Chapter 30 Plant Reproduction

Gametes

haploid produced by gametophyte

ovule seed ovary fruit

The ovary and zygote (fertilized ovule) develop and ripen. *The ovule forms the seed and the ovary forms the fruit. A fruit is a ripened ovary

Gymnosperms reproduction

The sperm is INSIDE pollen grains that are carried to female reproductive structures by the wind. Pollen cones -Male have scales with sporangia Gives rise to microspores which develop into pollen grains Female cones - Ovulate cones - have 2 ovules in each scale

Fertilization

The sperm travels through the pollen tube to the ovule. The sperm & egg fuse forming the zygote (fertilized egg) -this grows into the plant embryo (cells grow by mitosis)

Pollen cones

male have scales with sporagia

Flower structure male

male structure is called the stames and includes the anther which produces the pollen and is supporting stalk, the filament

Seed

an embryo packed with nutrients inside a protective coat

Heterospory

( two kinds of spores) (remember spores develop into gametophytes) - one female, one male

Four major steps in the seed plant cycle

1. Heterospory ( two kinds of spores) (remember spores develop into gametophytes) - one female, one male 2. plant spores are not dispersed - Female gametophytes: remain in plant and produce EGG. Stay protected Males gametophytes inside pollen grains: released from plant and carried by wind or animals (i.e. bees) to female gametophyte. No aquatic environment needed!! 3. pollination - transport of pollen from sporangium to the ovule via air or animals (cross fertilization) 4. Maturation of ovule into seed enclosing embryo and nutrients

Fern Life cycle Answer

Gametes produced in antheridium and archegonion of gametophyte Sperm swims to reach egg Fertilization produces sporophyte Haploid spores produced under leaf Release spores and develops into gametophyte

Pollen production

Microspores develop into pollen grains, which contain the male gametophytes Pollination - transfer of pollen to the part of a seed plant containing the ovules Wind dispersal If a pollen grain germinates, it gives rise to a pollen tube that discharges sperm into the female gametophyte within the ovule

Ovules Production

Ovules consist of: Megasporangium Megaspore Integument (protects)

Evolutionary trends

Reduction in size of gametophyte Notice in moss Fern Seeded plants Physical and physiological dependence on sporophyte/gametophyte is reversed

Advantages of heterospory male gametphyte

The male gametophyte (n) is dispersed in seed plants, but is protected by a layer of sporophyte tissue (2n). The whole structure is called a pollen grain.

Flower structure Female

Within the flower is called the carpel and is made up of the pistil which has an enclosed chamber called the ovary at its ase containing one or more ovules which eggs develop a stalk(style) extending from ovary ans a sticky tip the stigma

Advantages of Seeds

Withstand harsh environmental conditions - nice little package Seeds can be dormant for long time Seeds have stored food for embryo

Seeded Vascular plants

bring femals and male gametes together when conditions are dry

Broad leaved

capture more sunlight for photosynthesis

Sporophyte

diploid organism - produce spores Spores protected in the sporangia (organ) Sporocytes (cells in the sporangia) undergo meiosis and produce the spores

Fruits

encourage seed dispersal by passing through animals digestive tract and once excreted, find suitable location for germination

Archegonium

female gametophyte

Gametophyte

haploid organism - produces gametes gametes produced in gametangia (organs - 2 kinds) sperm in antheridium eggs in archegonium zygote develops in archegonium

Antheridium

male gametophyte

Cones

production of spores gametophyte grows, gametes produced gertilization happens

Flowers

reproductive shoots specialized for the transfer and receipt of pollen

Pollination

transfer of pollen to the part of a seed plant containing the ovules