Question

Select Subject B from the SIMULATION pane. Complete subject B’s karyotype. Take a snapshot of the completed karyotype, paste it into your document, and label it. Examine the karyotype. Is Subject B a male or female? _____________________________¬ How do you know? _________________________________________________________

Answer 1

Note about the question:

In the GIZMO program, you will be provided with 46 chromosomes that are not paired nor in order (box superior-right). According to the chromosome image shown below, you need to look for the correct chromosomes, pair them with their homologous, and place them in their correct spot to complete the karyotype.

Answer:

• Subject B sex: Female
• Justification: The last pair of chromosomes are equally large, meaning that they are two X chromosomes (XX).

Explanation:

Note: You will find the complete karyotype in the attached files.

A human cell has 46 chromosomes or 23 pairs of homologous chromosomes. 22 of them are somatic chromosomes or not-sex chromosomes. The last pair, number 23, is the only sex pair.    

To know if an individual is a male or a female, you just need to see the last pair of chromosomes. Pair 23 is the sex pair.

• Male: The pair is formed of a short chromosome (which corresponds to Y from the male parent) and a large chromosome (which corresponds to X from the female parent)---> XY

• Female: The pair is formed of two equally large chromosomes. Each of them corresponds to X, one from the male parent and the other from the female parent). ----> XX