Which plant tissue is responsible for the transport of organic nutrients?
A. Collenchyma
B. Sclerenchyma
C. Xylem
D. Phloem
Answer: Option D
Solution (By JKSSB Mock Tests)
Phloem transports organic solutes (mainly sucrose) from source (leaves) to sink (roots, fruits) in a process called translocation, using sieve tubes and companion cells. Xylem transports water and minerals from roots upwards. Collenchyma and sclerenchyma are mechanical tissues providing support. Phloem is alive at maturity, while xylem vessels are dead. Companion cells regulate sieve tube activity.
Explanation:
Kidneys are bean-shaped organs that filter waste products, excess water, and electrolytes from the blood to form urine. The liver processes nutrients and toxins, the heart pumps blood, the lungs exchange gases.
Consider the following statements regarding mitochondria:
1. They are double-membrane organelles.
2. They have their own 80S ribosomes.
3. They are the site of aerobic respiration.
Which of the statements is/are correct?
Explanation:
Mitochondria have two membranes (outer and inner) and are the site of Krebs cycle and oxidative phosphorylation. They possess 70S ribosomes, not 80S. Hence, statements 1 and 3 are correct.
Explanation:
The vocal cords (folds) in the larynx vibrate as air passes, producing sound. Pitch is controlled by tension. Epiglottis prevents food entry, trachea is airway.
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