all bio terms for ost

Homeostasis

The process of maintaining a stable internal environment.

Prokaryote

A simple cell with no nucleus (Bacteria).

Eukaryote

A complex cell with a nucleus and organelles (Plants/Animals).

Cell Membrane

Selectively permeable boundary that controls what enters/leaves.

Passive Transport

Movement of molecules from High to Low concentration (No Energy).

Active Transport

Movement of molecules from Low to High concentration (Requires ATP).

Osmosis

The diffusion of water across a membrane.

Mitochondria

Organelle where Cellular Respiration happens (makes ATP).

Chloroplast

Organelle where Photosynthesis happens (makes Glucose).

ATP

The main energy molecule used by cells.

Enzyme

A protein that speeds up chemical reactions (Catalyst).

Denature

When an enzyme changes shape due to heat/pH and stops working.

Photosynthesis

Carbon dioxide + water + light energy glucose + oxygen

Cellular Respiration

Glucose + Oxygen Carbon Dioxide + Water + ATP

Mitosis

Cell division for growth/repair; makes 2 identical diploid cells.

Protein

Biomolecule used for structure and enzymes (made of Amino Acids).

Carbohydrate

Biomolecule used for quick energy (Sugars).

Lipid

Biomolecule used for long-term energy and membranes (Fats).

Nucleic Acid

Biomolecule that stores genetic info (DNA/RNA).

Ribosome

The organelle where proteins are made.

DNA

Double-helix molecule carrying genetic instructions.

Nucleotide

Building block of DNA (Sugar, Phosphate, Nitrogen Base).

Transcription

Copying DNA into mRNA (happens in Nucleus).

Translation

mRNA is "read" to build a protein (happens at Ribosome).

Meiosis

Division that creates 4 unique haploid gametes (Sperm/Egg).

Crossing Over

Homologous chromosomes swap DNA during Meiosis (leads to Variation).

Haploid (n)

A cell with half the normal number of chromosomes.

Diploid (2n)

A cell with a full set of chromosomes.

Genotype

The actual letters/alleles (e.g., Bb).

Phenotype

The physical trait you see (e.g., Brown eyes).

Allele

Different versions of a gene.

Homozygous

Having two of the same alleles (BB or bb).

Heterozygous

Having two different alleles (Bb).

Dominant

The trait that shows up even if only one allele is present.

Recessive

The trait that is hidden unless two alleles are present.

Incomplete Dominance

Traits blend (Red + White = Pink).

Codominance

Both traits show up (Black + White = Spotted).

Sex-Linked Trait

Trait carried on the X chromosome (more common in males).

Mutation

A change in the DNA sequence.

Pedigree

A chart showing how a trait is passed through generations.

Natural Selection

Organisms with best-fit traits survive and reproduce.

Adaptation

A trait that helps an organism survive in its environment.

Fitness

An organism's ability to survive AND reproduce.

Common Ancestor

An older species that two newer species evolved from.

Homologous Structure

Similar bone structure, different function (Shows common ancestry).

Analogous Structure

Different structure, same function (Does NOT show common ancestry).

Vestigial Structure

A leftover structure with no current use (e.g., whale hip bones).

Cladogram

A diagram showing evolutionary relationships.

Speciation

The creation of a new species.

Geographic Isolation

When a physical barrier (river/mountain) splits a population.

Genetic Drift

Random change in a population's genes (usually in small groups).

Gene Flow

Movement of genes into or out of a population (migration).

Endosymbiosis

Theory that mitochondria/chloroplasts were once independent bacteria.

Taxonomy

The science of naming and classifying organisms.

Binomial Nomenclature

Two-part scientific name (Genus species).

Phylogeny

The evolutionary history of a species.

Dichotomous Key

A tool used to identify organisms through a series of choices.

Domain

The largest classification group (Bacteria, Archaea, Eukarya).

Biodiversity

The variety of life in an area.

Fossil Record

History of life as documented by fossils.

Biotic Factor

A living part of an ecosystem.

Abiotic Factor

A non-living part of an ecosystem (temperature, water).

Trophic Level

A step in a food chain/web.

Producer

Organism that makes its own food (Autotroph).

Consumer

Organism that eats others for energy (Heterotroph).

Decomposer

Organism that breaks down dead matter (Recycles nutrients).

10% Rule

Only 10% of energy is passed to the next level in a food pyramid.

Food Web

Overlapping food chains in an ecosystem.

Symbiosis

A close relationship between two different species.

Mutualism

Both species benefit (+/+).

Commensalism

One benefits, the other is unaffected (+/0).

Parasitism

One benefits, the other is harmed (+/-).

Carrying Capacity

The maximum number of individuals an environment can support.

Limiting Factor

Something that stops a population from growing (e.g., food, space).

Exponential Growth

Rapid, unchecked population growth (J-curve).

Logistic Growth

Growth that levels off at carrying capacity (S-curve).

Succession

The predictable changes in an ecosystem over time.

Pioneer Species

The first species to live in a barren area (e.g., Lichen).

Niche

An organism's specific role in its habitat.

Keystone Species

A species that has a huge impact on its entire ecosystem.