Which of the following statements about plant reproduction is correct? MCQ with Answer and Explanation

Explanation:
Acetylcholinesterase degrades acetylcholine into acetate and choline, terminating the synaptic signal. Choline acetyltransferase synthesizes ACh, MAO and COMT degrade monoamines.

Explanation:
Down syndrome, the most common chromosomal aneuploidy, is caused by an extra copy of chromosome 21 (trisomy 21), usually from nondisjunction during meiosis. It is characterized by intellectual disability, distinct facial features, and increased risk of certain medical conditions. Monosomy X is Turner syndrome.

Explanation:
Pellagra, with symptoms of dermatitis, diarrhea, and dementia, is due to niacin (B₃) deficiency. Beriberi is B₁ deficiency, anemia can be iron/B₁₂/folate, goiter iodine.