Genetics Cheat Sheet

Genetics Cheat Sheet

DNA = Sequence of nucleotides that codes traits.

Chromosomes = Compact units of DNA.

Genes = Sections of DNA that code for a specific trait. These are found on chromosomes.

DNA à Chromosomes à Genes

Alleles = Different forms of a gene.

Alleles are represented by letters.

CAPITAL LETTER = DOMINANT

LOWER CASE LETTER = RECESSIVE

Example: T = tallness __ = ____________________

T= shortness. __ = ____________________

Gene combination determines trait.

Dominant= the allele that mask the expression of the recessive allele

Recessive= the allele whose expression is masked by the dominant allele.

TT = Tall ___ = ____________________

Tt = Tall ___ = ____________________

Tt = Short ___ = ____________________

Genotype= is the gene combination.

Example: TT, Tt, tt ________________________

Phenotype= is the expressed trait.

Example: Tall or Short. ________________________

Homozygous= two identical alleles for the same gene.

Example: TT, tt ____________

Heterozygous= two different alleles for the same gene.

Example: Tt ____________