Intermediate Inheritance
Short answer questions
1. If a normal human cell has 46 chromosomes, how many chromosomes are passed onto an
offspring from the mother?
2. What is an allele? How is it different from a gene?
3. Mary has wavy hair which is the result of her having one straight hair allele and one curly hair
allele. Explain using a diagram for meiosis why her children could end up with straight hair, curly
hair or wavy hair.
Determining inheritance questions
For the following question, use S for the straight hair allele, C for curly hair allele. Consider that
straight hair and curly hair follow intermediate inheritance.
Peter has curly hair. If Peter's Father had wavy hair, what hair gene was in the sperm which
produced Peter? _______
What is Peter's genotype? _______
Susan has wavy hair. What is her genotype? ______
Peter and Susan have a son, John, who has wavy hair. What hair gene did Susan give him? _______
Their daughter, Katie, has curly hair. What gene was in the egg which was used to produce Katie?
_______
If Katie has a child with a man with straight hair, what are the possible genotypes of the child?
_____________________________
What will the phenotype(s) of these children be? ___________________________
A black rat mates with a grey rat. Use W and B for white and black coat alleles.
What are the possible genotypes of the F1? _____________________
What percentage would you expect to have
a) black coat
b) white coat
c) grey coat
The rat pair has a litter of four baby rats. How many will have black coat, white coat and grey coat?