BIO TEST 3 156

still under work

Angiosperm life cycle is

haplodiplotonic (alternation of generations)

factors that can determine when a flower is produced-

light, temperature, promotive internal signals, inhibitory internal signals

vernalization

the requirement for a period of chilling of seeds or shoots before flowering can occur

floral organs are thought to evolve from

leaves

a complete flower has how many whorls

4 whorls

what are the 4 whorls required for a complete flower

calyx, corolla, androecium, and gynoecium

what are the 2 major trends in floral specialization

1) floral parts have grouped together or fused

2) floral parts lost or reduced

Reproductive organs of angiosperms differ from those of familiar vertebrate animals in two ways

1. Both male and female structures usually occur together in the same individual

2. Reproductive structures are not permanent parts of the adult sporophyte

male gametophyte formation (POLLEN)

anther contains pollen sac, inside we can observe hundreds microspore mother cells (diploid) they undergo meiosis to produce 4 haploid microspores and grow and develop into pollen grain through mitosis- tube cell - germinate down the style to connect with ovule and generative cell which divides into2 sperm cells - one fertilizes the egg and one fertilizes polar nuclei

female gametophyte formation (EMBRYO SAC)

Within each ovule, a diploid megaspore mother cell undergoes meiosis to produce four haploid megaspores. Usually only one megaspore survives- surviving megaspore undergoes 3 rounds of mitotic division making 8 cells- 3 antipodals, 2 synergids, egg cell, and 2 polar nuclei. ovule( megaspore) is ready for double fertilization

self pollination

Pollen from a flower’s anther pollinates stigma of the same flower

cross-pollination

Pollen from anther of one flower pollinates another flower’s stigma. Also termed outcrossing.

pollination

the transfer of pollen from anther(androecium) to stigma (gynoecium)

dioecious plants

Dioecious plants produce only ovules or only pollen.

Monoecious plants

Monoecious plants produce male and female flowers on the same plant, but they may mature at different times (dichogamy).

which evolutionary strategies promote outcrossing

dichogamy or self incompatibility, and separation of stamen and pistils

what is dichogamy

A biological process in which the male and female reproductive organs of a hermaphroditic organism mature at different times

which flowers do bees typically visit

blue or yellow flowers that typically have stripes or lines of dots that indicate the location of the nectaries

which flowers are moths attracted to

white flowers that are heavily scented

which flowers do birds pollinate

red, orange or yellow flowers with large amounts of nectar

wind pollinated species are

early evolved- ex oak tree, pecan tree

4 genetically regulated pathways to flowering

1) light dependent

2) temperature dependent

3) gibberellin dependent

4) (hormonal) autonomous pathway

light dependent pathway aka photoperiodic pathway-

triggers or induces flowering by changes in the proportion of light to dark in the daily 24hr cycle

short day plants

flower when daylight becomes shorter than the nighttime (chrysanthemums)

long day plants

flower when the daylight becomes longer than the nighttime (iris, clover, canna lily)

day neutral plants

flower when mature regardless of day length (roses, other landscape plants)

flower morphology:

Calyx = OUTTERMOST WHORL Consists of flattened sepals

Corolla = SECOND WHORL Consists of petals

Androecium = THIRD WHORL Collective term for all the stamens of a flower

• Stamen consists of a filament and an anther

• Anther contains microsporangia that make pollen grains

Gynoecium = INNERMOST WHORL Collective term for all carpels (female structures) of a flower

• Carpel consists of ovary, style, and stigma

• Ovules are produced in ovary

primitive flowers are which symmetry

radial symmetry

advanced flowers are which symmetry

bilaterally symmetrical

male gametophyte

pollen grains

female gametophyte

embryo sac

Bats, bird, and insects pollinate what

saguaro cacti- large white flowers that emit fragrance at night

Wind-pollinated plants often produce separate male and female flowers in order to

promote outcrossing

Seed germination is typically defined as the emergence of the

radicle

Plants like phlox, which have long, slender floral tubes that are filled with nectar, are often pollinated by

butterflies

Which of the following are required during seed germination in order to restart a plant embryo's metabolism?

oxygen, water

Unlike perennial plants, annual plants

typically do not have lateral meristems

The nucleus and the ER of eukaryotes are thought to have evolved

from infoldings of the plasma membrane

How is an eukaryote classified as a protist?

A eukaryote is classified as a protist when it cannot be classified in any other eukaryotic group.