Chapter 38 and friends Flashcards
relationship between was Campsoscolia and orchid
parasitic
angiosperms
flowering plants
in plants, type of cell dividsion that produces gametes
mitosis
in animals, gametes are produced by meiosis
alteration of generations
multicellular haploid and diploid generations take turns producing each other
sporophyte (2N) -> (meiosis) spores (N) -> (growth and mitosis) gametophyte (N) -> (Mitosis) Gametes ->Fertilization and growth -> sporophyte (2N)
anther
end of the stamen
has sacs within it that produce pollen
4 components of a complete flower
structure and function
sepals - reprodcutive (male), enclose and protect unopened floral buds, more leafy in appearance
petals - sterile, most brightly colored (advertise)
stamens - sterile
carpels - reproductive (female, has ovary (ovules), stulye,stigma (capture pollen) - pistil (collective term)
all attached to receptacle
male gametophyte
origin and structure
pollen grain - consists of 2 haploid cells
generative cell
tube cell - pollen tube, delivers sperm to female gametophyte
and spore wall
pollen grain develops within the microsporangia (pollen sacs) of anthers at the tips of the stamens
microsporocyte (2N) -> (meiosis) 4 microspores (n) -> (Mitosis) 4 pollen grains (N)
male gametophyte develops inside anther
female gametophyte
origin and structure
embryo sac
ovule becomes seed
develops in ovule (megasporangium)
megasporocyte (2N) -> (meiosis) 1 megaspore (really 4, but only 1 survives) -> (mitosis) embryo sac
Pollination
transfer of pollen from an anther to a stigma
wind, water, animals
occurs when pollen grain lands on stigma and germinates.
fate of each of the two sperm within a mature male gametophyte and how the sperm reach the ovule
one sperm fertilizes the egg, forming the zygote
the other sperm combines with the 2 polar nuclei of the embryo sac’s large central cell, forming a triploid cell that develops into the nutritive tissue called endosperm
the sperm reach the ovule by traveling down the pollen tube that forms when the pollen is germinated
mature ovule
seed
how does the endosperm end up with 3 sets of chromosomes and function
a sperm combines with 2 polar nuclei
food-stroing tissue of seed
how do cotyledons develop and function
as bumps on the proembryo
absorb and store food from the endosperm
part of flower develops into fruit
and function
the ovary
seed dsipersal, a part of it is edible and it entices an animal
function of seed dormancy. first step in the germination of the seed
it increases advantageous conditions for the seed to germinate
imbibition - uptake of water due to the low water potential of the dry seed
two regions of undifferentiated tissue in plant
meristematic tissue (=to animal stem cells) (found in the Apical Meristem (tissue at top of plant covered by leaves) and lateral mersitem)
horizontal stems (stolons (runners) on top, rhizomes, underground) -this can produce large clones
asexual (vegetative) reproduction
fragmentation
type of asexual reproduction
plant breaking apart at specific places
Examples of alteration of generations (moss, ferns, angiosperms)
moss - gametophyte is most conspicuous stage (what you see)
ferns and angiosperms - sporophyte (2n) is more conspicuous, gametophyte is at base, gametophyte stage is very reduced
monoecious
diocecious
parts of plant can be male or female
entire plant is male or female
Fertilization in angiosperms
- generative cell (haploid) within pollen grain divides by mitosis (2 sperm)
- pollen tube grows, carrying 2 sperm
- double feritilization
if the egg is fertilized, the ovule develops into seed and ovary into fruit.