Biol 110 Exam #2

Biol Study Guide

Bacterial Chromosome

A single circular DNA molecule located in the nucleoid region

Plasmid

A small, circular, self-replicating DNA molecule that is non-essential but carries extra traits

Cocci

Spherical-shaped prokaryotic cells

Bacilli

Rod-shaped prokaryotic cells

Spirilla

Spiral-shaped prokaryotic cells

Peptidoglycan

The main structural component of the bacterial cell wall

Gram-Positive

Bacteria with a thick peptidoglycan layer that appears purple after a Gram stain

Gram-Negative

Bacteria with a thin peptidoglycan layer and an outer membrane that appears pink after a Gram stain

Endospore

A dormant, thick-walled resistant structure that allows bacteria to survive harsh conditions

Glycocalyx

A sticky outer layer (capsule or slime) used for attachment and immune evasion

Flagella

Tail-like appendages used by prokaryotes and protists for motility

Sex Pili

Appendages used to pull two bacteria together for horizontal gene transfer

Microbiome

The community of microorganisms living in a specific environment

Biofilm

A surface-coating colony of prokaryotes that engage in metabolic cooperation

Photoautotroph

An organism that uses light for energy and CO2 for carbon

Chemoheterotroph

An organism that uses organic compounds for both energy and carbon

Obligate Aerobe

An organism that requires oxygen for cellular respiration

Obligate Anaerobe

An organism that is poisoned by oxygen and lives in anaerobic environments

Nitrogen Fixation

The conversion of atmospheric N2 into ammonia (NH3) by bacteria

Binary Fission

The asexual process of cell division in prokaryotes

Horizontal Gene Transfer

The movement of genetic material between organisms without reproduction

Endosymbiosis

The theory that mitochondria and chloroplasts originated as engulfed bacteria

Contractile Vacuole

An organelle in protists that pumps out excess water

Pseudopod

A temporary extension of the cytoplasm used for movement and feeding

Phytoplankton

Photosynthetic protists that drift near the ocean surface

Hyphae

The thread-like filaments that make up the body of a multicellular fungus

Mycelium

A densely branched network of hyphae forming the body of a fungus

Chitin

The strong polysaccharide that makes up fungal cell walls

Septate Hyphae

Hyphae divided into cells by cross-walls called septa

Coenocytic Hyphae

Hyphae that lack septa and consist of a continuous cytoplasmic mass with many nuclei

Plasmogamy

The fusion of the cytoplasm from two parent mycelia

Karyogamy

The fusion of haploid nuclei to form a diploid zygote

Dikaryon

A fungal cell containing two separate haploid nuclei (N+N)

Lichen

A symbiotic association between a fungus and a photosynthetic partner

Mycorrhizae

A mutualistic association between a fungus and the roots of a plant