The junction between two neurons where neurotransmitters are released is the: MCQ with Answer and Explanation

Explanation:
Sickle cell anemia is an autosomal recessive disorder caused by a single nucleotide substitution (GAG → GTG) in the β-globin gene, resulting in glutamic acid replaced by valine, producing abnormal hemoglobin S. Under low oxygen, HbS polymerizes, distorting RBCs into sickle shape, causing pain and organ damage.

Explanation:
Ribosomes are dense, spherical, non-membranous structures composed of RNA and proteins. They are the cellular factories for protein synthesis. Prokaryotic ribosomes are 70S (50S + 30S subunits), while eukaryotic cytoplasmic ribosomes are 80S (60S + 40S subunits). Therefore, statements 1 and 3 are correct, but statement 2 is false.

Explanation:
Salivary amylase (ptyalin) initiates starch digestion in the mouth, hydrolyzing it into maltose and dextrins. Pepsin digests protein, lipase fats, rennin curdles milk. Amylase works optimally at neutral pH.