Question

downs syndrome
this picture is an example of...
○ nondisjunction.
○ all of these.
○ a karyotype.
○ a mutation.

Explanation:

• A karyotype is a visual representation of an individual's chromosomes. The image shows a karyotype with an extra chromosome 21, which is characteristic of Down's syndrome.
• Nondisjunction is the failure of chromosomes to separate properly during cell division, which can lead to an abnormal number of chromosomes (aneuploidy) as seen in Down's syndrome (trisomy 21).
• A mutation is a change in the DNA sequence. While Down's syndrome can be caused by a mutation (e.g., translocation), the karyotype itself is a direct visualization of the chromosomal abnormality. Since the question is asking what the picture is an example of, and the picture is a karyotype, that is the most direct answer. However, all the options (mutation, karyotype, nondisjunction) are related to Down's syndrome in different ways. But when specifically referring to the "picture" (which is a karyotype image), the most accurate answer based on the visual representation is a karyotype.

Answer:

a karyotype.