Biology Part 2: Evolution & Genetics

Antibiotics

Medicines that kill bacteria or prevent their growth.

Superbugs

Bacteria that have developed resistance to multiple antibiotics.

Acquired trait

A feature gained during an individual's lifetime, like a tattoo.

Genetic trait

A feature passed down by genes from parents to offspring.

Mutations

Random changes in DNA that can create differences between organisms.

Crossing over

The swapping of DNA between homologous chromosomes during meiosis.

Independent assortment

The random alignment and separation of chromosomes during meiosis.

Population

A group of organisms of the same species living in the same place.

Evolution

Any change in genetic traits in a population over many generations.

Genetic diversity

The amount of genetic variation within a population.

Natural selection

Process where better-suited organisms have more opportunities to reproduce.

Selection pressures

Any challenge that affects an organism's ability to survive.

Artificial selection

The breeding of organisms by humans for particular traits.

Gene pool

The combination of genes and alleles present in a population.

Structural adaptation

A physical body feature that helps an organism survive.

Behavioral adaptation

An action or behavior that helps an organism survive.

Physiological adaptation

An internal body process that helps an organism survive.

Speciation

The process where one population splits into distinct new species.

Geographical isolation

Population separation caused by physical barriers like oceans or mountains.

Fossils

Preserved remains or traces of organisms that lived long ago.

Homologous structures

Body structures with similar underlying features inherited from a common ancestor.

Vestigial organs

Structures inherited from ancestors that have little or no current function.

Biogeography

The study of why plants and animals live in particular places globally.

Alleles

Different versions of the same gene.

Phylogenetic tree

A diagram showing evolutionary relationships and common ancestors.

Fitness

An organism's ability to survive and reproduce in its environment.

Genotype

The genetic makeup of an organism.

Phenotype

The observable physical characteristics of an organism.

Genetic drift

Random changes in allele frequencies in a population over time.

Bottleneck effect

A sharp reduction in population size resulting in a loss of genetic diversity.

Founder effect

Loss of genetic variation when a new population is established by a small number of individuals.