7. Which of the following is not the regulatory mechanism of gene expression at the post-transcriptional level?
(A) alternative RNA splicing
(B) protein degradation
(C) miRNA-mediated gene silencing
(D) use of different repressors

3. Which off the following statements about evolution is true? (A) Individuals evolve within the span of their own lifetimes. (B) Organisms evolve structures in response to needs. (C) Evolution is intentional and purposeful. (D) Evolution can result in adaptations.

4. The cells of a spider and a tiger are, on average, the same small size； a tiger just has more of them. What is the main advantage of small cell size? (A) It takes less energy to make an organism out of small cells. (B) Small cells require less oxygen than large cells do. (C) Small cells can better take up sufficient nutrients and oxygen to provide for their need. (D) A small cell has a less plasma membrane surface area than a large cell does.

5. Organisms belonging to the kingdom Plantae _______ . (A) are photosynthetic (B) obtain food by decomposing the dead organisms (C) are unicellular and lack a nucleus (D) are multicellular and lack a nucleus

複選題6. Red-green color blindness is a sex-linked recessive trait (i.e., the responsible gene is on the X chromosome). From a marriage between a woman heterozygous for color-blindness gene and a normal vision man, which of the following predictions for their children is correct? (A) all the boys are color blind (B) half of the boys are color blind (C) half of the girls have normal vision (D) ail the girls are heterozygous carrier

8. A plasma cell produces thousands of antibodies per second for release into the body. What kind of organelles would you expect to be very prominent within the cell? (A) nucleus (B) endoplasmic reticulum (C) lysosomes (D) microtubules

9. A drug that interferes with microtubule formation is likely to completely disrupt _______ . (A) the amoeboid movement of a cell. (B) the function of lysosomes (C) contraction of muscle cells (D) the movements of sperm cells

複選題10. Which of the following scenarios describes an example of epistasis? (A) Albino corn snake result from animals having recessive genotypes for each of two genes. (B) In many mammals one genotype (ee) prevents any fur color from developing. (C) In fruit flies white eyes can be due alleles of a gene on the X chromosome or a combination of other genes. (D) In cacti (仙人掌),there several genes control the type of spines.

11. If, on average, 48% of the loci in a species' gene pool are heterozygous, then the average homozygosity of the species should be _______ . (A) 24% (B)48% (C) 26% (D) 52%

12. The Casparian strip of the endodermis stops water from the _______ before it reaches the stele. (A) symplastic pathway only (B) transmembrane and symplastic pathways (C) transmembrane pathway only (D) apoplastic pathway only

13. What is the function of reverse transcriptase in retroviruses? (A) It uses viral RNA as a template for making complementary RNA strands. (B) It uses viral RNA as a template for DNA synthesis. (C) It uses host cell RNA as a template for viral DNA synthesis. (D) It translates viral RNA into capsid proteins.