Genetics module

Revision quiz before the first genetics session

Answer true or false to the following statements

1. Alleles are alternative forms of a gene at the same locus
   

2. When drawing a pedigree, a filled in circle is used to denote an affected female.
   
3. The son of a woman with an autosomal dominant disorder has a ½ chance of inheriting the disorder.
   
4. Males and females are affected in equal proportions in autosomal recessive inheritance.
   
5. The healthy sib of a person with an autosomal recessive condition has a risk of ½ of being a carrier.
   
6. A carrier is a healthy person who is a heterozygote for a recessive trait.
   
7. Artificial insemination by donor sperm will greatly reduce the risk of a couple with a baby with a rare autosomal recessive condition having another affected baby.
   
8. A male affected with an X-linked trait cannot transmit the disorder to his sons
   
9. Females are never affected with X-linked recessive diseases.
   
10. In mitochondrial inheritance, affected males never pass the disease onto their children.
    
11. Human chromosome analysis by light microscopy can be performed only on peripheral blood cells.
    
12. There are 45 autosomes in the normal human karyotype
    
13. Reciprocal translocations are rarely inherited.
    
14. Robertsonian translocations are found in 25% cases of Down syndrome.
    
15. The primary purpose of genetic counselling is to reduce the incidence of genetic disease in the population.

Answers