11. Nitrogen fixation is
(a) using nitrogen to build molecules such as proteins and nucleic acids.
(b) converting nitrogen in the air into a form usable by plants.
(c) recycling nitrogen from organic matter in the soil.
(d) absorbing N2 from the soil.
12. The enzyme that catalyzes the conversion of atmospheric nitrogen into ammonia is
(a) catalase. (b) nitrogenase.
(c) reductase. (d) rubisco.
13. The relationship between legumes and Rhizobium is
(a) mutualistic. (b) parasitic.
(c) competitive. (d) commensalism
14. Mycorrhizae are
(a) nutrients required by plants in relatively small amounts.
(b) plants such as mistletoe that parasitize other plants.
(c) cells that control evaporation of water from leaves.
(d) associations of roots with beneficial fungi.
15. The term alternation of generations refers to a plant’s life cycle alternating between
(a) the production of haploid gametes by meiosis with the production of diploid spores by mitosis.
(b) a haploid gametophyte generation and a haploid sporophyte generation.
(c) a haploid gametophyte generation and a diploid sporophyte generation.
(d) a flower producing generation and a leaf-producing generation.
(a) works the same way in all plants.
(b) are all based on the same mechanism of transplant rejection seen in animals.
(c) maintains variation.
(d) is the rejection of a graft by a plant.
17. In angiosperms, each pollen grain produces two sperm. What do these sperm do?
(a) Each one fertilizes a separate egg cell.
(b) One fertilizes an egg and the other fertilizes the fruit.
(c) One fertilizes an egg and the other is kept in reserve.
(d) One fertilizes an egg and the other fertilizes a cell that develops into stored food.
18. What is endosperm?
(a) male reproductive cells in plants
(b) stored food in a seed
(c) cells that make up the bulk of a pollen grain
(d) the fleshy part of a fruit such as an apple or strawberry
19. The correct arrangement of the meristematic tissue of an embryo is
(a) a ring of lateral meristem surrounding apical meristem.
(b) a ring of procambium surrounding a ring of meristem surrounding a ring of protoderm.
(c) a ring of hypocotyl surrounding a ring of radicle surrounding a ring of epicotyl.
(d) a ring of protoderm surrounding a ring of ground meristem surrounding procambium.
20. The scutellum
(a) is a specialized cotyledon found in certain monocots.
(b) develops into the seed coat.
(c) presents a barrier to self-fertilization.
(d) is a specialized cotyledon found in dicots.