Chapter 38: Plant Reproduction Flashcards
Flower
a reproductive shoot of the angiosperm
Flower consists of 4 whorls of highly modified leaves”
sepals, petals, stamens and carpel
receptacle
The part of a flower stalk where the parts of the flower are attached
Sepal
non-reproductive; located at the base; typically functions protect the developing floral bud
Petal
non-reproductive; often colorful and serve to attract insects or birds to disperse the plants’ pollen
Stamen
reproductive, male; consists of a filament topped by an anther with pollen sacs that produce pollen
Carpel
reproductive, female; has a long style with a
stigma on which pollen may land; base of the style is
an ovary containing one or more ovules/eggs
pistil
a single carpel or group of fused carpels
Complete flowers
contain all four floral organs
Incomplete flowers
lack one or more floral organs, for example stamens or carpels
monoecious
hermaphroditic; both male and female parts housed on one plant
dioecious
the plants house male and female flowers on separate plants
sporophyte
The multicellular diploid form that results from union of
gametes; meiosis in the sporophyte produces haploid spores that develop into gametophytes.
gametophytes
The multicellular haploid form that produces haploid
gametes by mitosis; the gamete-producing generation
Difference between sporophyte and gametophyte
Sporophyte is larger, more conspicuous, longer life span
alternation of generations
the alternation of a sexual phase and an asexual phase in the life cycle of an organism (the alternation between sporophyte and gametophyte generations)
The angiosperm life cycle includes (4 stages)
- Gametophyte development
- Pollination
- Double Fertilization
- Seed development
The haploid gametes unite and develop into…
sporophytes
Pollination
the male gametophyte (pollen grain) is transferred
from the anther to a stigma (This process is required for fertilization)
Fertilization
the fusion of gametes, occurs after the two sperm reach the female gametophyte (ovule); requires pollination first
Double fertilization
Two sperm cells unite with two cells in the female
gametophyte (embyro sac) to form the zygote and
endosperm; process specific to angiosperms
Egg > zygote
Polar nuclei > endosperm
After double fertilization, the ovule develops into the…
seed
After double fertilization, the ovary
develops into…
a fruit that encloses the seeds and aids in dispersal by wind or animals
The sporophyte embryo develops from the…
zygote
endosperm
stores nutrients that can be used by the seedling
cotyledons
help supply the nutrition a plant embryo needs to germinate and become established as a photosynthetic organism (“seed leaf”)
seed coat
encloses the embryo and its food supply
Eudicots: embryo consists of…
two cotyledons
radicle
embryonic root
Monocots: embryo consists of…
one cotyledon
dormancy
condition of extremely low metabolic rate in which growth and development have been suspended
Dormancy ______ the chances that germination will occur at a time and place most advantageous to the seedling
increases
Germination
the sprouting of a seed, spore, or other reproductive body, usually after a period of dormancy
imbibition
the uptake of water due to low water potential of the dry seed
Germination depends on _______
imbibtion
Hypocotyl
portion of the embryonic stem from roots up to the attachment site of the cotyledons
The main advantage of flowers is…
Sexual reproduction
Flowering is triggered by…
a combination of environmental cues and internal signals
The thickening of the ovary wall forms the _____ of the fruit
pericap
Simple fruits develop from….
a single or several fused carpels (Ex: pea)
Aggregate fruits develop from….
a single flower with multiple separate carpels (Ex: raspberry)
Multiple fruits develop from….
a group of flowers called an inflorescence (Ex: pineapple)
Accessory fruit develop from…
adjacent tissue exterior to the carpel (Ex: apple)
Sexual reproduction
production of offspring from female and male parents; parents provide haploid gametes that united to form the zygote; offspring are a genetic combination of parents
Asexual reproduction
production of offspring from a single parent; offspring are genetically identical to the parent
Fragmentation
body of one parent plant separates or fragments into smaller pieces, each of which is capable of independent existence
Apomixis
production of seeds without fertilization; diploid,
sporophyte cells within an ovule grow into an embryo, without forming gametes and the integuments surrounding the embryo harden to form a seed coat
Advantages of sexual reproduction
Genetic variation, adaptations, seeds are dispersed
Advantages of asexual reproduction
Genetically identical offspring will be well-suited to environment if parent is, requires less energy expenditure, larger and have
higher survival rates
