Inheritance

Question 1

Define Genotype

Answer 1

the genetic constitution of an organism

Question 2

Define Phenotype

Answer 2

the appearance of a characteristic due to expression of the genotype and its interaction with the environment

Question 3

What are Alleles

Answer 3

different forms of the same gene

Question 4

what is a dominant allele

Answer 4

an allele that is always expressed in the phenotype

Question 5

what is a recessive allele

Answer 5

an allele that is only expressed when the genotype is homozygous recessive (two of them are present)

Question 6

what are Co-Dominant alleles

Answer 6

where both alleles are expressed in the phenotype

Question 7

what does sex linkage mean

Answer 7

where the gene is carried on only one type of sex chromosome (usually the X chromosome)

Question 8

what are autosomal chromosomes

Answer 8

the non-sex chromosomes

Question 9

what are autosomal linked genes

Answer 9

• genes that are present in the same chromosome at different loci

Question 10

describe why autosomal linked genes leads to a much higher proportion of certain phenotypes than others?

Answer 10

• autosomal linked genes are more likely to be inherited together as there is no independent assortment and therefore fewer genetic combinations of alleles
• there will be a lower proportion of other phenotypes due to the rare occurrence of crossing over producing recombinant alleles

Question 11

what is Epistasis?

Answer 11

• when the allele of one gene affects or masks the expression of another gene at another locus

Question 12

when is a chi squared test used?

Answer 12

• used when we have categoric data and to compare the observed and expected ratios of the phenotypes of offspring