Genetic Conditions

Front

What is a chromosomal mutation that results in a person having fewer or more than 46 chromosomes?

Back

Nondisjunction is a chromosomal mutation that causes a person to have an abnormal number of chromosomes.

Front

Which genetic disorder is caused by a rare dominant allele?

Back

Huntington's disease is caused by a rare dominant allele.

Front

How many copies of a recessive allele are needed to express a recessive disorder?

Back

You need 2 copies of the recessive allele to express a recessive disorder.

Front

What condition results from having 3 copies of chromosome pair 21?

Back

Down's syndrome results from having 3 copies of chromosome pair 21.

Front

Which disorder is caused by recessive alleles and involves a substitution mutation?

Back

Sickle cell anemia is caused by recessive alleles and a substitution mutation.

Front

What is the definition of a recessive allele?

Back

A recessive allele is an allele that must be present in two copies for its trait to be expressed.

Front

What is the definition of a dominant allele?

Back

A dominant allele is an allele that can express its trait even when only one copy is present.

Front

What is the genetic basis of Huntington's disease?

Back

Huntington's disease is caused by a mutation in the HTT gene, which is inherited in a dominant manner.

Front

What is the significance of nondisjunction in genetic disorders?

Back

Nondisjunction can lead to aneuploidy, resulting in disorders such as Down's syndrome.

Front

What is the inheritance pattern of sickle cell anemia?

Back

Sickle cell anemia is inherited in an autosomal recessive pattern.