Bio Ch 27 Flashcards
(43 cards)
Flower
reproductive structure of angiosperms; produces 2 types of spores by meiosis, microspores and megaspores
Microspore
undergoes mitosis and becomes a pollen grain, which is either windblown or carried by an animal to the vicinity of the female gametophyte
Megaspore
undergoes mitosis and becomes the female gametophyte
Seed
ovule becomes this; contains the embryo and stored food surrounded by a seed coat
Sepals
most leaflike of all the flower parts; usually green; protect the bud as the flower develops within
Calyx
collective name for sepals
Petals
open flower has a whorl of these; color accounts for attractiveness; size/shape/color are attractive to a specific pollinator
Corolla
collective name for the petals
Stamens
male portion of the flower; 2 parts = filament and anther
Carpel
vaselike structure that represents the female portion of the flower; 3 parts = style, stigma, ovary
Style
slender stalk that supports the stigma
Stigma
enlarged sticky knob
Ovary
enlarged base that encloses 1 or more ovaries
Gametophytes
in all land plants, the sporophyte produces haploid spores by meiosis; the spores grow and develop into haploid these, which produce gametes by mitotic division
Pollen grain
in seed plants, structure that is derived from a microspore and develops into a male gametophyte
Embryo sac
female gametophyte; consists of 7 cells - 1 egg associated with 2 synergid cells, 1 central cell with 2 polar nuclei and 3 antipodal cells
Pollination
transfer of pollen from an anther to the stigma of a carpel
Double fertilization
when the pollen tube reaches the micropyle, this occurs; one of the sperm unites with the egg to form a 2n zygote; 2nd sperm unites with the 2 polar nuclei centrally placed in the embryo sac to form a 3n endosperm nucleus
Endosperm
nutritive tissue that the developing embryonic sporophyte will use as an energy source
Coevolution
as one species changes, the other species undergoes adaptation in response, so that in the end, the 2 species are suited to one another
Development
programmed series of stages from a simple to a more complex form
Differentiation
specialization of structure and function; occurs as development proceeds
Cotyledons
seed leaves; embryo is heart shaped when these appear because of local, rapid cell division
Fruit
in botany, a mature ovary that can also contain other flower parts, such as the receptacle; protect and help disperse seeds