Genetics Quiz: Inheritance Patterns

A condition where an individual has an extra copy of chromosome 13. This results in a total of 47 chromosomes instead of the usual 46.

A type of genetic inheritance where a trait is expressed when only one copy of the associated gene is present. This dominant gene masks the effect of any recessive allele.

A condition where a person has an extra copy of chromosome 21. This leads to a total of 47 chromosomes instead of the usual 46.

The probability of a couple, one of whom is heterozygous for an autosomal recessive mutation and the other homozygous sick, having a sick child is:

The probability of a couple, one of whom is heterozygous for an autosomal recessive mutation and the other homozygous sick, having a sick child is:

A condition where an individual has either more or less than the usual number of chromosomes. This can be due to an extra chromosome or a missing chromosome.

A kind of inheritance where the gene for a certain trait is located on the X chromosome.

The probability of a couple, one of whom is heterozygous for an autosomal recessive mutation and the other homozygous sick, having a sick child is:

A healthy carrier for an autosomal recessive disease carries one copy of the mutated gene and one copy of the normal gene. They don't have the disease themselves but can pass the mutated gene to their offspring.

In a reciprocal balanced translocation, there is an exchange of genetic material between two non-homologous chromosomes. This exchange is balanced because no genetic material is lost or gained. However, it can lead to fertility issues and an increased risk of having children with chromosomal abnormalities.

Klinefelter syndrome is a genetic condition that affects males. It is caused by the presence of an extra X chromosome in addition to the normal XY complement. The karyotype for Klinefelter syndrome is 47, XXY.

Amniocentesis is a prenatal diagnostic procedure that involves taking a sample of amniotic fluid surrounding the fetus. This fluid contains fetal cells that can be analyzed for chromosomal abnormalities and genetic disorders. Amniocentesis is usually performed around the 15th to 20th week of gestation.

When a disease with autosomal dominant inheritance is present in a male subject, there is a 50% chance that his children will inherit the disease from him. This is because the male has one copy of the mutated gene and one copy of the normal gene. Each child has a 50% chance of inheriting the mutated gene from him.

Allelic heterogeneity refers to a situation where different mutations within the same gene are responsible for causing the same disease. This means that different families can have the same disease but with different underlying genetic defects.

Turner syndrome is a genetic condition that affects females. It is caused by the absence of one of the X chromosomes. The karyotype for Turner syndrome is 45, X0.

Consanguinity refers to the marriage between individuals who are related. Consanguineous marriages increase the risk of recessive inheritance conditions. This is because both parents have a higher chance of carrying the same recessive gene, leading to a higher likelihood of their offspring inheriting two copies of the mutated gene.