Year 10 Science: Evolution and Genetics

These flashcards cover key vocabulary and concepts from the Year 10 Science unit on Evolution, including genetics, Darwin's principles, selection types, and evidence for evolution.

DNA

Deoxyribonucleic acid.

Mutation

A permanent change in the genetic material of an organism; can lead to variation in genes.

Somatic mutations

Mutations that only affect the individual as they only occur in somatic (body) cells, which are non-reproductive cells.

Germline mutations

Mutations occurring in the germline (sperm and egg) cells that are inheritable and passed onto offspring.

Evolution

The process by which populations of organisms change over generations, which can result in new species.

Biological diversity

The variety of life that exists on Earth.

Species

The smallest unit of classification, referring to a group of similar individuals that breed to produce fertile offspring under natural conditions.

Morphology

The physical features of an organism.

Artificial selection

The process by which breeders select desirable characteristics and only breed animals or plants with those specific characteristics.

Sexual selection

A type of natural selection where individuals with certain traits are more likely to find a mate and reproduce successfully.

Natural selection

The process by which an environmental factor acts on a population, resulting in some organisms having a greater chance of survival than others.

Biotic factors

Living things that interact with an organism, such as competition, availability of food, predators, and disease.

Abiotic factors

Non-living things that interact with an organism, such as temperature, light, humidity, and the availability of air, water, and nutrients.

Fitness

An organism's ability to survive, reproduce, and pass on its genes to the next generation.

Meiosis

The process that creates gametes and halves the chromosome number from diploid ($2n$) to haploid ($n$).

Crossing over

A random exchange of genes within homologous pairs of chromosomes occurring early in meiosis.

Independent assortment

The process during meiosis where one chromosome from each homologous pair is randomly distributed to daughter cells, creating unique combinations of genes.

DDT

Dichlorodiphenyltrichloroethane; an insecticide originally used to kill mosquitoes and combat malaria.

Speciation

The process of one species splitting into two or more new species, involving three steps: variation, isolation, and selection.

Isolation

The prevention of different groups of the same species from breeding, often via a geographical barrier, which stops gene flow.

Hybrids

Offspring produced when two very similar species interbreed; they are often infertile or have health problems.

Theory

A simple explanation that brings together a host of different ideas and has been subjected to rigorous testing through observations and experiments.

Transitional forms

Organisms found in the fossil record that exhibit characteristics of two different species, representing a stage of evolution from one species to another.

Comparative anatomy

The science of comparing the physical structures of different species to find similarities indicating common ancestry or adaptive responses.

Homologous structures

Structures that are similar in related organisms because they were inherited from a common ancestor, even if they perform different functions.

Analogous structures

Features of different species that are similar in function but not necessarily in structure and do not derive from a common ancestor.

Cytochrome c

A protein found in all living organisms that scientists use to compare amino acids and determine how closely related species are.

Hox genes

Genes that specify the location and type of structures an organism grows at the embryonic stage, serving as building instructions for the body.

Embryology

The study of the development, structure, and function of embryos, which provides evidence for evolution through shared features like branchial arches.