Topic 7 Inheritance Flashcards
What is a genotype
The genetic constitution of an organism
What is the phenotype
The expression of the genes and it’s interaction with the environment
What is homozygous
A pair of homologous chromosomes carrying the same alleles for a single gene
What is heterozygous
A pair of homologous chromosomes carrying 2 different alleles for a single gene
What is a recessive allele
An allele only expressed if no dominant allele is present
What is a dominant allele
An allele that will always be expressed in the phenotype
What does co dominant mean
Both alleles are equally dominant and expressed in the phenotype
What is sex linkage
A gene whose locus is on the X chromosome
What is autosomal linkage
Genes that are located on the same chromosome (not sex chromosome)
What is epistsis
When one gene modified or masks the expression of a different gene at a different locus
What is mono hybrid
Genetic inheritance cross of characteristics determined by one gene
What is dihybrid
Genetic inheritance cross for a characteristic determined by 2 genes
How would you write a sex linkage genetic diagram
Chromosome and then the allele
What type of allele is cystic fibrosis caused by
Recessive
If 2 carriers of CF reproduce what is the probability they have a girl with cystic fibrosis
So the parental genotypes would be Ff and Ff so there would be a 25% chance of child with CF but if it’s a girl there’s 50% chance so you’d do 25% x 50% = 12.5%
What is the ratio of a dihybrid cross with 2 heterozygous parents
9:3:3:1
If autosomal linkage has occurred what is the ratio for dihybrid cross
3:1
What is chi squared
The statistic to investigate differences between frequencies
What is the null hypothesis
There is no significant difference between the expected and observed frequency of …