Angiosperm Reproduction and Biotechnology Flashcards

Angiosperm Reproduction

• Key Features: flowers, double fertilization, and fruits. These are three special things about angiosperms (flowering plants).

Floral Organs

• Complete flowers have all four main parts (sepals, petals, stamens, and carpels).

• Incomplete flowers are missing one or more of these parts.

• Inflorescences are groups of many flowers clustered together.

Pollination

• Pollination is when pollen moves from the anther to the stigma of a flower.

• A pollen tube then grows down to the ovary and releases two sperm cells into the embryo sac.

Double Fertilization

• One sperm cell fertilizes the egg to form the embryo. The other sperm cell combines with other nuclei to form the endosperm, which nourishes the developing plant.

Seed Development

• The ovule becomes the seed, and the ovary becomes the fruit.

• When conditions are right, the embryo in the seed grows into a new plant (sporophyte).

Pollination Methods

• Pollination happens through wind, bees, or other means.

• Coevolution is when two interacting species evolve together.

Endosperm Development

• The endosperm develops before the embryo.

• It stores food for the seedling when it starts to grow.

Embryo Development

• The basal cell creates a suspensor, which anchors the embryo.

• The terminal cell develops into most of the embryo.

• Cotyledons (seed leaves) form, and the embryo gets longer.

Seed Structure & Dormancy

• The seed coat protects the embryo and its food supply.

• Dormancy helps seeds wait for the best time to grow.

Flowering

• Flowering is timed to increase the chances of cross-pollination.

Fruit Structure & Function

• The mature ovary becomes the fruit, which protects the seeds and helps them spread.

Fruit Types

• Simple fruits come from one or more fused carpels.

• Aggregate fruits come from a single flower with many separate carpels.

• Multiple fruits come from a group of flowers (inflorescence).

Asexual Reproduction

• Fragmentation is when a piece of the parent plant breaks off and grows into a new plant.

• Apomixis is when seeds are produced asexually from a diploid cell.

Asexual vs Sexual Reproduction

• Asexual reproduction is good in stable environments, but clones are vulnerable to changes.

Mechanisms Preventing Self-Fertilization

• Dioecious species have separate male and female plants.

• Some flowers have structures that prevent self-pollination.

Self-Incompatibility

• This is a plant's ability to reject its own pollen.

Totipotency and Tissue Culture

• Totipotent cells can divide and create a clone asexually.

Vegetative Propagation & Grafting

• Vegetative propagation is when humans help plants reproduce asexually.

• Grafting is when a twig or bud is attached to a related plant.

Plant Modification

• People change crops through breeding and genetic engineering.

• Hybridization introduces new genes.

Plant Breeding

• Useful mutations are used in breeding.

Plant Biotechnology and Genetic Engineering

• Using plants to make useful products.

• Transgenic organisms have genes from other species.

Reducing World Hunger

• Genetically modified plants can improve food quality and amount.

• Some crops resist pests or tolerate herbicides.

Reducing Fossil Fuel Dependency

• Biofuels made from plants can lower CO_2 emissions.

Issues of Human Health

• Genetic engineering might introduce allergens.

Effects on Nontarget Organisms

• GM crops could harm other organisms.

Transgene Escape

• Engineered genes can escape into weeds, creating "superweeds."

• Solutions include male sterility and apomixis.