Flowers and Reproduction Flashcards
Advantage of sexual reproduction
produces genetic variation in the offspring
Parts of pistil
- stigma
- style
- ovary
Parts of stamen
- anther
- filament
The stalk of a flower
Pedicel
stalk of the whole inflorescence
Peduncle
The part of a flower stalk where the parts of the flower are attached.
Receptacle
The outer parts of the flower (often green and leaf-like) that enclose a developing bud.
Sepal
The parts of a flower that are often conspicuously colored.
Petal
The pollen producing part of a flower, usually with a slender filament supporting the anther.
Stamen
The part of the stamen where pollen is produced.
Anther
The ovule producing part of a flower. The ovary often supports a long style, topped by a stigma. The mature ovary is a fruit, and the mature ovule is a seed.
Pistil
The part of the pistil where pollen germinates.
Stigma
The enlarged basal portion of the pistil where ovules are produced.
Ovary
Pollen grains
- microspore
- microspore nucleus (haploid)
Ovule
- megaspore
- megaspore nucleus (haploid)
where does meiosis of microsporocyte happen
stamen
where does meiosis of megasporocyte happen
carpels
what is produced after the meiosis of microsporocytes
4 microspores
what is produced after the meiosis of megasporocytes
- 1 megaspore
- 3 small, dead cells
what is produced after the mitosis of the 4 microspores
- vegetative cell
- generative cell
what is formed after the growth of the vegetative cell
pollen tube
what is produced after mitosis of the generative cell
2 sperm cells
what is produced after the mitosis of the megaspore
8 nuclei in 1 cell
how many mitotic divisions does the megaspore undergo
3
8 nuclei in 1 cell
- 3 antipodal cells (haploid)
- 2 polar nuclei in central cell (each is haploid)
- 2 synergid cells (haploid)
- 1 egg cell (haploid)
egg apparatus
- 2 synergid cells
- 1 egg cell
- an essential constituent of seeds in flowering plants
- It originates from a fertilization event parallel to the fertilization that gives rise to the embryo
endosperm
- seed leaf within the embryo of a seed
- help supply the nutrition a plant embryo needs to germinate and become established as a photosynthetic organism and may themselves be a source of nutritional reserves or may aid the embryo in metabolizing nutrition stored elsewhere in the seed
Cotyledons
generates leaf, stem and floral structures throughout the plant’s lifetime
shoot apical meristem
the part of the stem of an embryo plant beneath the stalks of the seed leaves or cotyledons and directly above the root.
hypocotyl
the part of a plant embryo that develops into the primary root.
radicle
a terminally differentiated embryonic region that connects the embryo to surrounding tissues during early seed development
suspensor
where are seeds from?
ovule
where are fruits from?
ovary
seed
- endosperm
- embryo
- seed coat
pericarp
- endocarp
- mesocarp
- exocarp
Modifications in Flowers
- Complete flowers
- Incomplete flowers
have all four organs
complete flowers
lacks one or more of the four organs
incomplete flowers
what are the four organs of the flower
- sepals
- petals
- stamens
- pistils
example of complete flowers
- morning glory
- tiger lily
example of incomplete flowers
- squash
- corn
Modification in flowers (in terms of stamens and pistils)
- Perfect flowers
- Imperfect flowers
have both stamens and pistils
perfect flowers
either have a functioning stamen or pistil, but not both
imperfect flowers
example of perfect flowers
lily
example of imperfect flowers
- cucumber
- squash
Three ovary position
- hypogynous flower
- perigynous flower
- epigynous flower
flower with an ovary attached to the receptacle above the attachment of other floral parts
hypogynous flower
thalamus forms a cup-shaped structure around the ovary, and sepals, petals and stamens appear to be inserted on the rim of the cup
perigynous flowers
the ovary is inferior, and the petals, sepals, and stamens appear to arise from the top of the ovary
epigynous flowers
somatic helper tissue neighboring microsporocytes and supporting gametogenesis
tapetum
diploid cells capable of undergoing meiosis to form a tetrad (four joined cells) of haploid microspores.
microsporocytes
provides protection to the ovules that contain the egg — the female gametes
ovary wall
the surface of the carpel (highly modified leaf) to which the ovules (potential seeds) are attached.
placenta
organ that forms the seeds of flowering plants
ovule
stalk that attaches an ovule to the placenta
funiculus
the outer layer(s) of the ovule and develop into a seed coat as the ovule matures following fertilization
integuments
- a small opening that is found in the ovule, just close to the hilum and is retained in the seed after fertilization
- `seeds absorb water mainly through it when soaked
- helps in respiration and in the exchange of gases
micropyle
- the mass of parenchymatous tissue which is surrounded by the integumentary layers in an ovule
- the central part of an ovule that encloses the embryo sac i.e., the female gametophyte
Nucellus
A diploid cell that undergoes meiosis to produce megaspores as part of megasporogenesis
megasporocyte
Two basic arrangements of inflorescence
- determinate inflorescence
- indeterminate inflorescence
a cluster of flowers on a branch or a system of branches
inflorescence
the youngest flowers are at the top of an elongated axis or on the center of a truncated axis
indeterminate inflorescences
example of indeterminate inflorescence
raceme
the youngest flowers are at the bottom of an elongated axis or on the outside of a truncated axis
determinate inflorescences
example of determinate inflorescence
cyme
Flowers on a main stem; bottom florets open first
Spike
Modified spike with flowers attached with tiny stems
Raceme
A flower spike with repeated branching. It can be made up of corymbs, umbels, racemes, or spikes
Panicle
- many-flowered inflorescence with an indeterminate central axis and many opposite, lateral dichasia
- mixed inflorescence, with determinate and indeterminate shoots.
