Inheritance, Variation and Evolution (AQA)

DNA

Deoxyribonucleic Acid, the genetic material found in the nuclei of cells, carrying instructions for protein synthesis.

Nucleotide

The basic building block of DNA, consisting of a sugar, phosphate group, and a base.

Adenine

One of the four bases in DNA, paired with thymine.

Thymine

One of the four bases in DNA, paired with adenine.

Cytosine

One of the four bases in DNA, paired with guanine.

Guanine

One of the four bases in DNA, paired with cytosine.

Gene

A short section of DNA that codes for a specific protein.

Genome

The entire genetic material of an organism.

Protein Synthesis

The process of creating proteins from DNA, occurring in two stages: transcription and translation.

Transcription

The process where DNA is used to create a messenger RNA (mRNA) copy.

Translation

The process where mRNA is read at the ribosome to synthesize a chain of amino acids.

Mutation

A change in the DNA sequence that can affect protein function.

Allele

Different forms of a gene inherited from each parent.

Dominant Allele

An allele that only needs one copy to be expressed.

Recessive Allele

An allele that requires two copies to be expressed.

Punnett Square

A genetic diagram used to predict the probability of offspring inheriting certain traits.

Homozygous

Having two identical alleles for a gene.

Heterozygous

Having two different alleles for a gene.

Cystic Fibrosis

A genetic disorder caused by a recessive allele.

Polydactyly

A genetic condition characterized by extra fingers or toes, caused by a dominant allele.

XX

The chromosome pair that indicates a female.

XY

The chromosome pair that indicates a male.

Genetic Screening

The process of testing for genetic disorders before birth.

Variation

Differences among individuals caused by genetic and environmental factors.

Continuous Variation

A range of values for a trait influenced by multiple genes.

Discontinuous Variation

Distinct, separate categories for a trait, typically influenced by a few genes.

Evolution

The gradual change in species over time through natural selection.

Natural Selection

The process where individuals with favorable traits survive and reproduce.

Selective Breeding

Breeding organisms for specific desirable traits.

Genetic Engineering

The alteration of an organism's DNA to achieve desired traits.

Cloning

The process of producing genetically identical individuals.

Biotechnology

Utilizing biological processes for human benefit.

Fossils

Remains of ancient organisms, providing evidence for evolutionary change.

Antibiotic Resistance

The rapid evolution of bacteria to survive antibiotic treatment.

Classification

Grouping organisms based on similarities in DNA, biochemistry, and structure.