Plant Biology Flashcards

Flashcards covering key vocabulary and concepts from plant biology lecture notes.

Embryophytes

Land plants

Alternation of Generations

Plants and some algae perform this life cycle, alternating between a sporophyte (2n) and gametophyte (n) phase.

Algae vs Plants

Algae are usually unicellular/live in colonies, plants are multicellular. Both require moist environments and contain photosynthetic pigments.

Chara

An algae called muskgrass or skunkweed, large cells form thallus, stem has no supportive tissue.

Challenges of life on land for plants

Need structural support since water no longer provides buoyancy, exposed to mutagenic radiation, gamete movement impacted by dry conditions.

Advantages of life on land for plants

Sunlight and CO2 are more abundant, and there are no predators.

Plant adaptations to land

Tolerance to drying out (mosses), colonizing humid environments (ferns), resistance to desiccation, waxy cuticle, cell walls for support.

Apical Meristems

Regions of cell division giving rise to shoots and roots, increasing length.

Vascular Tissue

Helps move water and nutrients. Xylem for water transport, phloem for sugar/solute transport.

Plant Defense Mechanisms

Apparency (growing away from predators), structural defenses (thorns/spines), chemical defenses (unappealing tastes/smells).

Bryophytes

Non-vascular plants (liverworts, hornworts, mosses) that lack lignin and require moist habitats, gametophyte dominant, appeared ~470 MYA.

Liverworts

Most primitive nonvascular plants, gametophyte dominant, no leaves or stomata, reproduce asexually via gemmae.

Hornworts

A type of bryophyte that has stomata, gametophyte dominant.

Mosses

A type of bryophyte, have a primitive conductive system, gametophyte dominant, sporophyte has stomata, anchored by rhizoids.

Seedless Vascular Plants

Plants that have vascular tissue and are sporophyte dominant. They rely on damp habitats and have true leaves and roots.

Lycophyta

Earliest group of seedless vascular plants - club mosses, quillworts, spike mosses. Sporophyte dominant.

Equisetopsida (Horsetails)

Seedless vascular plants characterized by nodes; leaves and branches come out as whorls from joints

Psilotopsida (Whisk Ferns)

Seedless vascular plants that have no roots or leaves; photosynthesis in stems that branch dichotomously.

Polypodiopsida (True Ferns)

Seedless vascular plants that have large fronds, sporophyte dominant, rely on water for fertilization.

Seed Plants

Rely less on water, include gymnosperms and angiosperms. Seeds resist desiccation and are dormant until conditions are favorable.

Pollen

Male gametophytes that reduce reliance on water for fertilization, distributed by wind/water/animals, protected from desiccation.

Gymnosperms

Have "naked seeds," separate female and male gametophytes, pollination by wind/insects, seeds not enclosed in ovary.

Conifers

Dominate phylum of gymnosperms, cold/drought tolerant, tall trees with scalelike/needlelike leaves, thick cuticle.

Cycads

Grow in tropical climates, appear similar to palms, bear large strobili/cones.

Ginkgophytes

Have one living species (Ginkgo biloba), male and female organs on separate plants.

Gnetophytes

Gymnosperm shrub with broad leaves resembling angiosperms

Angiosperms

Have flowers and fruits, sporophyte dominant, flowers aid in reproduction by attracting pollinators, fruits aid seed dispersal.

Fruits

Derived from multiple tissues, can be fleshy or dry, aid seed dispersal.

Monocots

Angiosperms with one cotyledon, veins run parallel, flower parts in threes, true woody tissue rare.

Dicots

Angiosperms with two cotyledons, veins form a network, flower parts in fours/fives, vascular tissue forms a ring.