1. Here are a few questions to test your knowledge and understanding of the inheritance!

2. Give a genetic ratio of the following a)BB x Bb b)Bb x Bb

3. What is Codominance? Write your answer here: (two lines only!)

4. What type of inheritance does ABO blood group system show: a)Monohybrid inheritance b)Sex-linked c)Multiple alleles d)Codominance e)All f)A and B g)C and D

5. What ratio do you expect in a dihybrid cross in the F2 generation Write answer here: ______________

6. Give an example for monohybrid inheritance, sex-linked inheritance, codominance & incomplete dominance Monohybrid: Sex-Linked: Codominance: Incomplete dominance:

7. Example exam Q. In a pea plant, the allele for purple flowers is dominant over the allele for white flowers. How would you find out if a purple-flowered plant is homozygous or heterozygous?

8. ANSWERS Give a genetic ratio of the following: BB x Bb >> 1:1 Bb x Bb >> 1:2:1 What is codominance? >> Where an organism who is heterozygous where the expression of both alleles is expressed in the phenotype e.g. a flower with an allele for white petals and an allele for red petals will have pink petals as both red and white alleles are dominant. What type of inheritance does ABO bloody group system show >> C and D What ratio do you expect in a dihybrid cross in the F2 generation >> 9:3:3:1

9. ANSWERS CONT.. Give an example for monohybrid inheritance, sex-linked inheritance & codominance a) Fruit fly, normal wings and vestigal wings. (anything that involves one characteristic!!) b) Colour blindness, haemophilia are some examples. c) Roan colour in shorthorn cattle or blood group AB d) Red and white flowers

10. Example exam Q. In a pea plant, the allele for purple flowers is dominant over the allele for white flowers. How would you find out if a purple-flowered plant is homozygous or heterozygous? ANSWER: you would cross it with a homozygous white plant as it will possess the recessive allele. IF the offspring are all purple, the original purple-flowered plant was homozygous because the offspring possess a heterozygous genotype where purple is the dominant allele. However, if the offspring are a mix of purple and white flowers, the original flower was heterozygous because the genotype ratio would be 1:2:1.