plant reproduction Flashcards
what is a heterosporous?
plant produce 2 types of spores which develop into 4 types of gametophytes
what is endosporous development?
in many heterosporous plants, gametophytes produce by spores develop inside spore wall
increase in fertilization and increase in survival success
what is whorl 1?
the sepals
function is to protect the diploid
outer most later
what is whorl 2?
petals
attracts insects that can see in that colour spectrum
attracts pollinators
how many petals does a monocot have?
3
what is whorl 1 and 2 called and why?
called the perianth
vegetative, no roll in reproduction
what is whorl 3?
stamens (male reproductive parts)
gametophyte tissue
what is an anther?
when matured, gametophyte expressed to be picked up by wind or pollinator
what is whorl 4?
carpel (female reproductive parts)
stigma, style, ovary
what is the stigma?
highly controlled by plant
pollen must land on it to be fertilized
can be made hospitable to pollen
plant can choose if it accepts the pollen or not
what is the style?
pollen moves down and deposited into the body
how many eggs can the ovary have?
1 - 100s of eggs
where are the eggs housed in the ovary?
in the ovules
what is a perfect flower?
has both stamens and carpels on same flower
high change of self fertilization, therefore high change of inbreeding
what is an imperfect flower?
stamens or carpels, not both
more rare than perfect flowers
what is dichogamy?
sequential hermaphroditism in a perfect flower
separation in time of maturation and fertilization to decrease inbreeding
what is protandry?
male phase comes before the female phase
what is protogyny?
female phase comes before the male phase
what are monoecious plant?
male flowers and female flowers in same plant
what is a dioecious plant?
some plants with only staminate flowers, some with only pistilate flowers
quality over quantity
more morpho genetically diverse
less chance of fertilization
what is approach herkogamy (pin)?
stigmas are above the anthers
less chance of self fertilization
what is reverse herkogamy (thrum)?
stigmas are below the anthers
high chance of self fertilization
pollen grains
meiosis produces haploid microspores than goes to produce a pollen grain
one cell develops into two sperm cells
other cell produces pollen tube
ovules
form inside carpel, on wall of ovary
micropyle opening at one end
meiosis produces 4 haploid megaspores
undergoes 3 mitosis without cytokinesis producing 8 nuclei in a single large cell
what is a female gametophyte?
egg cell
2 synergids, role in pollination
2 polar nuclei, give rise to endosperm
what is self-incompatibility?
some plants are selective to who fertilizes
will see of male gametophyte has same phenotype
if have different phenotype, will bring in to fertilize egg
what is double fertilization?
one sperm nucleus fuses with one egg nucleus to form a diploid zygote
other sperm nucleus fuses with the central cell to form triploid endosperm tissue
what are the adaptive benefits of double fertilization?
helps signal mother plant to say egg has been fertilized successfully
difference in genetic diversity
seed
mature ovule encased by protective seed coat (Testa)
embryo has lengthwise exit
structure forms when ovule matures after sperm fertilization through pollination
seeds are major adaptation for uncertain environments
fruits
matured or ripened ovary
protects seeds
helps disperse seeds by animals, wind or water
fruit wall (pericarp) develops from ovary wall
what is germination?
reactivation of metabolically inert embryo
does this by access to water
eudicot embryos
2 cotyledons (seed leaves)
embryonic shoot
- upper epicotyl and lower hypocotyl
embryonic root
- radicle
monocot embryos
single cotyledon
- scutellum absorbs nutrients from endosperm
coleoptile
- protects shoot apical meristem and first leaves
coleorhiza
- protects radicle
what are the different modes of germination?
epigeal
hypogeal
what is epigeal germination?
the cotyledon grows out of ground
faster growth
good nutrient rich soil
what is a hypogeal?
cotyledon is kept underground
nutrient poor environment
slower growth
what is vegetative reproduction?
parts of body can be broken off and planted and grown new plant
