When root cells release the hormone abscisic acid (ABA), what is the result?
a. Solutes exit guard cells, causing stomata to close
b. Epidermal cell secretions increase.
c. Solutes enter guard cells, casing stomata to open.
d. Root hairs grow in the direction of water and nutrient availability.
a
You might also like to view...
If a tumor suppressor gene becomes mutated, which of the following is not true?
A. Genes that inhibit the cell cycle are not turned on. B. The cell cycle continues when it should not. C. Apoptosis is less likely to occur. D. Genes that encode enzymes that repair DNA are not turned on. E. A "gain-of function" mutation has occurred.
The frequent change in HIV surface proteins is a type of
A. mutualism. B. parasitism. C. coevolution. D. commensalism.
A small island has stable populations of plants and animals, including one species of hawk but no other large predators. A ship docks at the island, and the ship's cat escapes. If the cat was pregnant, what do you think the sailors are likely to find if they return ten years later?
A. The bird and lizard species on the island will have many new adaptations. B. The island will have similar flora and fauna, with the addition of a cat population. C. Some species of ground-nesting birds may have gone extinct. D. Species that were formerly preyed upon by hawks will benefit. E. The increase in nitrogenous waste from the cats will increase plant productivity.
Which of the following is an opportunistic pathogen?
A) Pneumocystis B) Legionella C) Histoplasma D) Mycoplasma E) rhinovirus