Genotype
The genetic consiution of an organism
Phenotype
The expression of this genetic constitution and its interaction with the environment
Haploid
One copy of each chromosome
Diploid
Two copies of each chromosome
Heterozygous
Two different alleles
Homozygous
Two of the same allele
Allele
A type of one gene
Example of an allele
Hair- brown or blonde
Eyes- blue or brown etcccc
What are autosomes
They are non-sex chromosomes
How many autosomes are in a human cell
44
What is autosomal linkage
Two genes on the same chromosome
What does autosomal linkage reduce and how
Possible combinations of gametes
What is less likely to happen on autosomal linkage genes when the genes are closer together
The chiasma is less likely to form so they are less likely to cross over
What happens on autosomal linkage genes if the genes are further apart (more likely to happen)
Chiasma is more likely to form and become covalent swapping alleles creating new genes
Why are observed ratios not the same as edxpected
Random fertilisation of gamete’s
What is epistasis
Occurs when the genotype at one gene affects the expression of another gene
what happens if the number is lower than the critical value
you accept the null since results are due to chance
What is the hardy-Weinberg principle used to predict
Allele frequencies in a population
What are the assum[tions of the hardy-Weinberg principle
No mutations or migration
No selective pressures
Infinite population size
What are the Hardy-Weinberg assumptions
No mutations
No migration
No natural selection/ advantageous alleles
Infinite population
Random mating
If there is an autoimmune disease in mice could you assume Hardy-Weinberg assumptions are correct ?
No since those without the disease have an advantageous allele and natural selection occurs
What is disruptive selection
Where the average phenotype is selective against and BOTH extremes are selected
What does disruptive selection usually end in
Speciation / two new species
How do you conclude if disruptive selection has caused speciation
They wont reproduce to fertile offspring
