The cells that synthesise this polypeptide was exposed to a mutagen that caused a substitution mutation that changed the DNA base sequence in the following way:
CATACTTGGCCA
Using the table from part a), explain the effect this mutation will have on the polypeptide produced.
Cri du chat syndrome is a rare genetic disorder caused by a chromosomal abnormality that occurs very early in embryonic development. Babies born with cri du chat syndrome suffer from a variety of symptoms and have a characteristic cry which sounds like the meowing of a cat.
The karyograms below compare the karyotype of a normal child with one that suffers from cri du chat syndrome.
Contrast the karyotype of a normal child with that of a child suffering from cri du chat syndrome.
Two genes, SEMA5A and CTNND2, are believed to be involved with brain development in a foetus. These genes are missing from children suffering from cri du chat syndrome.
Suggest two possible symptoms of children with cri du chat syndrome as a result of this.
Based on your knowledge of chromosomes, suggest a reason why the genome size of a species does not always seem to correlate with the chromosome number.
Wilson's disease is a condition caused by a mutation of gene ATP7B located on chromosome 13, which codes for an ion transport enzyme. This enzyme is responsible for transporting copper ions (Cu2+) into bile so that it can be removed from the body through the digestive tract. There are several mutations which may lead to Wilson's disease; one of these mutations involves the replacement of the amino acid histidine by glutamine.
Describe the type of mutation that could have led to this disease.
People suffering from Wilson's disease have high levels of free copper in their bloodstream which have been shown to cause damage to the cell membranes of red blood cells.
