Gregor Mendel's experiments with pea plants established the fundamental laws of inheritance.

Human somatic cells have 46 chromosomes in total, which consist of 23 pairs.

Phenotype refers to the physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.

A gene is a distinct sequence of nucleotides forming part of a chromosome, the order of which determines the order of monomers in a polypeptide.

Helicase is the enzyme that breaks the hydrogen bonds between the base pairs of DNA, separating the two strands.

Homozygous means having two identical alleles of a particular gene or genes.

Purines are double-ring structures (Adenine and Guanine), while pyrimidines are single-ring structures (Cytosine, Thymine, and Uracil).

An allele is one of two or more versions of a DNA sequence at a given genomic location.

Hydrogen bonds form between the complementary nitrogenous bases to hold the two strands of the DNA double helix together.

In DNA, Guanine always forms three hydrogen bonds with Cytosine according to Chargaff's rules.

A nucleosome is the basic repeating unit of eukaryotic chromatin, comprising DNA wrapped around a core of histone proteins.

George Beadle and Edward Tatum proposed the one gene-one enzyme hypothesis, suggesting each gene encodes a single enzyme.

In codominance, neither allele is recessive, and both are fully expressed in the phenotype, such as in AB blood type.

The genome represents the complete set of genetic material present in an organism or cell.

DNA Polymerase is the enzyme that catalyzes the addition of nucleotides to the growing DNA chain during replication.

A cross between AA and aa always results in 100% Aa (heterozygous) offspring in the F1 generation.

The centromere is the specialized DNA sequence that links a pair of sister chromatids and acts as the site for spindle fiber attachment.

Polygenic traits are controlled by two or more genes; human skin color is a classic example of continuous variation determined by multiple genes.

Transcription is the process by which information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA).