Simplified notes

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

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.

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.

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.