The hormone responsible for the male secondary sexual characteristics is:
A. Prolactin
B. Testosterone
C. Progesterone
D. Estrogen
Answer: Option B
Solution (By JKExamLibrary)
Testosterone, produced by Leydig cells in the testes, promotes development of male characteristics like facial hair, deepening of voice, and muscle growth. It also regulates spermatogenesis.
Explanation:
Lateral meristems—vascular cambium and cork cambium—are responsible for secondary growth, increasing the girth (diameter) of dicot stems and roots. Apical meristem at root and shoot tips causes primary growth in length. Intercalary meristem at nodes helps in elongation in grasses. Epidermis is a protective outer layer. Secondary growth is absent in most monocots due to lack of vascular cambium.
Consider statements about the cytoskeleton: 1. Microtubules are made of tubulin. 2. Microfilaments are made of actin. 3. Intermediate filaments are made of cellulose. Which are correct?
Explanation:
The cytoskeleton provides structural support and is composed of three main types of filaments. Microtubules are hollow tubes made of the protein tubulin. Microfilaments are solid rods composed of actin. Intermediate filaments are made of various fibrous proteins like keratin, not cellulose, which is a plant cell wall component. Thus, statements 1 and 2 are correct.
Explanation:
Ion exchange chromatography separates proteins based on their net surface charge; positively charged proteins bind to cation exchangers, negatively to anion exchangers. Gel filtration separates by size, affinity by specific binding, SDS-PAGE by molecular weight.
No comments yet. Be the first to start the discussion!