Question

Which of the following statements about nondisjunction is true?

A. Nondisjunction leads to increased genetic diversity.
B. Nondisjunction is a normal part of meiosis.
C. Nondisjunction can result in abnormal chromosome numbers.
D. Nondisjunction only affects autosomes.

Answer 1

Nondisjunction, occurring during meiosis, leads to improper chromosome separation, resulting in gametes with abnormal chromosome numbers. This can give rise to conditions like trisomy or monosomy, making option C the correct choice.Thus the correct option is:C. Nondisjunction can result in abnormal chromosome numbers.

Explanation:

Nondisjunction is a phenomenon that occurs during meiosis, the process of cell division that produces gametes (sperm and eggs). It involves the failure of chromosomes to separate properly, leading to an unequal distribution of genetic material. The correct answer is C because nondisjunction can result in abnormal chromosome numbers in the daughter cells.

During meiosis, chromosomes are supposed to separate during the formation of gametes, ensuring that each gamete receives a proper set of chromosomes. However, when nondisjunction occurs, chromosomes may fail to separate, leading to a gamete with an abnormal number of chromosomes. This can result in conditions such as trisomy (an extra chromosome) or monosomy (a missing chromosome).

Contrary to option A, nondisjunction does not lead to increased genetic diversity. In fact, it can lead to genetic disorders and abnormalities. Option B is incorrect because nondisjunction is not a normal part of meiosis; it is an error in the process. Option D is also incorrect because nondisjunction can affect both sex chromosomes and autosomes, not just autosomes.

In summary, the correct answer is C because nondisjunction can indeed result in abnormal chromosome numbers, leading to various genetic disorders in offspring..Thus the correct option is:C. Nondisjunction can result in abnormal chromosome numbers.

Answer 2

Nondisjunction can result in abnormal chromosome numbers, leading to genetic disorders such as Down syndrome, where an extra copy of chromosome 21 is present due to the failure of chromosomes to separate correctly during meiosis. Thus, the correct answer is option C.

Step-by-step explanation:

Nondisjunction refers to the failure of chromosomes to separate properly during cell division, leading to an abnormal distribution of chromosomes in daughter cells. This process commonly occurs during meiosis, resulting in gametes with an abnormal number of chromosomes. For instance, in Down syndrome, an extra copy of chromosome 21 arises from nondisjunction during meiosis, leading to a total of three copies of chromosome 21 (trisomy 21) instead of the usual two copies. This abnormal chromosome number can have significant implications, causing genetic disorders and developmental abnormalities (option C).

Contrary to statement A, nondisjunction does not inherently lead to increased genetic diversity. Instead, it can result in genetic disorders due to the imbalance of chromosome numbers. Additionally, statement B is incorrect; while nondisjunction is a recognized phenomenon in meiosis, it is considered an abnormality rather than a normal part of the process. Finally, statement D is false as well; nondisjunction can affect both autosomes (non-sex chromosomes) and sex chromosomes, leading to abnormalities in their numbers and causing genetic disorders like Turner syndrome or Klinefelter syndrome, which involve sex chromosome nondisjunction.

Understanding the implications of nondisjunction is crucial in genetics and reproductive biology. It underscores the significance of proper chromosome segregation during cell division, highlighting how errors in this process can lead to genetic disorders and abnormalities in offspring. Nondisjunction serves as a notable example of how errors during cell division can have profound consequences on genetic stability and development.