Which of the following conditions is characterized by the presence of ketone bodies in urine, often associated with diabetes mellitus? MCQ with Answer and Explanation

Explanation:
Prokaryotic cells lack membrane-bound organelles such as mitochondria, ER, Golgi, etc. They have a nucleoid region, 70S ribosomes, and typically a single circular chromosome. Thus, the statement that they contain membrane-bound organelles is incorrect.

Explanation:
'Survival of the fittest' was a phrase used by Herbert Spencer but adopted by Darwin to describe natural selection—organisms best adapted to the environment survive and reproduce. Lamarck proposed inheritance of acquired characters, Mendel discovered laws of heredity, De Vries proposed mutation theory. Darwin's theory emphasizes differential reproductive success of variants.

Explanation:
Testosterone, secreted by Leydig cells of the testes, is responsible for the development of male secondary sexual characteristics like facial hair, deepening of voice, and muscle growth. Estrogen and progesterone are female hormones.