Plant Reproduction Flashcards
Apomixis
Clone of mother plant
Seeds, but no sperm
4 flower organs
Sepal
Petal
Stamen
Carpel
Sepal
Photosynthesis
Protection of unopened floral bud
Growing plant: green bud covering enclosing unopened flower
Petal
Brightly colored
Attract pollinators
Carpel
Female reproductive system of plant
Stigma, style, ovary
Ovary
Base of carpel Contains ovule (houses embryo sac)
Style
Neck of carpel
Connects stigma with ovary
Stigma
Top of carpel
Sticky: captures pollen
Receptacle
Attaches floral organs to stem
Stamen
Male reproductive system of plant
Filament and anther
Anther
Pollen-containing portion of stamen
Top of stamen
Filament
Stalk of stamen
Perfect
Containing both male and female parts
Complete
Containing all 4 floral organs
Dioecious species
Either male or female flower on 1 plant
Monoecious
Both male and female flowers on 1 plant
Thrum and pin flowers
Thrum: stamens are above styles
Pin: styles are above stamens
Outcrossing: thrums are good at pollinating pins and vice versa
Angiosperm life cycle
Pollen (n) from anther sticks to stigma Pollen releases sperm (n), which travel down to egg Sperm fertilizes egg Zygote (2n) becomes embryo (2n) (seed) Seed germinates Mature sporophyte plant (2n) grows
Development of male gametophyte
Microsporophyll (2n): stamen -> Microsporangia (2n): pollen sac -> Microsporocyte (2n) -> Meiosis -> 4 microspores (n): pollen tetrad -> Mitosis -> Microgametophyte (n): pollen grain (has nucleus and generative cell that forms 2 sperm)
Development of female gametophyte
Megasporophyll (2n): carpel ->
Megasporangia (2n): ovule ->
Megasporocyte (2n): female spore/”mother cell” ->
Meiosis ->
Megaspores (n): 3 out of 4 degenerate ->
Mitosis ->
Megagametophyte (n): embryo sac w/egg
Contents of megagametophyte
3 antipodal cells (opposite end of sac as egg)
2 polar nuclei (middle of sac)
1 egg
2 synergids (surround egg)
Pollinators
Many different varieties: moths and butterflies, flies, bats, birds, bees, etc.
Reason why there are so many different species of angiosperms
Double fertilization
2 sperm are released by pollen grain
1 fuses with egg, creating zygote (2n)
Other fuses with 2 polar nuclei, creating endosperm (3n)
Endosperm
Storage structure for growing plant
Cotyledons
Seed leaves on embryo
Monocot: 1
Dicot: 2
Development of embryo
Zygote -> basal cell and terminal cell -> terminal cell turns into proembryo and basal cell produces suspensor (umbilical cord) -> proembryo develops cotyledons, shoot apex, root apex, and seed coat
Simple fruit
Develops from single carpel or several fused carpels of 1 flower
Example: pea
Aggregate fruit
Develops from many separate carpels of 1 flower
Example: raspberry
Multiple fruit
Develops from many carpels of the many flowers that form as an inflorescence
Example: pineapple
Accessory fruit
Develops largely from tissues other than ovary
Example: apple (ovary=core; receptacle=part we eat)
Fruit and seed dispersal
Wind: dandelion seeds, tumbleweeds, winged fruit of maple
Water: coconut seed inside buoyant husk
Animal: squirrel burying seeds, seeds dispersed in black bear feces, ant carrying seed to nest
Eudicot seed
Example: bean
2 seed leaves (cotyledons): storage and covering of developing leaf
Seed coat covers seed
Radicle (in bent part of bean): embryonic root
Monocot seed
Example: corn 1 seed leaf (cotyledon): developing leaf Coleoptile: covers young shoot Coleorhiza: covers young root Endosperm: food storage
