Genotype to Phenotype

How is genotype manifested as a phenotype?

Genotype = DNA sequence → mRNA → protein structure → observable trait (phenotype

How do genotype and phenotype relate to DNA and proteins?

Genes in DNA code for proteins; proteins carry out functions that produce phenotypic traits.

How are these ideas used to help us understand and predict likely offspring (children) and their traits?

Knowing the parents’ genotypes and how alleles interact (dominant/recessive) allows prediction of offspring traits using Punnett squares.

What are dominant and recessive alleles?

Dominant alleles show their effect with just one copy; recessive alleles only affect phenotype when both copies are present.

What makes an allele recessive or dominant?

Usually depends on the protein’s function:
– Loss-of-function mutations are often recessive (no working protein if both copies are broken).
– Gain-of-function mutations are often dominant (overactive or extra protein function).

What is the relationship between dominant/recessive alleles and gain-of-function/loss-of-function mutations?

Gain-of-function = dominant (acts even with one copy).
Loss-of-function = recessive (only shows if both copies are mutant).