College biology final

Prokaryotic cell

Cell that lacks a nucleus and membrane-bound organelles; example: bacteria like E. coli

Eukaryotic cell

Cell with a nucleus and membrane-bound organelles; example: human or plant cells

Unicellular organism

Organism made of one cell that performs all life functions

Multicellular organism

Organism made of many specialized cells

Cell membrane

Selectively permeable barrier that controls what enters and leaves the cell

Cell wall

Rigid structure that provides support and protection; found in plants, fungi, and bacteria

Cytoplasm

Jelly-like substance where chemical reactions occur

Vacuole

Stores water, nutrients, and waste; large in plant cells

Nucleus

Contains DNA and controls cell activities

Ribosomes

Site of protein synthesis

Lysosome

Digests waste and old cell parts

Chloroplast

Site of photosynthesis

Mitochondria

Produces ATP through cellular respiration

Cell size and surface area

Cells stay small to maintain a high surface area-to-volume ratio

Diffusion

Movement of particles from high to low concentration

Osmosis

Diffusion of water across a selectively permeable membrane

Passive transport

Movement across a membrane without energy

Active transport

Movement across a membrane using ATP

Allele

Different versions of the same gene

Dominant allele

Allele expressed if present

Recessive allele

Allele expressed only when two copies are present

Homozygous

Two identical alleles; BB or bb

Heterozygous

Two different alleles; Bb

Monohybrid cross

Punnett square tracking one trait

Dihybrid cross

Punnett square tracking two traits

Genotype

Genetic makeup of an organism

Phenotype

Physical appearance of a trait

Phenotypic ratio

Ratio predicting trait outcomes; example: 3:1

Incomplete dominance

Blended phenotype

Codominance

Both alleles fully expressed

Multiple alleles

Trait controlled by more than two alleles

Sex-linked trait

Trait located on a sex chromosome

Producer

Organism that makes its own food through photosynthesis

Primary consumer

Organism that eats producers

Secondary consumer

Organism that eats primary consumers

Tertiary consumer

Top predator

Energy flow

Energy moves upward and decreases at each level

10 percent rule

Only about 10 percent of energy transfers to the next trophic level

Competition

Organisms competing for limited resources

Predation

One organism hunts and eats another

Mutualism

Both organisms benefit

Commensalism

One benefits, other unaffected

Parasitism

One benefits, one harmed

Batesian mimicry

Harmless species mimics a harmful one

Mullerian mimicry

Two harmful species resemble each other

Food chain

Single pathway of energy transfer

Food web

Multiple interconnected food chains

Carrying capacity

Maximum population an environment can support

Limiting factor

Resource that restricts population growth

Biotic factor

Living part of an ecosystem

Abiotic factor

Nonliving part of an ecosystem

Virus

Nonliving infectious agent made of genetic material and protein

Are viruses living

No, they cannot reproduce independently

Capsid

Protein coat surrounding viral genetic material

Envelope

Outer membrane on some viruses

Lytic cycle

Virus replicates and kills host cell

Lysogenic cycle

Viral DNA integrates into host DNA and remains dormant

Bacteriophage

Virus that infects bacteria

DNA virus

Virus that mutates slowly

RNA virus

Virus that mutates quickly

Viral transmission

Spread through contact, air, or vectors

Bacteria

Prokaryotic organisms lacking a nucleus

Binary fission

Asexual reproduction producing two identical cells

Antibiotic

Drug that kills bacteria

Antibiotic resistance

Ability to survive antibiotics

Horizontal gene transfer

Exchange of DNA between bacteria

Conjugation

DNA transfer through a pilus

Transformation

Uptake of DNA from environment

Transduction

DNA transfer via viruses

Gram-positive bacteria

Purple stain; thick cell wall

Gram-negative bacteria

Pink stain; thin cell wall

Endospore

Dormant survival structure

Pathogen

Disease-causing organism

Vaccine

Prepares immune system to fight disease

Emerging disease

Newly appearing or increasing disease

Protist

Eukaryotic organism mostly found in water

Animal-like protist

Ingests food; amoeba

Plant-like protist

Photosynthetic; algae

Fungus-like protist

Absorbs nutrients; slime mold

Pseudopod

Temporary extension for movement

Cilia

Short hair-like structures for movement

Flagella

Long whip-like structure for movement

Alternation of generations

Life cycle with different multicellular stages

Malaria

Protist disease spread by mosquitoes

Algal bloom

Rapid growth of algae disrupting ecosystems

Fungus

Eukaryotic heterotroph that absorbs nutrients

Saprotroph

Feeds on dead organic matter

Parasitic fungus

Feeds on a living host

Hyphae

Threadlike fungal filaments

Mycelium

Network of hyphae

Fruiting body

Spore-producing structure

Spore

Reproductive cell

Chitin

Polysaccharide in fungal cell walls

Asexual reproduction

Reproduction without genetic exchange