidy
allopolyploidy
transposons
horizontal gene transfer
phyletic speciation
divergent speciation
21. Give a short definition of evolutionary fitness. What is the relationship of fitness to the process of selection?
Is selection best characterized as a filter of genetic diversity or a force that shapes living things?
22. Phyletic speciation is an old concept for describing how species arise from different ancestors. What conditions would need to exist for phyletic speciation to occur? Give an example.
23. Divergent speciation is a concept that explains how speciation most often occurs. How is does reproductive isolation foster divergent speciation? Describe 3 ways in which plant populations might experience reproductive isolation.
24. Islands often have unique flora and fauna. How does the concept of divergent speciation by reproductive isolation explain this phenomenon?
25. Briefly describe two examples of mass extinctions in the history of life on Earth? Include a major group of plants or animals that declined significantly during the extinction andone hypothesis for what caused the extinction.
26. What is the punctuated equilibrium hypothesis that proposes to account for speciation rates at the beginning of the Cambrian geological period?
27. How is the filamentous form of most fungi an asset to their mode of feeding?
28. Fungal cell walls are constructed from microfibrils of the polymer chitin. How does chitin differ from cellulose? How does chitin in the fungal cell wall make it easier for fungi to digest plants as food?
29. Matching question alert. Be prepared to identify descriptions of the following terms:
dikaryotic
haploid
diploid
karyogamy
coenocytic
chitin
closed mitosis
30. Except for the flagellate zoospores of chytrids (water molds), there are no flagella in the fungi. If this is the case, how do fungi move into new territory?
31. Fungi are sources of many antibiotic chemicals, including penicillin. How might production of these chemicals be adaptive for some fungi? Fungi themselves are not susceptible to most antibiotics. Explain this?
32. The zygomycete Pilobolus exhibits a blue light response when it ejects its spore packets toward light. Many other fungi show responses to light and recent studies have found that they possess both phototropin-like and phytochrome-like photoreceptors. Bacteria also possess similar photoreceptors. What does this suggest about the evolution of photoreceptors in fungi and plants?
Study Questions for Exam 2
Updated 10-17-2012
1. In our discussion of photosynthetic CO2 assimilation, we noted that one triose phosphate may be used for starch or sucrose synthesis for every 3 carboxylation reactions. Explain this statement.
2. What is meant by the term "photorespiration"? How is it similar to aerobic respiration that occurs in mitochondria and how is it different?
3. The enzyme glycine decarboxylase converts 2 glycine molecules to one serine molecule plus one CO2 molecule during the process of photorespiration. A mutant plant that lacks a functional gene for the enzyme glycine decarboxylase dies if grown in air but lives if grown in air supplemented with 1% CO2. Explain this observation.
4. Some aquatic plants and algae minimize the oxygenation reaction of RUBISCO using transport proteins in their cell membranes. Explain.
5. How is the small carbohydrate malate used to pump CO2 into bundle sheath cells in C4 plants? How does this suppress the oxygenation reaction of RUBISCO?
6. Matching question alert. Be prepared to recognize descriptions of the following terms:
RUBISCO
PEPCase
photorespiration
oxygenation
processing of 2-phosphoglycolate
bundle sheath cell
C4 mesophyll cell
C4 plant
C3 plant
7. What are the three tissue systems of the plant body? Where are they found in the three organs of the plant body? What are their generalized functions?
8. Matching question alert. Be prepared to recognize a definition of the following terms:
parenchyma cells
collenchyma cells
sclerenchyma cells
fibers
sclereids
epidermis
epidermal cell
trichome
root hair
guard cell
periderm
cork cell
phloem
sieve tube member
companion cell
xylem
vessel element
tracheid
xylem parenchyma
9. If you wanted to grow an entire plant from a single plant cell, what tissue type would you take the cell from? Where in the plant body would you find cells of this type? What makes cells of this type well-suited to your purpose?
10. What is the cuticle of a leaf and what tissue is it associated with? What does the cuticle do for the leaf?
11. How do trichomes protect plants against insects? How do trichomes protect plants against dessication? What plant tissue are trichomes a part of?
12. Describe three ways in which the periderm and the epidermis of a woody plant are different? How are they the same?
13. Lignin and suberin are 2 organic compounds that plants produce in large amounts. Where are each of these found in the plant body? What functions do they perform for the plant?
14. Sieve tube members of phloem tissue lack nuclei. How does this suit them to their function? How do they get the proteins they need to perform their function? How do the P-proteins of sieve tube members contribute to their function?
15. How do the xylem parenchyma cells differ from the fiber, tracheid, and vessel element cells of the xylem?
16. When transplanting a tree during the growing season, it is recommended that a large amount of soil is kept in place around the roots and that the tree be staked loosely. Explain these recommendations in terms of root epidermis function and the effect of ethylene on cortical microtubules in the shoot tips.
17. Why does hardwood xylem conduct water faster than conifer wood xylem?
18. How do tracheids differ from vessel elements? How is it important that tracheids and vessel elements be reinforced with rings and other thickenings of their secondary cell wall?
19. In a pine tree, where are primary and secondary growth occurring during the summer?
20. Loss of tissue to an herbivore is common for plants. From your work in the laboratory, contrast the strategies of bean plants and corn plants for surviving herbivory events.
21. Protoderm, procambium, and ground meristem are regions of cells close to apical meristems. What tissue systems do they give rise to and where would you look for them in a shoot tip and a root tip?
22. Compare and contrast the development of branch shoots and branch roots. Include the role of auxin in both cases.
23. How does a floral meristem differ from a shoot apical meristem? What causes a shoot apical meristem to become a floral meristem?
24. What is the root cap and what is its role in root growth? What is the pericycle and what is its role in root growth?
25. In a cross section of a pine tree trunk, which xylem is older and which is younger? Which part of the phloem is younger and which is older?
26. What is the difference between primary and secondary growth in a woody plant? Where would you find some of each?
27. Water potential is a parameter used to describe how water moves through plants. What are the two parts of water potential in a plant body? Why do we not use water potential to describe the movement of water into and out of animal cells?
28. If the hydrostatic pressure (P) in a plant cell is 0.85 MPa and the osmotic pressure (π) is 1.10 MPa, what is the water potential of the cell? Would this cell gain or lose water if it were put in a sucrose solution having a water potential of -0.70 MPa? Would the plant cell have more dissolved solutes than the sucrose solution when it is first put in the sucrose solution? After water has moved and the sucrose solution and plant cell are in equilibrium, would the plant cell have more dissolved solutes than the sucrose solution? Explain.
29. What are the apoplast and symplast parts of the plant body? Do they typically have the same water potential? What makes this so? Despite having the same water potential, the apoplast of a plant may exhibit a negative P value (tension) while the symplast exhibits a positive P value (pressure). Explain.
30. Girdling a tree is the act of cutting away a thin strip of bark in a ring around the tree's trunk. After girdling, the tree will inevitably die. How does this small cut kill such a large organism?
31. Matching questions alert. Be prepared to recognize a definition of the following terms:
phragmoplast
cell plate
H+ ATPase
cortical microtubule
open growth
microtubule organizing center (MTOC)
wall loosening
turgor maintenance
auxin
ethylene
acid growth
32. How does the plant hormone ethylene cause plant cells to become thicker and shorter? Under what circumstances would this be an adaptive response to environmental signals?
33. In lab, we measured transpiration of geranium leaves with several treatments. What were the hypotheses that were tested with these experiments? For each hypothesis, which treatment was the control treatment and which was the experimental treatment?
Study Questions for Exam 1
Updated 9-18-2012
1. We discussed 3 ways in which you acquire knowledge: instinct, faith, and reason. Briefly describe each of these using examples. What are the advantages and disadvantages of each?
