Video Transcript
Klinefelter’s syndrome is an example of a syndrome caused by chromosomal abnormalities. Which of the following is a common trait associated with Klinefelter’s syndrome? (A) Infertility, (B) myopia, (C) partial deafness, or (D) cervical cancer.
This question asks about Klinefelter’s syndrome, which is a common example of a chromosomal abnormality. To understand the traits associated with Klinefelter’s syndrome, let’s first review the chromosomes in humans. Generally, humans have 23 pairs of chromosomes, or 46 chromosomes in total. The two chromosomes from the 23rd pair are called the sex chromosomes, as they determine the biological sex of the individual.
There are two types of sex chromosomes: X and Y. If a person has two X chromosomes, they are said to be biologically female. If they have one X and one Y chromosome, they are said to be biologically male. Klinefelter’s syndrome occurs when an individual possesses two X chromosomes and one Y chromosome. This means that instead of 46 chromosomes, people with Klinefelter’s syndrome have 47. People with Klinefelter’s syndrome have male reproductive organs, but the presence of an extra X chromosome causes their testosterone levels to be low. They have decreased sperm production or difficulty producing healthy sperm. Since healthy viable sperm are required for fertilization and pregnancy, people with Klinefelter’s syndrome will generally experience infertility.
Therefore, a common trait associated with Klinefelter’s syndrome is (A), infertility.
