How many autosomes are in this human karyotype? How many sex chromosomes?
The correct answer and explanation is:
A human karyotype consists of 46 chromosomes, which are organized into 23 pairs. Out of these, 22 pairs are autosomes, and the remaining pair consists of sex chromosomes.
Autosomes are chromosomes that are not involved in determining the sex of an individual. These chromosomes contain genes that determine various traits and functions in the body, such as eye color, hair color, and the ability to process certain biochemical substances. In a human karyotype, there are 22 pairs of autosomes, which accounts for 44 chromosomes.
The sex chromosomes, on the other hand, are responsible for determining the biological sex of an individual. There are two types of sex chromosomes: X and Y. Females typically have two X chromosomes (XX), while males have one X and one Y chromosome (XY). The sex chromosomes are the 23rd pair in the karyotype, so there are two sex chromosomes in total, either XX or XY, depending on the individual’s sex.
To summarize, in a human karyotype:
- There are 22 pairs of autosomes, totaling 44 autosomes.
- There is 1 pair of sex chromosomes, either XX or XY, totaling 2 sex chromosomes.
The total number of chromosomes in a human karyotype is always 46, with 44 autosomes and 2 sex chromosomes. This structure is typical for individuals with typical male or female karyotypes, though variations such as in individuals with Turner syndrome (45 chromosomes, one X chromosome) or Klinefelter syndrome (47 chromosomes, XXY) can occur. These exceptions are a result of abnormalities in the distribution of sex chromosomes.