Consider the following statements about the plant root: 1. Root hairs increase absorption surface area. 2. The root cap protects the root tip. 3. The zone of elongation is responsible for root growth in length. Which of the above is/are correct? MCQ with Answer and Explanation
Consider the following statements about the plant root:
1. Root hairs increase absorption surface area.
2. The root cap protects the root tip.
3. The zone of elongation is responsible for root growth in length.
Which of the above is/are correct?
A. 1 and 3 only
B. 2 and 3 only
C. 1 and 2 only
D. 1, 2, and 3
Answer: Option D
Solution (By JKExamLibrary)
All are correct: root hairs absorb water/minerals; root cap protects meristem; elongation zone extends the root.
Explanation:
Vitamin K-dependent carboxylation allows prothrombin and other clotting factors to bind calcium and participate in coagulation. Deficiency prolongs clotting time.
Explanation:
Tissue culture (micropropagation) involves growing plant cells/tissues on a sterile nutrient medium to regenerate whole plants, producing clones. Hybridization is crossing varieties, cross-pollination is natural or artificial pollination, selective breeding chooses parents.
Explanation:
Leptin is a peptide hormone produced primarily by adipocytes (fat cells). Its concentration in the blood is proportional to the amount of body fat. Leptin acts as a satiety signal, crossing the blood-brain barrier to act on receptors in the hypothalamus. It suppresses appetite (anorexigenic effect) and increases energy expenditure, thereby regulating long-term food intake and body weight. It is often called the 'satiety hormone' or 'fat hormone'.
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