Thyrse
- type of racemose inflorescence with indefinite growth of the main axis
- main axis is unbranched and drooping
- bears sessile flowers close to the peduncle in an acropetal manner.
Catkin
- type of simple racemose inflorescence
- a modification of catkin in which the peduncle (primary stalk of the inflorescence) is thick and fleshy and is called spike
Spadix
Small stems arranged along the main stem. Outer florets have longer stems than inner florets giving the display a “flat” top
Corymb
Similar look as a corymb, however the small stems are attached to the main flower stem at a single point. The outer florets open first
Umbel
- A daisy-like flower composed of ray flowers around the edge and disc flowers in the center of the flat head
- The disc flowers produce the seeds: sunflowers, asters
- On some examples, the ray flowers and disc flowers look similar
Capitulum
Types of raceme inflorescence
- simple (alternate)
- simple (opposite)
- compound (double)
Types of corymb inflorescence
- simple
- compound
Types of umbel inflorescence
- simple (round)
- simple (flat)
- compound (triple)
a cyme with only a single lateral branch
monochasium
helicoid cyme with branching on the same side often leading it to curl
bostryx
scorpioid cyme with alternate branching in a spiral-like pattern
cincinnus
scorpioid cyme with alternate branching in a zig-zag pattern
rhipidium
a simple cyme in which the main axis divides into two lateral branches
dichasium
a branched dichasium
compound dichasium
a determinate thyrse
compound cyme
assist with fertilization by being the location where pollen tubes travel to deliver sperm cells to the egg
style
- serves as a vehicle that delivers male gametes (sperm cells) to a female gametophyte during double fertilization, which eventually leads to the seed formation
- one of the fastest elongating structures in plants.
Pollen tube
an oval structure present in the ovule of flowering plants
embryo sac
- thickened part in the stem of the flower
- also known as the receptacle or torus
- located at the stalk of the flower and contains distinct nodes and internodes
- supplies nutrients to the flower
Thalamus
fruit wall
pericarp
Types of fruit
- simple fruit
- aggregate fruit
- multiple fruit
develops from one single ovary
simple fruit
example of simple fruit
- apple
- peach
- tomato
- fruit in which there is one flower, but many ovaries
- carpels of flowers not fused, but grow together during fruit maturation
aggregate fruit
example of aggregate fruit
- blackberries
- raspberries
- also called collective fruits
- fruits that formed from more than one flower, which is commonly called inflorescence
Multiple fruits
example of multiple fruit
- pineapple
- mulberry
Three categories of fruits
- Fleshy fruits
- Dry fruits
- Compound fruits
Fleshy fruits
- berry
- pome
- drupe
- pepo
- hesperidium
a fleshy fruit in which all three layers- endocarp, mesocarp, exocarp- are soft
berry
example of berries
- grape
- tomato
similar to berry except that the endocarp is papery or leathery
pome
example of pome
apple
similar to a berry except that the endocarp is hard, sclerenchymatous
drupe
example of drupes
- peach
- cherry
- plum
- apricot
- fleshy fruit in which the exocarp is a tough, hard rind
- inner soft tissues may not be differentiated into two distinct layers
pepo
example of pepo
- pumpkin
- squash
- cantelope
exocarp is leathery
hesperidium
example of hesperidium
citrus fruits
Dry fruits
- indehiscent fruits
- dehiscent fruits
the pericarp splits open at maturity and releases the seeds
dehiscent fruits
the pericarp remains intact when the fruit is shed from the plant
indehiscent fruits
Indehiscent fruits
- Developing from a single carpel
- Developing from a compound gynoecium (compound pistil)
Indehiscent fruits:
Developing from a single carpel
- caryopsis
- achene
- samara
- simple and small
- containing only one seed
- the testa (seed coat) becomes fused to the fruit wall during maturation
caryopsis
example of caryopsis
- wheat
- corn
- oats
- like a caryopsis, but the seed and fruit remain distinct
- fruit wall is thin and papery
achene
example of achene
sunflowers
one-seeded fruit with winglike outgrowths of the ovary wall
samara
example of samara
- maples
- alder
- ash
Indehiscent fruits:
Developing from a compound gynoecium (compound pistil)
Nut
- although the gynoecium originally consists of several carpels and ovules, all but one ovule degenerate during development
- pericarp is hard at maturity
nut
example of nut
walnut
Dehiscent fruits
- Developing from a single carpel
- Developing from a compound gynoecium
Dehiscent fruits:
Developing from a single carpel
- Legume
- Follicle
fruit breaks open along both sides
legume
example of legumes
- beans
- peas
fruit breaks open on only one side
follicle
example of follicle
- columbine
- milkweeds
Dehiscent fruits:
Developing from a compound gynoecium
- capsule
- schizocarp
opens many ways
capsule
capsule:
splitting along lines of fusion
hyperium
capsule:
splitting between lines of fusion
iris
capsule:
splitting into a top and bottom half
primrose
capsule:
opening by small pores
poppy
compound ovary breaks into individual carpels called mericarps
schizocarp
Agents of Dispersal:
Animals
zoochory
Agents of Dispersal:
attached to animal
epizoochory
Agents of Dispersal:
eaten by animal
endozoochory
Agents of Dispersal:
birds
ornithochory
Agents of Dispersal:
mammals
mammaliochory
Agents of Dispersal:
bats
chiropterochory
Agents of Dispersal:
ants
myrmecochory
Agents of Dispersal:
wind
anemochory
Agents of Dispersal:
water
hydrochory
Agents of Dispersal:
dispersed by the plant itself
autochory
Compound fruits
- Aggregate fruits
- Multiple fruits
