The correct answer is:(a) Suberin. Cork cells are made impervious to water and gases due to the presence of suberin, a hydrophobic substance that forms a protective barrier, preventing water loss and providing resistance to microbial attack. Class 9th Science ...

The correct answer is:(d) remain at the same position. Trees grow from their tips (both at the roots and shoots), not by stretching upwards from the base. So, the nail will stay at the same height, though it might get ...

The correct answer is:(b) Collenchyma. Commercial fibers like jute and flax are derived from the collenchyma tissue, which provides mechanical support and flexibility to plants. These fibers are obtained from the stem and are widely used in making ropes, bags ...

The correct answer is:(c) Companion cells Companion cells, which are found in the phloem of vascular plants, retain their nucleus at maturity. They play a crucial role in supporting sieve tube elements, which lose their nucleus at maturity but remain ...

The correct answer is:(d) Limbs. Voluntary muscles, also known as skeletal muscles, are found in the limbs and are under conscious control, allowing for movement of body parts. Class 9th Science NCERT MCQ Questions NCERT Books MCQ Questions Session 2024-2025.