BIO130 - Exam 3 - Lecture 3

Genotype

Chromosomes that contain genes

Genes encoded by proteins, proteins lead to phenotype, genotype leads to phenotype

Mendelian Inheritance

A given gene can have different versions/variations

These variations are called alleles

Diploid organisms

have two copies of each chromosome, therefore two copies of each gene

Homozygous

Two of the same allele

will have phenotype of the allele version they have

Heterozygous

For any given gene, one allele is dominant, the other is recessive

heterozygous individuals will have the phenotype of the dominant all

3 possible genotypes

Homozygous dominant - dominant phenotype

Homozygous recessive - recessive phenotype

Heterozygous - dominant phenotype

Parents

both diploid but only one chromosome gets passed to offspring

random and results in many possible outcomes

Punnett Squares

One gene at a time, assign it a letter

Uppercase if dominant allele, lowercase if recessive allele