2. What is the main adaptive advantage of the C₄ and CAM photosynthesis strategies over the C₃ strategy?
(A) They help the plant synthesize glucose efficiently under dry conditions.
(B) They allow the plant to fix carbon under conditions of low CO₂.
(C) They allow the plant to fix carbon in cool conditions.
(D) They make it possible for the plant to use the Calvin cycle at night.

98.Look at the table, at which stage is the speaker addressing? (A) Orientation Session. (B) Retirement Celebration. (C) Trivia Challenge. (D) Karaoke Night.

99.What have Connie and Wendy successfully transformed in their work? (A) Challenges into opportunities. (B) Transactions into losses. (C) Camaraderie into rivalry. (D) Commitment into indifference.

100.What is the lasting impact that Connie and Wendy have had on their team? (A) They have caused division and conflicts. (B) They have created a culture of indifference. (C) They have fostered camaraderie and inspiration. (D) They have left no impact at all.

1. The development of heart disease can result from a diet high in (A)protein. (B) unsaturated fats. (C) saturated fats. (D) sugars.

3. RNA interference (RNAi) can be used by (A) researchers to induce the production of more mRNA. (B) researchers to artificially turn on gene expression. (C) viruses to stop the production of new proteins. (D) cells to prevent infections from double-stranded RNA viruses.

4. Sympatric speciation commonly occurs through_______ in plants but is more likely to occur through_______ in animals. (A)polyploidy； habitat differentiation and sexual selection (B) habitat differentiation and sexual selection； polyploidy (C)asexual reproduction；chromosome duplications (D) self-pollination； polyploidy and other genetic mechanisms 

5. Mycorrhizal fungi are sometimes purposely introduced to new areas of land that are used for growing plants for commercial uses (e.g., landscaping, crop production, timber production). What would be the benefit of doing this? (A) The fungi absorb toxic pesticides from the ground. (B) The fungi help facilitate horticulture, agriculture, and forestry. (C) The fungi promote the evolution of new fungus species. (D) The fungi prevent competitive plant species from growing.

6. Homeostasis (A) is the maintenance of a relatively constant internal state. (B) results from hormone imbalance. (C) occurs when the external environment changes to match the internal environment. (D) is the way the internal environment influences the external environment.

7. The second vaccination is beneficial because it (A) contains mast cells that survive longer than 4-5 days. (B) stimulates production of a higher concentration of antibodies in the bloodstream. (C) requires two injections to stimulate antibody formation. (D) keeps previously produced cytotoxic T cells circulating in the bloodstream.

8. Our biological clock, which regulates the sleep-wake cycle, is housed within the (A) cerebrum. (B) hypothalamus. (C) cerebellum. (D) brainstem.