Biology Lab Practical

Mechanisms of evolution — Mutation, natural selection, gene flow, genetic drift, nonrandom mating.

🌳 PHYLOGENY

Cladogram — A diagram showing evolutionary relationships.

Node — A common ancestor.

Root — The base of a cladogram (oldest ancestor).

Sister taxa — Two lineages sharing an immediate common ancestor.

Plesiomorphy — Ancestral trait.

Apomorphy — Derived trait.

Synapomorphy — Shared derived trait that defines a clade.

Homology — Similarity due to shared ancestry.

Homoplasy — Similarity due to convergent evolution.

Character matrix — Table of organisms and their traits used to build cladograms.

🦠 BACTERIOLOGY

Colony margin — The edge or border of a bacterial colony.

Entire margin — Smooth, even edge.

Undulate margin — Slightly wavy edge.

Lobate margin — Large rounded projections.

Filamentous margin — Hair-like projections.

Coccus — Spherical bacteria.

Bacillus — Rod-shaped bacteria.

Spirillum — Spiral-shaped bacteria.

Gram-positive — Thick peptidoglycan cell wall, stains purple.

Gram-negative — Thin peptidoglycan + outer membrane, stains pink.

Zone of inhibition — Clear area around antibiotic indicating bacterial sensitivity.

🦠 PROTISTS

Cilia — Short hair-like structures used for movement.

Flagella — Long whip-like structures for movement.

Pseudopodia — Cytoplasmic extensions used for movement and feeding.

Autotroph — Organism that makes its own food (photosynthesis).

Heterotroph — Organism that consumes other organisms.

Excavata — Protist supergroup including Euglena.

SAR — Protist supergroup including stramenopiles, alveolates, and rhizarians.

Archaeplastida — Supergroup including green algae and plants.

Amoebozoa — Supergroup including Amoeba.

🌿 NONVASCULAR & SEEDLESS VASCULAR PLANTS

Thallus — Undifferentiated plant body without true roots, stems, or leaves.

Gemmae cup — Structure for asexual reproduction in liverworts.

Strobilus — Cone-like structure containing sporangia.

Sorus — Cluster of sporangia on underside of fern frond.

Sporangium — Structure that produces spores via meiosis.

Rhizoid — Root-like anchoring structure (not vascular).

Rhizome — Horizontal underground stem.

Gametophyte — Haploid generation that produces gametes.

Sporophyte — Diploid generation that produces spores.

Antheridium — Male structure that produces sperm.

Archegonium — Female structure that produces egg.

Alternation of generations — Life cycle alternating between haploid and diploid stages.

🌱 PLANT GROUPS

Bryophyta — Mosses (nonvascular, gametophyte dominant).

Hepatophyta (Marchantiophyta) — Liverworts.

Lycophyta — Club mosses (seedless vascular).

Monilophyta — Ferns (seedless vascular).

Coniferophyta — Conifers (gymnosperms).

Ginkgophyta — Ginkgo.

Cycadophyta — Cycads.

Gnetophyta — Gnetophytes.

Anthophyta — Angiosperms (flowering plants).

🌲 SEED PLANTS

Gymnosperms — Seed plants with naked seeds (no fruit).

Angiosperms — Flowering plants with seeds enclosed in fruit.

Pollen — Male gametophyte in seed plants.

Pollen tube — Tube that delivers sperm to ovule.

Double fertilization — One sperm fertilizes egg, second forms endosperm (angiosperms).

Megasporangium — Structure that produces megaspores (female).

Microsporangium — Structure that produces microspores (male).

Dominant generation in seed plants — Sporophyte.