Human Karyotypes Quiz

Explanation
During mitosis, the 23 pairs of human chromosomes condense and become visible with a light microscope. This is because the chromosomes, which contain the genetic material of an individual, condense and coil up tightly during mitosis. This condensation allows for easier visualization of the chromosomes under a light microscope, enabling scientists to study their structure and behavior during cell division.

Explanation
The correct answer is 1. This is because the bands located on Giemsa dye chromosomes represent individual genes. It is a common misconception that each band represents multiple genes, but in reality, each band corresponds to a single gene.

Explanation
In the human karyotyping lesson, a total of 3 patient cases were presented.

Explanation
A karyotype is a visual representation of an individual's chromosomes, arranged in pairs according to size and shape. It provides information about the number and structure of chromosomes. The sex of the individual, number of autosomes (non-sex chromosomes), number of sex chromosomes, and placement of the centromere can all be determined from a karyotype. However, the number of Giiemsa bands is not a piece of information obtained from a karyotype. Giiemsa bands refer to specific regions of chromosomes that can be stained and visualized under a microscope. The number of Giiemsa bands is not a standard or commonly used parameter for analyzing karyotypes.

Explanation
The cooperative effort between Zooweb and the University of Wisconsin State Laboratory of Hygiene published each karyotype in three formats. The correct formats are the original unmodified smear, the original with extraneous materials removed, and the chromosomes arranged in standard order. These formats ensure that the karyotypes are presented in their true, unaltered form, while also removing any unnecessary materials and organizing the chromosomes in a standardized manner for easier analysis and comparison.

Explanation
Trisomy-18 is a genetic disorder where an individual has an extra copy of chromosome 18. Normally, humans have 46 chromosomes, but in the case of Trisomy-18, there is an additional copy of chromosome 18, resulting in a total of 47 chromosomes. Therefore, the correct answer is 47.

Explanation
In the karyotyping activity, to form a correct karyotype for patient A, you had to match up 4 chromosomes.

Explanation
The correct sex of patient B is male.

Explanation
A sperm has either an X or a Y chromosome. This is because sperm cells are responsible for determining the sex of an individual during reproduction. If a sperm cell carries an X chromosome, it will result in a female offspring, while a sperm cell carrying a Y chromosome will result in a male offspring. Therefore, the correct answer is that a sperm has an X OR a Y chromosome.

Explanation
This person's karyotype is abnormal because they have an extra autosome. Karyotype refers to the number and appearance of chromosomes in an individual's cells. In a normal karyotype, there should be a specific number of autosomes (non-sex chromosomes) and sex chromosomes. However, in this case, there is an additional autosome present, which deviates from the typical karyotype and makes it abnormal.