Chapter 24

Question 1

alteration of generations

Answer 1

a life cycle practiced by plants in which successive plant generations alternate between the diploid sporophyte condition and the haploid gametophyte condition

Question 2

angiosperm

Answer 2

a flowering seed plant whose seeds are enclosed within the tissue called fruit. Angiosperms are the most dominant and diverse of the four principal types of plants

Question 3

bryophytes

Answer 3

a plant that lacks a vascular (fluid transport) structure. Bryophytes are the most primitive of the four principal varieties of living plants

Question 4

cell wall

Answer 4

a relatively thick layer of material that forms the periphery of all plant and fungal cells and many types of bacterial, archael, and protist cells

Question 5

chloroplast

Answer 5

the organelle within plant and algae cells that is the site of photosynthesis

Question 6

deciduous

Answer 6

refers to plants that show a coordinated, seasonal loss of leaves. This strategy allows plants to conserve water during a time they could perform little photosynthesis anyway

Question 7

dormancy

Answer 7

a state in which growth is suspended and there is a prolonged low level of metabolic activity. Dormancy allows organisms to conserve energy during times of unfavorable environmental conditions

Question 8

endosperm

Answer 8

the nutrient tissue that surrounds an angiosperm embryo in the seed

Question 9

Endosperm examples

Answer 9

rice and wheat grains consist mostly of endosperm

Question 10

gametophyte generation

Answer 10

the haploid generation in plants that produces gametes (eggs and sperm). In the flowering plants (angiosperms)m this generation is microscopic but gives rise to the visible sporophyte generation

Question 11

gymnosperm

Answer 11

a seed plant whose seeds do not develop within fruit tissue. Gymnosperm reproduces through wind-aided pollination

Question 12

gravitropism

Answer 12

the bending of a plant’s roots or shoots in response to gravity. This capability helps a plant orient its roots and shoots properly -roots toward the center of the Earth, shoots away from it

Question 13

hormone

Answer 13

a substance that, when released in one part of an organism, goes on to prompt physiological activity in another part of the organism. Both plants and animals have hormones

Question 14

photoperiodism

Answer 14

the ability of a plant to respond to changes it experiences in the daily duration of darkness relative to light

Question 15

seed

Answer 15

a reproductive structure in plants that includes a plant embryo, its food supply, and a tough protective casing

Question 16

seedless vascular plant

Answer 16

a plant that has a vascular (fluid transport) structure but does not reproduce through use of seeds. One of the 4 principal varieties of plants

Question 17

sporophyte generation

Answer 17

the diploid, spore-producing plant generation. This generation is the dominant, visible generation in flowering plants

Question 18

thigmotropism

Answer 18

the growth of a plant in response to touch. This capability allows tendrils to wrap around other objects, thus helping a plant climb upward toward light