Bryophytes and Plant Biology

These flashcards cover key terms and concepts related to bryophytes and broader plant biology, facilitating study for an exam.

Bryophytes

Nonvascular plants including mosses, liverworts, and hornworts that require water for reproduction and have a dominant gametophyte stage.

Nonvascular Plants

Plants lacking xylem and phloem; absorb water directly through tissues.

Alternation of generations

Life cycle alternating between haploid gametophyte and diploid sporophyte.

Gametophyte

Haploid stage that produces gametes by mitosis; dominant stage in bryophytes.

Sporophyte

Diploid stage that produces spores by meiosis; attached to gametophyte in bryophytes.

Antheridium

Male structure that produces sperm.

Archegonium

Female structure that produces eggs.

Why bryophytes need water

Sperm are motile and must swim to egg for fertilization.

Rhizoids

Root-like structures that anchor bryophytes but do not transport water.

Sporangium

Structure where spores are produced by meiosis.

Protonema

Early developmental stage of moss gametophyte.

Sphagnum moss

Moss that absorbs 20–25x its weight in water and forms peat bogs.

Gemmae cups

Asexual reproductive structures in liverworts that disperse clones via water splash.

Elaters

Structures that help disperse spores in liverworts.

Hornwort symbiosis

Hornworts contain Nostoc cyanobacteria that fix nitrogen.

Bryophyte ecology

Pioneer species that help form soil and tolerate harsh environments.

Endophyte

Fungus or bacteria living inside plant tissue without causing disease.

Endophyte benefits

Disease resistance, herbivore protection, stress tolerance, improved nutrient uptake.

Mycorrhizae

Symbiotic relationship between fungi and plant roots improving nutrient and water uptake.

Ectomycorrhizae

Fungus surrounds root cells but does not penetrate cell membrane.

Endomycorrhizae (VAM)

Fungus enters root cells forming arbuscules to increase nutrient exchange.

Lichen

Symbiotic relationship between fungus and algae or cyanobacteria.

Fungus role in lichen

Provides protection, structure, and mineral absorption.

Algae/cyanobacteria role in lichen

Performs photosynthesis and produces sugars.

Lichen ecological role

Break down rock, form soil, fix nitrogen, tolerate extreme environments.

Crustose lichen

Flat and tightly attached to substrate.

Foliose lichen

Leaf-like structure loosely attached.

Fruticose lichen

Branching or shrubby appearance.

Totipotency

Ability of a plant cell to develop into a whole plant.

Micropropagation

Growing many identical plants from small tissue samples in sterile media.

Callus

Mass of undifferentiated plant cells formed during tissue culture.

Plant tissue culture hormones

Auxins and cytokinins regulate root and shoot formation.

Agrobacterium tumefaciens

Bacterium that naturally inserts DNA into plant genome and is used in genetic engineering.

Transgenic plant

Plant genetically modified with DNA from another organism.

Golden rice

Genetically modified rice that produces beta-carotene (vitamin A precursor).

Somatic hybridization

Fusion of plant cells from different species to combine genetic traits.

Soil components

Solid minerals and organic matter, liquid water and nutrients, gas oxygen and nitrogen.

Cation exchange

Process where positively charged nutrients bind to negatively charged soil particles.

Ideal soil pH

5.5–6.5 for optimal nutrient availability.

Role of soil microbes

Break down organic matter and release nutrients for plant uptake.