Down's Syndrome is a result of which genetic condition?

Down's Syndrome is a result of which genetic condition?

• A. An extra chromosome from trisomy 21
• B. A deletion of a chromosome
• C. An inherited recessive gene mutation
• D. A dominant gene on chromosome 15

Answer: (A)

Down's Syndrome, also known as Trisomy 21, occurs when an individual has an extra copy of chromosome 21. This results in three copies of this chromosome rather than the typical two, which leads to the distinct physical characteristics and developmental challenges associated with the syndrome. The additional genetic material is a key factor in the condition's effects on growth and cognitive development. In contrast, other conditions mentioned in the options involve different genetic mechanisms, such as deletions or mutations of genes, which do not correspond to the chromosomal abnormality seen in Down's Syndrome. A deletion of a chromosome would typically lead to a different set of symptoms and conditions rather than Trisomy 21. Likewise, inherited recessive gene mutations or dominant genes on other chromosomes do not play a role in the occurrence of Down's Syndrome. Therefore, the presence of an extra chromosome from trisomy 21 is the correct basis for understanding this genetic condition.

Down's Syndrome, also known as Trisomy 21, occurs when an individual has an extra copy of chromosome 21. This results in three copies of this chromosome rather than the typical two, which leads to the distinct physical characteristics and developmental challenges associated with the syndrome. The additional genetic material is a key factor in the condition's effects on growth and cognitive development.

In contrast, other conditions mentioned in the options involve different genetic mechanisms, such as deletions or mutations of genes, which do not correspond to the chromosomal abnormality seen in Down's Syndrome. A deletion of a chromosome would typically lead to a different set of symptoms and conditions rather than Trisomy 21. Likewise, inherited recessive gene mutations or dominant genes on other chromosomes do not play a role in the occurrence of Down's Syndrome. Therefore, the presence of an extra chromosome from trisomy 21 is the correct basis for understanding this genetic condition.