DNA & Chromosomes:

• DNA (deoxyribonucleic acid): The molecule that carries genetic instructions.

• Gene: A unit of heredity that carries a specific trait instruction.

• Allele: Different versions of a gene (e.g., brown eye allele, blue eye allele).

• Chromosome: Thread-like structures in the cell nucleus that carry genes.

Genetic Variation & Inheritance:

• Genetic variation: Differences in DNA sequences between individuals.

• Genotype: An individual's complete set of genes.

• Phenotype: The observable traits of an organism (e.g., eye color, height).

• Dominant allele: An allele that masks the effect of a recessive allele when paired together.

• Recessive allele: An allele that is only expressed when paired with another recessive allele.

• Homozygous: Having two identical alleles for a particular gene.

• Heterozygous: Having two different alleles for a particular gene.

Mendelian Genetics:

• Law of Segregation: Alleles separate during gamete formation (sperm and egg cells).

• Law of Independent Assortment: Genes for different traits segregate independently during gamete formation.

Other:

• Punnett square: A tool used to predict the probability of offspring genotypes in a genetic cross.

• Genetic disorder: A condition caused by abnormalities in genes or chromosomes.