8. Nitrogen fixation is a process that _______.
(A) recycles nitrogen compounds from dead and decaying materials
(B) converts ammonia to nitrate
(C) converts nitrogen gas into ammonia
(D) releases nitrate from amino acids
(E) B and C

4. Genomic imprinting, DNA methylation, and histone acetylation are all examples of _________.(A) genetic mutation (B) chromosomal rearrangements (C) epigenetic phenomena (D) karyotypes (E) translocation

5. What is the enzymatic function of restriction enzymes? (A) to add new nucleotides to the growing strand of DNA (B) to join nucleotides during replication (C) to join nucleotides during transcription (D) to cleave nucleic acids at specific sites (E) to repair breaks in sugar-phosphate backbones

6. Which of the following are sugar-transporting cells in angiosperms? (A) sieve-tube elements (B) parenchyma cells (D) sclerenchyma cells (E) tracheids and vessel elements (C) collenchyma cells

7. What is the role of proton pumps in root hair cells? (A) establish ATP gradients (B) acquire minerals from the soil(C) pressurize xylem transport (D) eliminate excess electrons (E) A and Donly

9. Where does meiosis occur in flowering plants? (A) megasporocyte (B) microsporocyte (C) endosperm (D) pollen tube (E) megasporocyte and microsporocyte

10. Plants growing in a partially dark environment will grow toward light in a response called phototropism. Choose the incorrect statement regarding phototropism. (A) It is caused by a chemical signal. (B) One chemical involved is auxin. (C) Auxin causes a growth increase on one side of the stem. (D) Auxin causes a decrease in growth on the side of the stem exposed to light. (E) Removing the apical meristem prevents phototropism.

11. Why is the velocity of blood flow the lowest in capillaries? (A) The capillary walls are too thin to maintain the velocity of blood flow in capillaries. (B) Capillaries are far from the heart, and blood flow slows as the distance from the heart increases. (C) The diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate. (D) The total surface area of the capillaries is larger than the total surface area of the arterioles. (E) The systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle.

12. The MHC (major histocompatibility complex) is important in a T cell's ability to_______. (A) identify specific viruses (B) recognize specific parasitic pathogens (C) distinguish self from nonself (D) identify specific bacterial pathogens (E) recognize differences between normal and cancer cells

13. What is the main nitrogenous waste excreted by birds? (A) uric acid (B)urea (C) nitrate (D) ammonia (E) nitrite

14. Prostaglandins are local regulators whose basic structure is derived from_______.(A) oligosaccharides (B) fatty acids (C)steroids(D)amino acids (E) nitric oxide