Genetic Inheritance And Interactions Flashcards
Explain what a phenotype is
The physical traits inherited from the parents
What is an allele
A variant of a gene
Explain what a genotype is
A genetic characteristic inherited from the parents
What is a gene
A section of DNA
What does homozygous mean
2 copies of the same allele
What does heterozygous mean
2 copies of a different allele
Explain lethal alleles
These lead to death in the animals that have them. They can be dominant or recessive.
Explain incomplete dominance
Neither allele is completely dominant to the other. This produces a new phenotype where the heterozygous animal will look different to both homozygous animals.
Explain Codominance
Neither allele is completely dominant to the other. Both alleles are shown at the same time in the phenotype.
Explain epistatic effects
This is where one gene affects the expression of another gene
Explain sex-linkage
This is where genes are carried on the sex chromosomes (X or Y)
Explain sex-influenced
The phenotype depends on the gender of the animal, It is influenced by sex hormones.
Explain multiple alleles
Three or more alternative alleles of a single gene are possible
Give some examples of lethal alleles
- Creeper disease in chickens
- Yellow fur in mice
- Roan & Dalmatian colouring in Guinea pigs
- Parrot jaw in cattle
- Overo lethal white foal syndrome
