Plant Bio Lecture 15

1. anther

2. filament

3. stamen

4. stigma

5. style

6. pistil

7. ovary

8. calyx

9. sepal

10. sepals

11. ovule

12. receptacle

13. peduncle

14. petal

15. petals

16. corolla

label

anther

where is pollen produced

pistil

what is female part of the flower

stigma

where does pollen land if there is going to be pollination

ovule

what is inside the ovary in a plant

egg

what does ovule contain

seed

what does ovule mature into

beetle and hepatica

what is this an example of

beetles

what were the first pollinating insects

beetles

flies

____ attracted to pollen

_____ attracted to what they though was a dead animal

hepatica

what purple flower has sepals that look like petals

carrion fly and african milkweed

example of what

flies

smell really bad so flies lay their eggs there

what is the african milkweed pollinated by

how does it attract pollinators

inside

where are the stamens in african milkweeds

bee and rosemary

example of what

bees

who are the most important pollinators

blue/purple wavelengths + UV light

what wavelengths can bees see very well

bilateral symmetry, blues/purples, and fused parts (adnation)

what traits do you see in bee pollinated plants

honey guides on digitalis (foxglove)

example of what

head to the back of the flower to get the nectar so it gets pollen on it

how do bees pollinate this big flower

butterfly and daisy

example of what

long feeding tubes

what do butterflies and moths produce so they can reach the nectar tubes on the plants they pollinate

white flowers b/c most are nocturnal

what colors flowers are moths most attracted to? why?

hummingbird and scarlet monkey flower

example of what

red

what color flower are hummingbirds most attracted to that a lot of insects can’t see

long feeding tubes

what do hummingbirds have to reach the nectar tubes

to be worth all the energy they have to use to flap their wings

what do hummingbird pollinated plants have a lot of nectar

no, birds can’t smell so strong

do bird pollinated plants need a strong scent

bat and organ pipe cactus

example of what

at night b/c bats are nocturnal

no

when do cacti usually open their flowers? why?

are their flowers showy?

wind pollination

what kind of pollination

anthocyanins

what produces red pigments

xanthophylls

what produces yellow pigments

inside the anther

Where are microspore mother cells located?

pollen grains (male gametophytes)

What do microspores eventually develop into?

Two cells: a generative cell and a tube cell.

How many cells are in a typical mature pollen grain before the generative cell divides?

Divides to produce two sperm cells.

What is the function of the generative cell?

Inside the ovules within the ovary.

Where are megaspore mother cells located?

3

How many rounds of mitosis does the surviving megaspore undergo?

8

How many nuclei are produced after three rounds of mitosis?

One egg cell, two synergids, three antipodal cells, and a central cell containing two polar nuclei.

What structures are found in a typical mature embryo sac?

Help guide the pollen tube toward the egg.

What is the function of the synergids?

Fuse with one sperm cell during double fertilization to form the primary endosperm nucleus.

What is the function of the polar nuclei?

Help support and nourish the developing embryo sac.

What is the function of the antipodal cells?

Microsporogenesis

The process in which a diploid microspore mother cell undergoes meiosis in the anther to produce four haploid microspores, which eventually develop into pollen grains.

Vegetative (tube) cell

A cell inside a pollen grain that develops into the pollen tube, allowing the two nonmotile sperm cells to travel to the egg inside the ovule for fertilization.

Generative cell

A cell inside a pollen grain that divides to produce two sperm cells, which participate in double fertilization.

Megasporogenesis

The process in which a diploid megaspore mother cell undergoes meiosis inside the ovule to produce four haploid megaspores, typically with only one surviving to develop into the female gametophyte.

Funiculus

The stalk that attaches the ovule to the ovary wall and provides a pathway for nutrients to reach the ovule.

Micropyle

A small opening in the integuments of an ovule that allows the pollen tube to enter and deliver sperm cells for fertilization.

Chalazal

Refers to the end of the ovule opposite the micropyle, where the integuments and nucellus meet near the attachment of the funiculus.

Embryo sac

The female gametophyte of flowering plants, located inside the ovule, that typically contains 7 cells and 8 nuclei, including the egg cell involved in fertilization

Egg cell

The haploid female gamete located inside the embryo sac of an ovule that fuses with a sperm cell during fertilization to form a diploid zygote.

Polar nuclei

Two haploid nuclei located in the central cell of the embryo sac that fuse with one sperm cell during double fertilization to form the triploid endosperm nucleus.

Synergids

Two cells located next to the egg cell in the embryo sac that help guide the pollen tube toward the egg for fertilization.

Antipodals

Three cells located at the chalazal end of the embryo sac, opposite the egg cell, that help provide nutrients and support to the developing embryo sac.

Pollination

The transfer of pollen grains from the anther to the stigma of a flower, allowing fertilization to occur.

Double fertilization

A process in flowering plants where one sperm cell fertilizes the egg to form a diploid zygote (2n), while the other sperm cell fuses with the two polar nuclei to form triploid endosperm (3n), which provides nutrients to the developing embryo.

Endosperm

A nutrient-rich tissue formed during double fertilization in flowering plants that is typically triploid (3n) and provides nourishment to the developing embryo.

Zygote

A diploid (2n) cell formed when a sperm cell fertilizes an egg cell, which develops into an embryo.

Triple fusion

The fusion of one sperm cell with the two polar nuclei in the embryo sac during double fertilization, forming a triploid (3n) nucleus that develops into the endosperm.