Topic 5.4: Non-Mendelian Genetics

What are "genetically linked" genes?

Genes located on the same chromosome.

What is "gene mapping"?

Using the probability that linked genes segregate together to calculate map distance (map units) between them.

Define Codominance.

Both alleles are expressed in the phenotype; the heterozygote is different from either homozygote.

Define Incomplete Dominance.

Neither allele masks the other; the heterozygote expresses a blended version of the phenotypes.

What are sex-linked traits?

Traits determined by genes located specifically on the X or Y (sex) chromosomes.

What is Pleiotropy?

A single gene expression that results in multiple different traits or effects.

Why do traits from chloroplasts and mitochondria not follow Mendelian rules?

They result from non-nuclear inheritance and are randomly assorted to gametes.

How are mitochondrial traits typically inherited in animals and plants?

Maternally (via the egg in animals and the ovule in plants).