bio 1108 plant reproduction exam 2

the evolution of two multicellular generations, one specialized and the other for?

-fertilization

-dispersal

land plant ancestors relied on..

water currents to disperse their gametes

first land plants were confronted with what chalhenge?

moving gametes and offspring through the air

early diverging groups of plants evolved the capacity to move their gametes through the air but..

still required water for fertilization

animals life cycle

haploid cells- meiosis-gamates- fertilization

plants life cycle

2 multicellular phases 1 haploid 1 diploid

example chara life cycle

-haploid cells

-haploid develops into alga

-sperm released in water and fertilization

-after this dipliod zygotes are rleased in water and get dispersed

-then meiosis occurs and produces haploid cells

some land plants need what to allow their sperm to swim and fertilize

moist environments

mosses and ferms have gamates that are produced

low to the ground in moist environments

if zygote develops near parent then

there will be competition for resources so if far away it overcomes this issue

difference between green alga life cycle and land plants life cycle

land plants include multicellular sporophyte generation and green alga does not.

land plant life cycle process

-multicellular gametophyte haploid

-mitosis produces haploid gametes

-fertilization produces diploid zygote

- mitosis produces multicellular sporophyte diploid

-meiosis and makes haploid spores

life cycle of a moss (bryophyte)

-haploid spores disperse

-grow into gametophytes and sperm release simulated by rain drops (haploid)

-fertilization occurs and egg (sporangium) grows directly from gametophytes body

-this produces thousands of haploid spores through meosis

gametophyte

is the haploid (n), multicellular stage in the plant life cycle that produces gametes

sporophyte

the diploid (2n), multicellular stage in the plant life cycle that produces spores through meiosis.

sporophyte is dependent on

gametophyte for water and nutrients

sporangium

structure in the sporophyte generation of plants and fungi where spores are produced and often stored before being released.

sporangia release spores in

dry conditions

sporopollenin is.. and it protects..

-is a tough, chemical substance that makes up the outer wall of spores and pollen grains in plants.

-protects spores from UV radiation and desiccation as they move through air

what is a major trend in the evolution of land plants?

decrease in size and independence of gametophyte and increase in the prominence of the sporophyte generation

The life cycle of the fern (pteriodophytes)

-haploid spores disperse and grow into gametophytes

-haploid sperm are released when moisture are present and they fertilize

-diploid sporophyte is produced and sporangia are produced on the lower surfaces of leaves

-these release haploid spores through meiosis

seed plants produce pollen which allows for

gametes to unite even in dry surfaces

The life cycle of a seed plant

-free living diploid sporophyte undergoes meiosis producing haploid spores

-spores undergo mitosis wich produces gametophytes haploid (either male develops in pollen or female develops in ovule)

-male haploid pollinizes female haploid and fertilization occurs producing a diploid zygote.

-zygote under goes mitosis producing a diploid seed

pollen cones are found.. and produce..

found in clusters near bottom of branches of the tree

-produce spores that will develop into the male gametophyte

ovulate cones are found.. and produce..

found in upper branches and produce spores that develop into female gametophytes

cycle of pine trees: pollen and ovules

-sporophyte grows female gamerophytes from spores within the ovulate cones

-male gametophytes grow from spores within pollen cones (all diploid)

- meiosis occurs and haploid spores are released from male and female makes a protective diploid layer to ovule

-male develops into pollen grain (male gametophyte) and releases pollen and pollen will fertilize with female ovule.

-fertilization occurs in ovule cone and releases diploid vseeds that will undergo germintation

when ouvlate cone enlarges and becomes woody it is refered to as a

seed cone

seed structure

inside to out: embryo-female gametophye haploid - seed coat diploid

seeds exhibiting dormancy means

delaying germination until the enviormental conditions are met and also prevents seeds from fertilizing at the same time.

seeds low metabloic activity and stored resources allow for

seeds to survive for long periods of times

large seeds disperse blank, have blank life spans, and have little to no blank

-less far

-short life spans

-no dormancy

outer two whorls, petals, and speals serve to

attract pollinators and protect the flower as it develops

what are the central two whorls and what do they produce?

-carpels and stamens

-produce ovules and pollen

explain angiosperm pollination

-pollen lands on the stigma

-through cell division of pollen a pollen tube grows through style

-pollen reaches the ovules that are located within the sporangia

the stamen of a flower consists of

anther that hold male sporangia that produce pollen

explain angiosperm ovule development

-in each sporangium one diploid cell undergoes meiosis making 4 haploid cells

-one of the haploid cells develops into a female gametophyte that fills the sporangium

angiosperm pollen development:

-in each sproangium diploid cells undergo meiosis forming haploid spores

-each haploid spore forms into a male gameophyte soursounded by a sporopollenin containing wall (this is in the anther)

flowers communicate their presence through

scent and color and reward pollinators with pollen/nectar or chemical sercretions

self-compatible

if it can fertilize itself

Self-incompatible

A plant is self-incompatible if it cannot fertilize itself

Outcrossing

Outcrossing is the process of fertilization between two different individuals

Double fertilization

two fertilization events occur in the ovule

One sperm fertilizes the egg → forms the zygote (2n).

Another sperm fertilizes the central cell (two polar nuclei) → forms the endosperm (3n)

fruits functions:

-protect immature seeds from being prayed apoun

-enhance dispersal once seeds are mature

immature fleshy fruits are.. and because

are tough and so they don't get eaten

vegetative reproduction

reproduce asexually by growing to a new location and then producing a new plant in the process

apomixis

seed formation asexually no meiosis or fertilization