Angiosperm Sexual Reproduction: Life Cycle, Gametophytes, and Seed Dispersal

Diploid (2n)

A cell or organism that has paired chromosomes, one from each parent.

Haploid (n)

A cell or organism that contains a single set of chromosomes.

Microspore

A haploid spore that develops into a pollen grain.

Pollen Grain

A structure that initially consists of two cells, one of which will produce a pollen tube.

Sperm

The smaller cell that divides to become two sperm nuclei.

Megaspore

A haploid spore that develops into an embryo sac, with only one surviving from four produced.

Embryo Sac

A seven-celled structure developed from a megaspore containing a single egg cell.

Eight-Nucleate, Seven-Cell Female Gametophyte

A structure formed from the fusion of haploid cells, resulting in a seven-celled structure.

Fertilization

The process where one sperm nucleus fertilizes the egg cell to form a diploid zygote.

Zygote

A diploid cell formed from the fertilization of an egg cell by a sperm nucleus.

Endosperm

A triploid cell formed when the other sperm nucleus fuses with the central cell's two nuclei.

Seed

A plant embryo together with its stored food, surrounded by a seed coat.

Fruit

A structure that protects seeds and promotes seed dispersal.

Seed Dispersal

The mechanism by which seeds are spread away from the parent plant.

Biotic Dispersal Agents

Living organisms that assist in the dispersal of seeds, such as animals.

Abiotic Dispersal Agents

Non-living factors that assist in the dispersal of seeds, such as water and wind.

Dandelion

An example of a plant that uses wind as a mechanism for seed dispersal.

Maple Fruit

An example of a plant that uses wind as a mechanism for seed dispersal.

Tumbleweeds

An example of a plant that uses wind as a mechanism for seed dispersal.

Ants

An example of a biotic dispersal agent that helps in seed dispersal.

Sporophytes

These (2n) produce haploid spores by meiosis. The spores develop into pollen grains and embryo sacs.

Gametophytes

What produce the egg cells and the sperm cells?