Question

1)Tyrosinemia II and alkaptonuria are both autosomal recessive conditions involving the loss of function of an enzyme in the metabolic pathway that breaks down dietary protein. If a person with tyrosinemia II and a person with alkaptonuria have a child together, what will the phenotype of the child be?

2) Say you have deduced that a particular genetic disorder is caused when the body cannot produce a particular enzyme, encoded by gene ABC. Therefore you compare gene ABC’s nucleotide sequence between healthy people and people who have the disorder (because they do not produce the enzyme). But the DNA nucleotide sequence from the start site of transcription to the termination point of transcription is always exactly the same for people in both groups. If this genetic disorder is caused by a mutation in the DNA, where is the mutation likely to be, and how is the mutation acting to result in these observations? Apart from the enzyme itself, what molecule’s absence from the cells of an affected person would verify this?

3) Suppose you breed fancy cats and cat fur comes in two types: long or short. You discover that when a purebred long-haired cat and a purebred short-haired cat mate, something unusual occurs: all of the female offspring have patches of long hair and patches of short hair. No two female cat look the same. All of the male offspring have fur length that matches their mother's.

Your line of female cats with patchy fur becomes very popular among cat breeders, you continue breeding purebred long-hairs with purebred short-hairs to get the patchy female offspring. After several years and hundreds of kittens, you are to find a cat with a random mix of long and short fur that is male. This is the only patchy male you have seen.

What is unusual about the chromosomes of this male cat?

4) there is one gene that controls leaf shape in holly leaves.

a). If leaf shape is controlled by epigenetic markers, how might epigenetic patterns differ between smooth and prickly leaves?

b) Suppose instead the one gene controlling leaf shape is transcribed in exactly the same amount in prickly leaves as in smooth leaves, how might RNA processing cause the protein's shape to differ between smooth and prickly leaves?

Answer 1

Q1.