Chapter 27 - Flowering Plant Reproduction

What are the four main parts, or whorls, of a typical flower?

Sepals, petals, stamens, and carpels.

What is the function of sepals?

They protect the developing flower bud.

What is the function of petals?

They often attract pollinators with their colors, shapes, and scents.

What is the male reproductive structure of a flower?

The stamen.

What are the two parts of a stamen?

Anther and filament.

What is the function of the anther?

It produces pollen.

What is the function of the filament?

It supports the anther.

What is the female reproductive structure of a flower?

The carpel.

What are the three main parts of a carpel?

Stigma, style, and ovary.

What is the function of the stigma?

It receives pollen.

What is the function of the style?

It connects the stigma to the ovary and provides a pathway for pollen tubes.

What is the function of the ovary?

It contains ovules and may develop into a fruit after fertilization.

What is an ovule?

The structure containing the female gametophyte; it develops into a seed after fertilization.

What is a pistil?

A female flower structure made of one or more carpels.

What is a complete flower?

A flower with sepals, petals, stamens, and carpels.

What is a perfect flower?

A flower that has both male and female reproductive structures.

What is pollination?

The transfer of pollen to a receptive stigma in flowering plants.

What happens after pollen lands on a compatible stigma?

A pollen tube grows toward an ovule, carrying sperm cells.

What is double fertilization?

The process in angiosperms in which two sperm cells participate in two fertilization events.

What happens in the first fertilization event?

One sperm fuses with the egg to form a diploid zygote.

What happens in the second fertilization event?

The other sperm fuses with two polar nuclei to form triploid endosperm.

What is endosperm?

Nutritive tissue that provides food for the developing plant embryo.

What is an easy way to remember double fertilization?

One sperm helps form the embryo; the other helps form its food supply.

What does the zygote develop into?

The plant embryo.

What does an ovule become after fertilization?

A seed.

What does the ovary usually become after fertilization?

A fruit.

What are the three basic parts of a seed?

Embryo, stored food or nutritive tissue, and seed coat.

What is the seed coat?

The protective outer covering of a seed.

What is a cotyledon?

An embryonic seed leaf that may store or absorb nutrients.

How many cotyledons does a eudicot embryo have?

Two.

How many cotyledons does a monocot embryo have?

One.

What is the scutellum in a monocot seed?

The specialized cotyledon that helps absorb nutrients for the embryo.

What is the coleoptile?

A protective sheath around the emerging shoot of a grass embryo.

What is the coleorhiza?

A protective sheath around the emerging root of a grass embryo.

What is a fruit botanically?

A mature ovary, sometimes including additional flower tissues, that contains or is associated with seeds.

What is the pericarp?

The fruit wall that develops from the ovary wall.

What are the three layers of the pericarp?

Exocarp, mesocarp, and endocarp.

What is the exocarp?

The outermost layer of the fruit wall.

What is the mesocarp?

The middle layer of the fruit wall.

What is the endocarp?

The innermost layer of the fruit wall.

What is a fleshy fruit?

A fruit with a soft or juicy mature pericarp.

What is a dry fruit?

A fruit with a dry pericarp at maturity.

What is a dehiscent dry fruit?

A dry fruit that splits open at maturity to release seeds.

What is an indehiscent dry fruit?

A dry fruit that does not naturally split open at maturity.

What is a berry?

A fleshy fruit that generally has a soft pericarp and seeds within its flesh.

What is a drupe?

A fleshy fruit with a hard inner layer around the seed, as in a peach.

What is a simple fruit?

A fruit developing from one ovary of one flower.

What is an aggregate fruit?

A fruit developing from multiple ovaries of one flower.

What is a multiple fruit?

A fruit developing from the ovaries of multiple flowers in an inflorescence.

How can wind disperse seeds?

Seeds may be lightweight or have wings or hairs that help them travel in air.

How can animals disperse seeds?

Animals may eat fruits and pass seeds elsewhere, or carry seeds attached to their bodies.

How can plants disperse seeds explosively?

Fruits or seed pods split forcefully, scattering seeds away from the parent plant.

What conditions commonly support seed germination?

Enough water, a suitable temperature, and oxygen.

What is germination?

The process in which a seed resumes growth and the embryo develops into a seedling.

What is the radicle?

The embryonic root, which usually emerges first during germination.

What is the hypocotyl?

The embryonic stem region below the cotyledons.

What is one typical difference between bean and corn germination?

Bean is a eudicot with two cotyledons; corn is a monocot with one cotyledon and a protective coleoptile.

What is the main purpose of seed dispersal?

To spread offspring away from the parent plant, reducing competition and helping plants colonize new areas.