AP BIOLOGY

Detailed explanation-1: -However, because of nondisjunction, an egg cell or a sperm cell can also end up with an extra copy of the X chromosome. If an egg cell with an extra X chromosome (XX) is fertilized by a sperm cell with one Y chromosome, the resulting child will have Klinefelter syndrome.

Detailed explanation-2: -What Causes Klinefelter Syndrome? Boys who have Klinefelter syndrome are born with it. It’s also called XXY because they have an extra X chromosome in most or all their cells. Usually, a person has 46 chromosomes in each cell, divided into 23 pairs, which includes two sex chromosomes.

Detailed explanation-3: -Nondisjunction is the miss segregation of a homologous pair of chromosomes during meiosis (figure 1). It leads to the formation of a new cell with an abnormal amount of genetic material. A number of clinical conditions are the result of this type of chromosomal mutation.

Detailed explanation-4: -Klinefelter syndrome (KS), also known as 47, XXY, is an aneuploid genetic condition where a male has an additional copy of the X chromosome. The primary features are infertility and small, poorly functioning testicles.

Detailed explanation-5: -Klinefelter syndrome is a common genetic condition where a male is born with an extra X chromosome. Typically, a male has one X and one Y chromosome. People with Klinefelter syndrome can experience breast growth, breast cancer, osteoporosis, infertility and learning difficulties.