Unit 4 AOS2 - Evolution

Adaptive radiation

The process in which organisms diversify rapidly into a variety of forms to adapt to different environments.

Allele frequency

The proportion of a specific allele among all allele copies in a population.

Allopatric speciation

The formation of new species in populations that are geographically isolated from one another.

Aneuploidy

A condition in which there is an abnormal number of chromosomes in a cell.

Antigenic drift

The gradual mutation of viral antigens that occurs as the virus replicates.

Antigenic shift

A major change in a virus, resulting from the reassortment of its genetic material.

Artificial selection

The intentional breeding of organisms to produce desired traits.

Bacterial resistance

The ability of bacteria to survive and reproduce despite the presence of antibiotics.

Block mutation

A mutation that involves large segments of DNA, potentially affecting multiple genes.

Bottleneck effect

A sharp reduction in the size of a population due to environmental events or human activities.

Chromosome abnormality

A structural or numerical alteration in chromosomes.

Conjugation

A process by which one bacterium transfers genetic material to another through direct contact.

Divergent evolution

The process by which two or more related species become more dissimilar over time.

Epidemic

A widespread occurrence of an infectious disease in a community at a particular time.

Evolution

The change in the heritable characteristics of biological populations over successive generations.

Fertile

Capable of producing offspring or vegetation.

Founder effect

Genetic variation that occurs when a new population is established by a very small number of individuals.

Frameshift mutation

A mutation that results from the insertion or deletion of nucleotides in a DNA sequence.

Gene flow

The transfer of genetic variation from one population to another.

Gene pool

The total collection of genes in a population at any one time.

Genetic diversity

The total number of genetic characteristics in the genetic makeup of a species.

Genetic drift

The change in the frequency of an existing gene variant in a population due to random sampling.

Genotype

The genetic constitution of an individual organism.

Karyotype

The number and visual appearance of the chromosomes in the cell nuclei of an organism.

Missense mutation

A mutation that results in a different amino acid being incorporated into a protein.

Mutagenic agent

An agent that causes genetic mutation.

Mutation

A change in the DNA sequence that can lead to changes in phenotype.

Natural selection

The process by which organisms better adapted to their environment tend to survive and produce more offspring.

Nonsense mutation

A mutation that creates a premature stop codon in the protein sequence.

Pandemic

An outbreak of a disease that occurs over a wide geographic area and affects an exceptionally high proportion of the population.

Phenotype

The observable physical or biochemical characteristics of an organism.

Point mutation

A mutation affecting only one or a few nucleotides in a gene sequence.

Polyploidy

The condition of having more than two complete sets of chromosomes.

Population

A group of individuals of the same species living in the same area.

Reproductive isolation

A set of conditions that prevent different species from interbreeding.

Selection pressures

Environmental factors that influence which individuals survive and reproduce.

Selective breeding

The process of breeding plants and animals for particular genetic traits.

Silent mutation

A mutation that does not change the amino acid sequence of a protein.

Speciation

The formation of new and distinct species in the course of evolution.

Species

A group of living organisms consisting of similar individuals capable of exchanging genes.

Substitution mutation

A mutation that replaces one nucleotide with another.

Sympatric speciation

The evolution of new species from a single ancestral species while inhabiting the same geographic region.

Viable

Capable of living or developing under normal circumstances.