Reproduction in Flowering Plants Flashcards

Flashcards for Reproduction in Flowering Plants

Sepals

Green and look like leaves, protect the flower bud as it develops.

Petals

Often brightly colored, attract pollinators to the flower.

Carpel

The female part of the flower; the innermost part of a flower that produces and protects female gametophytes

Ovary

Wide base of the carpel that contains one or more ovules.

Ovules

Female gametophytes grow inside these

Style

Thin stalk of the carpel.

Stigma

Sticky or feathery area at the top of the style, specialized to capture pollen.

Stamen

Male parts of a flower.

Filament

Stalk of the stamen.

Anthers

Located at the tips of filaments, produce pollen grains.

Pollen grains

Male gametophyte; produced in anther.

pistil

Biologists sometimes call a single carpel or several carpels that are fused together a

Pollination

The transfer of pollen to the stigma of the flower.

Fruits

A structure that surrounds and protect seeds. Develop from ovary walls of flowers after fertilization

Dormancy

A period when the embryo is alive but not growing. Allows seeds to wait for favorable growth conditions.

Germination

When the plant embryo grows again. Environmental factors such as temperature and moisture can cause.

Cotyledons

Also known as seed leaves, they store nutrients that are used by the growing plant

Hormones

Chemical signals that regulate growth, activity, and development.

Target Cells

Cells affected by a hormone, containing receptors for the hormone

Receptors

Usually proteins to which hormones bind.

Apical Dominance

Inhibit growth of other buds closer to the tip of the stem; removing the apical bud removes inhibition, encouraging bushy growth.

Auxins

Control cell elongation and the growth of new roots.

Cytokinins

Stimulate cell division. Work with auxins to heal injured plants and balance root and shoot growth.

Gibberellins

Promote overall plant growth, especially in stems and fruits. Stimulate germination of seeds.

Abscisic Acid

Inhibits cell division, stopping growth. Regulates seed dormancy.

Ethylene

A gaseous hormone that ripens fruits. Causes plants to drop unnecessary organs

Tropisms

Growth responses of plants to environmental stimuli such as light, gravity, and touch

Positive Tropism

Move toward stimuli

Negative Tropism

Move away from stimuli

Phototropism

The tendency of a plant to grow toward a light source

Positive Phototropism

Growth toward the light (e.g., shoots).

Negative Phototropism

Growth away from the light (rare, but some roots may exhibit this in specific cases).

Gravitropism

A plant's growth response to gravity is also influenced by auxins.

Positive Gravitropism

Growth in the direction of gravity (e.g., roots grow downward).

Negative Gravitropism

Growth against gravity (e.g., stems grow upward).

Thigmotropism

A plant's growth response to touch or physical contact.

Positive Thigmotropism

Growth toward the touch stimulus (e.g., tendrils coiling around supports).

Negative Thigmotropism

Growth away from the touch stimulus (e.g., roots avoiding barriers in the soil).

Photoperiod

The response of plants to the relative lengths of light and darkness in a day, guiding seasonal activities like flowering and growth.

Phytochrome

A pigment that absorbs red light, initiating signals within plant cells to regulate flowering and growth.

Short-Day Plants

Flower when nights are long and days are short (e.g., chrysanthemums).

Long-Day Plants

Flower when nights are short and days are long (e.g., spinach, irises).

Winter Dormancy

A period of inactivity in plants during winter, controlled by phytochrome, helping them survive colder conditions.