28. Which of the following is a phenolic compound with a structure similar to aspirin?
(A) systemin.
(B) florigen.
(C) brassinosteroids.
(D) salicylic acids.

(E) jasmonic acid.

24. Which of the following does NOT involve the use of tissue culture?(A) micropropagation.(B) clonal propagation.(C) protoplast fusion.(D) hyhroponics.(E) meristem culture.

25. In the process of stomatal closing, which of the following events occurs first?(A) Water moves out of guard cells.(B) Water moves into guard cells.(C) Guard cell turgor pressure decreases.(D) Guard cell solute concentration declines.(E) Guard cell water potential increases.

26. Which of the following is the order in which flower parts are attached to the receptacle, from lowest or highest?(A) Petals ＞ sepals ＞ stamens ＞ carpels.(B) Sepals ＞ petals ＞ stamens ＞ carpels.(C) Sepals ＞ stamens ＞ petals ＞ carpels.(D) Sepals ＞ petals ＞ carpels ＞ stamens.

27. To move sucrose molecules from leaves to roots, the sucrose molecules must enter sieve elements. This involves: (A) moving the molecules through plasmodesmata. (B) the use of ATP to pump sucrose molecules with their concentration gradient across the plasma membrane. (C) the use of ATP to pump sucrose molecules against their concentration gradient across the plasma membrane. (D) the pumping of sucrose molecules across the plasma membrane with their concentration gradient without the use of ATP. (E) the pumping of sucrose molecules across the plasma membrane against their concentration gradient without the use of ATP.

29. Which of the following events is NOT associated with seed germination?(A) imbibition.(B) activation of existing enzymes.(C) synthesis of new enzymes.(D) synthesis of food reserves.(E) initiation of cell division and cell enlargement.

30. Which of the following statements about tropical rainforests is FALSE?(A) They contain plants that are either evergreen or leafless for short periods.(B) There is strong competition for light.(C) There is abundant plant cover beneath the trees.(D) The trees have an abundance of epiphytes.(E) They occur where temperatures and rainfall are relatively consistent.

1. Which statement is NOT true in a vascular plant with a heterosporous life cycle? (A) Both male and female gametophytes develop within the sporophyte generation. (B) Microspores develop into male gametophytes, while megaspores develop into female gametophytes. (C) Fertilization results in a diploid zygote that develops into the next sporophyte generation. (D) The gametophyte generation is independent and free-living.

2. Which of the following characteristics is NOT shared by both non-vascular and vascular plants? (A) Presence of cell walls composed of cellulose (B) Sexual reproduction involving gametes (C) Dependence on water for sperm transfer (D) Embryonic development protected by a multicellular structure

3. Transpiration is the process by which plants lose water primarily through which structures? (A) Roots (B) Stems (C) Leaves (D) Flowers

4. An example of convergent evolution is: (A) Humans and chimpanzees having five fingers (B) Owls and hawks having sharp beaks for hunting (C) Dolphins and sharks having streamlined bodies (D) Lions and tigers having different prey preferences