CAM plants adapt to arid conditions by: MCQ with Answer and Explanation

Explanation:
Cutin, along with waxes, forms the cuticle on the epidermis of leaves and stems, reducing water loss and providing protection. Lignin strengthens cell walls, cellulose is the wall polysaccharide, suberin is in cork cells and root endodermis.

Explanation:
The skin and mucous membranes form the first line of defense (innate immunity), acting as physical barriers that prevent pathogens from entering the body. White blood cells (leukocytes), including phagocytes and lymphocytes, are the cellular components of the immune system that identify, attack, and destroy pathogens. Antibiotics are drugs designed to kill or inhibit the growth of bacteria; they are completely ineffective against viruses, which lack the cellular machinery targeted by antibiotics. Thus, statements 1 and 2 are correct.

Explanation:
The cuticle is a waxy, water-repellent layer secreted by epidermal cells on the outer surface of leaves and young stems. It minimizes water loss through transpiration. Its thickness varies with plant species and habitat; xerophytes often have a thick cuticle. The epidermis is the tissue layer, palisade and spongy mesophyll are photosynthetic tissues.