Mendelian Genetics: Single and Polygenic Traits

Single gene traits

Traits controlled by one gene, usually with two alleles.

Polygenic traits

Traits influenced by multiple genes, allowing many genotypes.

TAS2R38

Taste receptor gene on chromosome 7 affecting bitterness.

SNPs

Single nucleotide polymorphisms causing allelic variations.

Phenylthiocarbamide (PTC)

Chemical that some can taste, linked to TAS2R38.

Propylthiouracil (PROP)

Another bitter chemical influenced by taste receptors.

Strong tasters

Individuals who can taste PTC and PROP effectively.

Non tasters

Individuals who cannot taste PTC or PROP.

Mild tasters

Individuals with a limited ability to taste PTC.

Dominant allele

An allele that expresses its trait over a recessive one.

Widow's peak

V-shaped hairline trait controlled by a dominant allele.

Straight hairline

Homozygous recessive trait represented as 'ww'.

Attached ear lobes

Recessive trait represented as 'aa'.

Free ear lobes

Dominant trait represented as 'AA' or 'Aa'.