2. In the course of their research, individual scientists use instinct, faith, and reason to acquire their own personal knowledge but scientific knowledge comes from reason alone. Explain.
3. We discussed 4 practical rules that increase the speed and accuracy of science. Briefly describe each of these and include how they are helpful.
4. The application of science to medicine, public safety, and agriculture has been essential to a linear increase in average human lifespan in developed countries over the last 160 years. What problems has this success created?
5. The Green Revolution is credited with averting mass starvation that had been predicted to occur in India, Pakistan, and elsewhere in the 1980s. What problems has this success created?
6. Describe how the Demographic Transition Model for human population growth offers a hopeful scenario for your future.
7. The genetic modification of crop plants has begun to provide solutions to the problems created by the Green Revolution. Give a specific example that is supportive of this statement.
8. The cotyledons of bean seeds and the endosperm of corn seeds contain stored protein or carbohydrate. Why are these energy reserves necessary for developing seeds? How did the seeds obtain these energy reserves?
9. Root hairs of plant roots increase absorption of nutrients and water from the soil. How might they do this?
10. The coleoptile of monocot seedlings protects the shoot as it pushes through the soil. Look carefully at the one week old bean seedlings. Can you tell how dicot seedlings protect their shoots as they push through the soil?
11. Plants use sucrose for transport of C and E, starch for storage of C and E, and cellulose for structure. Describe how the chemical properties of these three molecules suit them to these uses.
12. Matching question alert. Be prepared to recognize the chemical structures of the following:
sucrose
starch
cellulose
triglycerides
13. Where is starch made and stored in plants?
14. Cellulose and starch are both polymers of glucose. How does the three-dimensional structure of cellulose make it stronger and harder to digest than starch?
15. What are the differences in chemical structure between saturated fats and unsaturated oils? How do these differences affect the freezing points of these fats and oils? What is the reason for chemically saturating (hydrogenating) vegetable oils before using them in processed foods?
16. Name 2 plant secondary compounds, including the class of secondary compounds to which they belong. Describe how they help the plant survive.
17. What are the three prominent features of plant cells that are absent from animal cells? How does each contribute to the immobile life strategy of plants?
18. Matching question alert. Be prepared to match the names of different plastid types with descriptions of them.
19. How do chromoplasts cause animals to help plants reproduce?
20. The Endosymbiont Hypothesis states that eukaryotic cells arose by combinations of prokaryotic cells. It is unclear how many eukaryotic organelles had a prokaryotic origin but most biologists agree that the animal ancestor experienced at least one endosymbiosis while the plant ancestor experienced at least two. Explain.
21. What are histones? How does the absence of histones in chloroplasts support the Endosymbiont Hypothesis? How do chloroplast ribosomes and the nucleotide sequence of the chloroplast RNA polymerase also support the Endosymbiont Hypothesis?
22. Describe the advantages of the fast and inexpensive way in which plants grow. How do the large central vacuole and the plant cell wall make this inexpensive growth possible?
23. Matching question alert. Be prepared to recognize descriptions of the following:
thylakoid membranes
tonoplast membrane
cellulose microfibril
pectin
lignin
primary cell wall
secondary cell wall
plasmodesmata
desmotubule
24. In a leaf, where is the chlorophyll found? Be as specific as possible.
25. The process of photosynthesis consumes H2O and CO2. What are the fates of the oxygen atoms in these molecules? Be as specific as possible. How are these fates essential to your survival?
26. Matching question alert. We divided photosynthesis into 3 steps: light harvesting, electron and proton transport, and CO2 assimilation. Be prepared to identify specific events that occur in each of these three steps.
27. Matching question alert. Be prepared to recognize descriptions of the following:
amylase
invertase
sucrose phosphate synthase
cellulase
cellulose synthase
trans and cis double bonds in fatty acids
RNA polymerase
signal transduction
RUBISCO
28. What kinds of molecules can pass between adjacent plant cells via their connecting plasmodesmata?