Freshman Biology Review - Vocabulary Flashcards

Vocabulary-style flashcards covering key terms from ecology, biochemistry, cells, genetics, evolution, and immunology.

Biodiversity

The variety of living things in an ecosystem and their interactions; changes with extinction and evolution (coral reefs have very high biodiversity).

Food web

All the feeding relationships within a single ecosystem, consisting of multiple interconnected food chains.

Emigration

Individuals leaving a population, reducing its size and genetic variation.

Immigration

New individuals entering a population, increasing its size and genetic variation.

Birth rate

Number of births in a population; higher births increase population size.

Death rate

Number of deaths in a population; higher deaths decrease population size.

Food availability

The amount of usable food in an environment; scarcity can shrink populations.

Decomposers

Organisms that break down dead matter and recycle nutrients (e.g., mushrooms, yeast, slugs, snails, flies, beetles).

Autotrophs

Organisms that make their own food (e.g., plants, algae, seaweed).

Photosynthesis

Process by which autotrophs convert light energy, CO2, and water into glucose and oxygen.

Respiration

Process by which cells convert glucose and oxygen into ATP, releasing CO2 and water; occurs in mitochondria.

Decomposition

Breakdown of dead matter by decomposers, returning nutrients to the environment.

Combustion

Burning of fossil fuels, releasing CO2 and water into the atmosphere.

Weathering and sedimentation

Carbon can be stored in rocks and sediments for long periods.

Ocean absorption and release

The ocean absorbs CO2 from the atmosphere and can release it back.

Carbon cycle

Movement of carbon through the atmosphere, biosphere, oceans, and geosphere via processes like photosynthesis, respiration, decomposition, combustion, and ocean exchange.

Nitrogen cycle

Movement of nitrogen through soils, organisms, and atmosphere; nitrates/ammonia are taken up by plants; bacteria convert nitrate to nitrogen gas.

Transpiration

Plants releasing water vapor into the atmosphere through stomata; part of the water cycle.

Population

Number of individuals of a species in a given area.

Community

Interactions and relationships between populations of different species in an area.

Ecosystem

All living organisms and their nonliving components (water, air, nitrogen, carbon) in an area.

Hydrogen bonds

Weak bonds between hydrogen and electronegative atoms; can also form with other surfaces.

Lipid

Fatty molecules; fats, oils, and related compounds.

Polymer

Large molecule made of repeating smaller units (monomers).

Protein

Macromolecule made of amino acids; performs many cellular functions and acts as enzymes.

Chloroplast

Plant cell organelle where photosynthesis occurs and chlorophyll is located.

Chlorophyll

Green pigment that captures light energy for photosynthesis.

Mitochondria

Organelle where cellular respiration occurs; produces ATP.

Rough endoplasmic reticulum

ER with ribosomes; synthesizes proteins for secretion or membranes.

Smooth endoplasmic reticulum

ER without ribosomes; lipid and hormone production.

Golgi apparatus

Modifies, sorts, and ships proteins and lipids to their final destinations.

Ribosome

Organelle where proteins are synthesized using mRNA.

Nucleus

Organelle that houses genetic material and controls cellular activities.

Plant cell vs. Animal cell

Plant cells have cell walls and chloroplasts; animal cells have lysosomes and centrioles.

Mitosis

Cell division that produces two genetically identical daughter cells.

Cell membrane

Semi-permeable phospholipid bilayer surrounding the cell; regulates substance movement.

Diffusion

Movement of molecules from high concentration to low concentration, driven by concentration gradient.

Osmosis

Diffusion of water across a semi-permeable membrane from low solute concentration to high.

Active transport

Movement of substances against their concentration gradient, requiring energy.

Passive transport

Movement of substances down their gradient without energy input.

Phospholipid bilayer

Two-layer arrangement of phospholipids forming the cell membrane with hydrophilic heads and hydrophobic tails.

Integral proteins

Membrane proteins that span the membrane and form channels for specific molecules.

Peripheral proteins

Membrane proteins on the surface; can act as enzymes or receptors.

Exocytosis

Process of exporting materials from the cell via vesicles fusing with the membrane.

Endocytosis

Process of taking substances into the cell by surrounding them in a vesicle.

Enzymes

Proteins that act as catalysts to speed up biochemical reactions and are not consumed.

Activation energy

Energy required to start a chemical reaction; enzymes lower this energy barrier.

Denaturation

Loss of enzyme shape and function due to heat or chemicals.

Cellular respiration

Process of turning glucose and oxygen into ATP, CO2, and water; occurs in mitochondria.

Meiosis

Cell division that produces four haploid gametes from germ cells, involving two divisions.

Gametes

Reproductive cells (sperm and eggs) produced by meiosis.

Zygote

First cell of a newly fertilized organism.

Genotype

Genetic makeup of an organism (the alleles an individual carries).

Phenotype

Observable traits of an organism resulting from the genotype and environment.

Dominant allele

Allele that masks a recessive allele in a heterozygous individual.

Recessive allele

Allele that is masked by a dominant allele in a heterozygous individual.

Homozygous dominant

Two dominant alleles (e.g., FF) in an individual.

Homozygous recessive

Two recessive alleles (e.g., ff) in an individual.

Heterozygous

Two different alleles (e.g., Ff) in an individual.

Blood type

ABO blood group system; phenotypes A, B, AB, or O based on alleles A, B, and i.

Carrier

An individual who has one copy of a recessive allele but is phenotypically normal; can pass the allele to offspring.

Color blindness

X-linked recessive trait; often more common in males; females can be carriers.

Evolution

Change in allele frequencies in a population over generations due to natural selection, mutation, genetic drift, etc.

Adaptation

A trait that increases an organism's chances of surviving and reproducing in its environment.

Homologous structures

Body parts in different species that share common ancestry and bone structure.

Vestigial structures

Remnants of features that served important functions in ancestors but have reduced function now.

Natural selection

Process by which individuals with advantageous traits are more likely to reproduce.

Acquired trait

Trait developed during a lifetime, not inherited (e.g., skills or injuries).

Mutation

A change in the DNA sequence; a primary source of genetic variation.

Reproductive isolation

When populations evolve barriers to interbreeding, leading to speciation.

Genetic drift

Random changes in allele frequencies due to chance events.

Bottleneck effect

Sharp reduction in population size that reduces genetic variation.

Founder effect

New population started by a few individuals, reducing genetic variation.

Integumentary system

Skin, nails, and mucous membranes; first line of defense against infection.

Vaccine

A preparation of weakened or inactive pathogens that stimulates an immune response.

Antibodies

Proteins produced by the immune system that recognize and neutralize antigens.

HIV

Human immunodeficiency virus; weakens the immune system by attacking T cells.

Inflammation

Immune response that increases blood flow and recruits immune cells to injury sites.