Campbell Biology Chapter 30

aggregate flower

A fruit such as a blackberry that develops from a single flower that has several carpels.

anther

The terminal pollen sac of a stamen, inside which pollen grains with male gametes form in the flower of an angiosperm.

carpel

The female reproductive organ of a flower, consisting of the stigma, style, and ovary.

coevolution

The mutual influence on the evolution of two different species interacting with each other and reciprocally influencing each other's adaptations.

conifer

A gymnosperm whose reproductive structure is the cone. Conifers include pines, firs, redwoods, and other large trees.

cotyledons

The one (monocot) or two (dicot) seed leaves of an angiosperm embryo.

cross-pollination

The transfer of pollen from flowers of one plant to flowers of another plant of the same species.

double fertilization

A mechanism of fertilization in angiosperms, in which two sperm cells unite with two cells in the embryo sac to form the zygote and endosperm.

embryo sac

The female gametophyte of angiosperms, formed from the growth and division of the megaspore into a multicellular structure with eight haploid nuclei.

endosperm

A nutrient-rich tissue formed by the union of a sperm cell with two polar nuclei during double fertilization, which provides nourishment to the developing embryo in angiosperm seeds.

filament

The stalk of a stamen.

flower

In an angiosperm, a short stem with four sets of modified leaves, bearing structures that function in sexual reproduction.

fruit

A mature ovary of a flower that protects dormant seeds and aids in their dispersal.

Ginkgophyta

A phylum of gymnosperms represented by a single extant species, Ginkgo biloba, characterized by fanlike leaves that turn gold and are deciduous in autumn.

integuments

Layers of sporophyte tissues that contribute to the structure of an ovule of a seed plant.

megaspores

A spore from a heterosporous plant that develops into a female gametophyte bearing archegonia.

microspores

A spore from a heterosporous plant that develops into a male gametophyte with antheridia.

multiple fruit

A fruit such as pineapple that develops from an inflorescence, a group of flowers tightly clustered together. When the walls of the many ovaries start to thicken, they fuse together and become incorporated into one fruit.

ovary

(1) In flowers, the portion of a carpel in which the egg-containing ovules develop.

ovule

A structure that develops in the plant ovary and contains the female gametophyte.

pericarp

The thickened wall of a fruit.

petal

A modified leaf of a flowering plant. Petals are the often colorful parts of a flower that advertise it to insects and other pollinators.

Anthophyta

The phylum containing all angiosperms.

Coniferophyta

The largest of the four gymnosperm phyla, the reproductive structure is the cone. Conifers include pines, firs, redwoods, and other large trees.

Cycadophyta

A phylum of gymnosperms that superficially resemble palms. Cycads bear naked seeds on sporophylls, leaves specialized for reproduction.

Gnetophyta

A phylum of gymnosperms consisting of just three extant genera that are very different in appearance.

pollen grains

The structures that contain the immature male gametophytes.

pollination

The placement of pollen onto the stigma of a carpel by wind or animal carriers, a prerequisite to fertilization.

progymnosperms

An extinct group of plants that is probably ancestral to gymnosperms and angiosperms.

sepal

A whorl of modified leaves in angiosperms that encloses and protects the flower bud before it opens.

stamen

The pollen-producing male reproductive organ of a flower, consisting of an anther and filament.

stigma

(plural, stigmata) The sticky part of a flower's carpel, which traps pollen grains.

style

The stalk of a flower's carpel, with the ovary at the base and the stigma at the top.