Genotype Phenotype + Inheritance Flashcards
What is a phenotype?
The observable characteristics of an indivual
Resulting from the interaction of its genotype with the environment
What does it mean that humans are diploids?
Two copies of each gene
One maternal and one paternal
What is an allele?
A different version of the same gene
At the same position on a chromosome
How many alleles does an individual have?
Two copies of each gene
What do homozygous, heterozygous and hemizygous mean?
Homo - the two alleles of a gene are the same
Hetero - the two alleles of a gene are the different
Hemi - only one allele of gene on the X chromosome
What does codominant mean?
Equal influence of two alleles on a phenotype
Neither allele can mask the expression of the other
What does autosomal mean?
Not sex linked
What is a pedigree tree used for?
For genetic counselling - calculate the probability of inheritance
What type of inheritance are men and women unequally affected?
X linked recessive
What type of inheritance can skip a generation?
Autosomal recessive
What does polygenic inheritance mean?
Give some examples
Phenotypes are influenced by multiple genes
Obesity, cancer
If there is no info on an husband or wife in a pedigree tree what is their probability?
Assume the one in the question
What does monogenic inheritance mean?
Phenotypes are influenced by one gene
What is linkage?
What does it result in?
Genes do not show independent assortment during meiosis
Increases the chance that alleles are inherited together
What happens to genes on the same chromosome?
They are linked
