Study topics for Test 2
Topics covered: # 4, 5 and 6.

Note from 10/7/2008. This is the complete final list of the study topics.
Test format: 45-50 multiple choice, short answer and fill-in-blank questions.

1. Define soil and explain the five major factors involved in soil formation.
2. Describe soil stratification and briefly characterize each soil horizon.
3. Explain what determines soil texture. What is water holding capacity of the soil? How is it determined? Define the four main states of the soil (saturated, field capacity, wilting point and hygroscopic point). In which states there is water available for plant growth?
4. Explain how water holding capacity is related to the soil texture. Which  soil texture have the maximum water holding capacity?
5. Define and explain the cation exchange capacity (CEC) of the soil. Define micelle. What is the role of permanent charge and pH dependent charge in soil CEC? How is CEC related to soil fertility and why?
6. Name 12 major soil orders. Give an example of a typical soil type for the following biomes: 1) tropical rainforest; 2) deciduous hickory-oak forest (e.g. as in North Carolina); 3) desert; 4) tundra. Explain how prevailing climatic conditions in each of these 4 biomes,  and texture and mineral composition of each type of these 4 types of soils will affect their stratification and fertility.
7. Give definition of Darwinian adaptation. Give examples of biochemical, morphological, physiological and behavioral adaptations to the environment (you can draw examples from this course or any other biology courses).
8. Give definition of natural selection. Explain what genotype and phenotype is. Explain how selection can increase frequencies of  particular genes through acting on phenotype.
9. What are the 4 main assumptions of theory of natural selection?
10. Define Darwinian fitness. Be able to calculate fitness of a genotype if given the  total number of offspring produced, and number or % of offspring surviving till maturity for all genotypes in the population. What is the maximum and minimum value of Darwinian fitness?
11. Explain how difference in fitness between different genotypes will result in an increase or decrease of frequency of corresponding alleles in the next generation. Be able to determine from the fitness of different genotypes, which one will increase in frequency with time in a population.
12. Describe two major types of trophic biology of organisms. Define autotrophs and heterotrophs. What are their sources of energy and carbon?
13. Explain how different types of trophic biology are distributed among the 5 major biological kingdoms. Give examples of chemosynthetic autotrophs , photosynthetic autotrophs and heterotrophs for those kingdoms that have more than 1 type of trophic biology.
14. Define PAR and give wavelength for PAR. What are the absorbance maxima of the chlorophyll a? Why terrestrial plants appear green in color?
15. Give summary reactions for light-dependent and light-independent parts of the plant photosynthesis. Explain in which part of the photosynthesis carbon fixation occurs, and in which - production of sugars from simple organic molecules. What is the role of the light-dependent reactions in photosynthesis?
16. Compare C3, C4 and CAM pathways of photosynthesis. Draw simplified pathways for all 3 types of photosynthesis including the following compounds (as appropriate):  RUBISCO, RuBP, C3 compounds (e.g. PGA), C4 acids (e.g. malate or aspartate), PEP, PEPCK, simple sugars (don't forget to indicate the role of RUBISCO, RuBP and C3 compounds in C4 and CAM photosynthesis!).
17. What are key enzymes responsible for initial fixation of atmospheric CO2 in C3, C4 and CAM pathways of photosynthesis? Compare the properties of these enzymes: affinity for CO2, propensity to catalyze photorespiration. Define photorespiration.Why and when it occurs? Explain how C4 and CAM photosynthesis overcome the problem of photorespiration.
18. Explain how different pathways of photosynthesis allow plants to survive and reproduce in different types of the environments (wet and cool vs hot and dry). Explain the role of C4 and CAM pathways for water conservation by plants. Compare advantages and disadvantages of different pathways in hot, arid vs cool, moist environments.
19. Explain how plants adapt to different light intensity. Define and explain light compensation point and light saturation point.  Which physiological process in plants causes CO2 release? Which physiological process causes CO2 uptake?
20. How do light compensation point and light saturation points differ between sun-loving and shade-tolerant plants? Be able to determine which of the 2 plant species is more shade-tolerant if given values of light compensation or light saturation points for these 2 species.
21. Define light attenuation and explain how wavelength of PAR change with increasing depth in aquatic environments. What is euphotic zone and how deep it is in different parts of the ocean or large lakes (coast vs open waters)?
22. Explain how different pigments allow algae and cyanobacteria to grow in deep waters. Give examples of the pigments that absorb light in the blue-green part of the spectrum. Why are chlorophyll a-containing plants unable to survive in deep waters?
23. Define water potential in the soil and in plants. Explain what is a cohesion theory of water transport in plants. How does water evaporation from plant foliage assist in water transport?
24. Explain how water potential determines the direction of water flow between soil and plant roots (I will give you values of water potential in the soil and the plant roots and ask you to determine whether water uptake, water loss by the plant or no water movement will occur). 
25. In which 2 states of the soil the water potential in the soil is higher than the water potential in plants? In which 2 states of the soil the water potential in the soil is equal to or lower than the water potential in plants? In which of those 4 states is the water uptake by plants possible and when it is not?
26. List major macronutrients and micronutrients required for plant growth. Using example of nitrogen, explain how the rate of nutrient uptake depend on the concentration of the nutrient in the soil.
27. Describe how the rate of photosynthesis of a plant depend on the rate of N uptake. Be able to draw a typical saturation curve and to determine saturation point for the curve. Compare saturation curves of the plants adapted to soils with high and low N concentrations.
28. List 3 major physiological and morphological adaptations of plants to low-nutrient conditions (growth rate, root morphology, leaf longevity) and explain how they help plants survive when soil levels of bioavailable nitrogen are low.