In a eukaryotic cell, the site of ribosomal RNA synthesis is the: MCQ with Answer and Explanation

Explanation:
Hans Fischer determined the structure of chlorophyll in the 1930s and synthesized hemin. Willstätter studied its composition, Calvin elucidated the carbon fixation pathway, Woodward synthesized chlorophyll.

Explanation:
The kidneys are the primary excretory organs, filtering blood through nephrons to remove waste products and excess water, forming urine. The liver is a multifunctional organ that produces bile, which is stored in the gall bladder and released into the small intestine to emulsify fats, aiding in their digestion. The spleen is a lymphoid organ involved in filtering blood and immune responses; it does not produce digestive enzymes (the pancreas does). Thus, statements 1 and 2 are correct.

Explanation:
The atlantoaxial joint (between atlas and axis vertebrae) is a pivot joint, allowing rotation of the head ('no' motion). Hinge allows flexion/extension, ball and socket multiaxial, gliding sliding. The odontoid process of the axis acts as a pivot.