Plant Biology and Evolution Flashcards

Comprehensive vocabulary flashcards covering plant biology, structure, reproduction, transport, and nutrition based on the lecture material.

Main Characteristics of Plants

Eukaryotic, multicellular, photosynthetic autotrophs with tissues, gametangia, sporangia, multicellular dependent embryos, and apical meristems.

Apical Meristems

Areas at the tips of roots and shoots where cell division occurs, allowing primary growth.

Alternation of Generations

The plant life cycle that alternates between a multicellular haploid gametophyte and a multicellular diploid sporophyte.

Sporophyte

The multicellular diploid generation in plants that produces haploid spores by meiosis.

Gametophyte

The multicellular haploid generation in plants that produces haploid gametes (sperm and eggs) by mitosis.

Xylem

Vascular tissue that transports water and minerals from roots to the rest of the plant.

Phloem

Vascular tissue that transports sugars and carbohydrates from photosynthetic areas to nonphotosynthetic areas.

Lignin

A strengthening material in cell walls that helps support plants.

Microphylls

Leaves with only one strand of vascular tissue.

Megaphylls

Leaves with multiple strands of vascular tissue.

Sporophyll

A modified leaf that has sporangia.

Sorus

A cluster of sporangia on a fern leaf.

Strobilus

A spike-like structure made of sporophylls.

Root Hairs

Tiny extensions of epidermal cells that increase surface area for absorption.

Root Cap

A protective cap at the root tip that protects the apical meristem.

Nodes

Areas on the stem where leaves or branches grow.

Internodes

Stem regions between nodes.

Stomata

Openings in leaves that allow gas exchange.

Guard Cells

Specialized cells that control the opening and closing of stomata.

Parenchyma cells

Least specialized plant cells; alive at maturity; perform metabolism, photosynthesis, and storage.

Collenchyma cells

Flexible support cells in growing parts of plants that are alive at maturity.

Sclerenchyma cells

Rigid support cells with thick secondary walls hardened by lignin; dead at maturity.

Dermal tissue

Protective outer covering of the plant.

Ground tissue

Tissue involved in photosynthesis, storage, and support.

Heterosporous

The condition of producing two types of spores: microspores and megaspores.

Microspores

Spores that develop into male gametophytes or pollen.

Megaspores

Spores that develop into female gametophytes inside ovules.

Pollen

A structure containing the male gametophyte that carries sperm to the egg.

Ovule

A structure containing the megasporangium, female gametophyte, and integuments; it develops into a seed after fertilization.

Gymnosperms

Seed plants that have naked seeds not enclosed in fruit.

Angiosperms

Seed plants that have seeds enclosed in fruit and produce flowers.

Stamen

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

Anther

The pollen-producing part of the stamen.

Pistil

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

Pollination

Transfer of pollen from anther to stigma.

Double Fertilization

Process where one sperm fertilizes the egg to form a diploid zygote, and the other fertilizes the polar nuclei to form triploid endosperm.

Water Potential

The combined effect of solute concentration and pressure that determines the direction of water movement.

Transpiration

Water loss from leaves through stomata.

TACT forces

The combined mechanism of Transpiration, Adhesion, Cohesion, and Tension that moves water through plants.

Cohesion

Water molecules sticking to each other by hydrogen bonds.

Adhesion

Water molecules sticking to the walls of xylem.

Phototropism

Plant growth toward or away from light.

Auxin

A hormone that causes stems to bend toward light.

Gravitropism

A plant's growth response to gravity.

Thigmotropism

A plant's growth response to touch.

Abscisic Acid (ABA)

A hormone that maintains seed dormancy and closes stomata during drought.

Ethylene

A hormone involved in stress responses, fruit ripening, leaf abscission, and senescence.

Gibberellins

Hormones that stimulate stem elongation, bolting, fruit development, and seed germination.

Cytokinins

Hormones that stimulate cell division, differentiation, anti-aging effects, and influence apical dominance.

Topsoil

The uppermost layer of soil containing humus and living organisms.

Humus

Decaying organic matter.

Loam

Fertile topsoil made of equal parts sand, silt, and clay.

Cation Exchange

Process where plant roots pump $H^+$ into soil to displace cations so they can be absorbed.

Mycorrhizae

Mutualistic fungi in plant roots that help absorb water and minerals.

Nitrogen-fixing bacteria

Bacteria that convert atmospheric nitrogen, $N_2$, into ammonia, $NH_3$.

Monocot

A type of plant with one cotyledon, parallel veins, and flower parts in 3s.

Eudicot

A type of plant with two cotyledons, net veins, and flower parts in 4s or 5s.