Angiosperm Evolution, Reproduction, and Coevolution

Comprehensive vocabulary flashcards covering angiosperm evolution, reproductive structures, plant secondary metabolites, and pollination coevolution based on lecture notes.

Angiosperms

A species-rich group of modern seed plants (~300,000 species) characterized by flowers, fruits, wide xylem vessels, double fertilization, and seeds enclosed within fruits.

Autoploidy

A form of polyploidy resulting from nondisjunction that produces extra chromosomes in gametes within a single species.

Alloploidy

A form of polyploidy resulting from hybridization between two species with different chromosome counts, followed by whole genome duplication.

Horizontal Gene Transfer

The transfer of genetic material between different plant species, such as obtaining mitochondrial genes via viral, pathogenic, or parasitic interactions.

Secondary Metabolites

Molecules synthesized by plants that are not essential for cell structure and growth, but serve roles in defense, protection, or attracting pollinators.

Terpenes and Terpenoids

A class of plant secondary metabolites with distinct aromas and insect-repellent properties; examples include citronella, rubber, rosin, and amber.

Phenolics

A class of plant secondary metabolites including flavonoids that provide flower and fruit colors, prevent UV damage, and supply flavors like cinnamon, nutmeg, ginger, clove, and chillies.

Alkaloids

Nitrogen-containing secondary metabolites that act as toxic deterrents against herbivores or pathogens by exerting potent effects on animal nervous systems (e.g., caffeine, nicotine, morphine, cocaine, ephedrine).

Sepals

The green, outer leaf-like organs of a flower that enclose and protect the floral bud.

Petals

Flower organs that are frequently brightly colored to attract specific pollinators.

Stamen

The male reproductive organ of a flower, consisting of an anther and a supporting filament.

Anther

The sac-like structure at the top of a stamen where pollen grains are produced.

Filament

The elongated, slender stalk that supports the anther in a flower stamen.

Carpel

The female reproductive unit of a flower that encloses and produces ovules.

Pistil

The female structure of a flower composed of one carpel or multiple fused carpels.

Perianth

The outer, non-reproductive floral envelope consisting collectively of the petals and sepals.

Stigma

The top portion of the pistil that receives and recognizes pollen, permitting only appropriate pollen to germinate.

Style

The elongated middle portion of the pistil through which the pollen tube grows to deliver sperm cells to the ovule.

Ovary

The enlarged base of the pistil that encloses and protects ovules and matures into a fruit after fertilization.

Pedicel

The tip of the flower stalk directly underlying the flower.

Receptacle

The expanded tip of a floral stem that supports the flower organs.

Complete Flower

A flower containing all four standard floral organs: sepals, petals, stamens, and a pistil.

Incomplete Flower

A flower that lacks one or more of the four primary floral structures (sepals, petals, stamens, or pistil).

Perfect Flower

A flower possessing both functional male (stamens) and female (pistil) reproductive structures.

Imperfect Flower

A flower missing either male reproductive parts (stamens) or female reproductive parts (pistil).

Inflorescence

A cluster of multiple individual flowers arranged together on a single plant stem.

Coevolution

The process by which two or more species reciprocal influence each other's evolutionary pathways.

Pollinator Constancy

The behavioral tendency of pollinators (also known as fidelity) to learn specific flower characteristics and visit those flowers preferentially.

Pollination Syndrome

A combination of flower traits that evolved in response to natural selection exerted by specific abiotic or biotic pollen vectors.

Domestication Syndrome

The set of artificial selection traits favored by humans in crop plants, such as the loss of fruit shattering to improve harvest efficiency.

Shattering

The process by which wild plant fruits naturally break apart to disperse their seeds.