The endoskeleton of the human body is composed mainly of: MCQ with Answer and Explanation

Explanation:
Transcription is the synthesis of mRNA from the DNA template strand by RNA polymerase. It occurs in the nucleus (eukaryotes). Replication is DNA duplication. Translation is protein synthesis from mRNA. Transformation is the uptake of foreign DNA by bacteria. The central dogma: DNA → RNA → Protein. Transcription produces mRNA, tRNA, rRNA. The mRNA carries the codon sequence for protein assembly.

Explanation:
The ball and socket joint (e.g., glenohumeral, hip) allows movement in multiple axes (flexion, extension, abduction, adduction, rotation). The rounded head of one bone fits into the cup-shaped socket of another. Hinge (elbow, knee) allows movement in one plane, pivot (neck) allows rotation, gliding (wrist) allows sliding.

Explanation:
Mature mammalian red blood cells (erythrocytes) lose their nucleus and other organelles during development to maximize space for hemoglobin. Thus they are anucleate. They cannot divide or repair themselves and have a lifespan of about 120 days. Neurons, leukocytes, and hepatocytes are nucleated. RBCs obtain energy through anaerobic glycolysis.