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 CO2CO_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.