The shape of a bacterial chromosome is typically: MCQ with Answer and Explanation

Explanation:
Vitamin A (retinol) is converted to retinal, which combines with opsin to form rhodopsin, the light-sensitive pigment in rod cells of the retina. Deficiency leads to night blindness and xerophthalmia. Carrots and liver are rich sources. Vitamin C is ascorbic acid, D is calciferol, E is tocopherol.

Explanation:
In 1944, Oswald Avery, Colin MacLeod, and Maclyn McCarty conducted a landmark experiment building on Griffith's transformation experiment. They purified various macromolecules (DNA, RNA, proteins, lipids) from the virulent S strain of Streptococcus pneumoniae and tested which one could transform the non-virulent R strain into the virulent form. They found that only DNA could cause transformation, and this activity was destroyed by DNase but not by RNase or proteases. This provided the first strong, direct evidence that DNA, not protein, is the genetic material.

Explanation:
UV radiation can induce mutations; germline mutations are passed on. Not all mutations change protein sequence (silent mutations). So 2 is incorrect.