Biotechnology & Genetic Engineering

Statement 1 is correct: Plants produced by vegetative propagation are exact copies of the parent plant, as they're produced from a single parent. Statement 2 is incorrect: Vegetative propagation may not eliminate viruses. If a virus is present in the parent plant, it will likely be passed on to the new plants as well. Statement 3 is correct: Vegetative propagation can be practised most of the year.

Root hairs are extremely delicate, whether on a tree or a seedling. When transplanting young trees from a nursery to a woodland, damage to the roots and root hairs often leads to the death of a tree.

Statement 1 is correct: Mycorrhizae: - Greatly increase the effective root surface area - Improve water absorption - Help plants withstand drought stress Statement 2 is correct: Mycorrhizal fungi help plants: - Grow in acidic or alkaline soils - Access nutrients even when pH reduces their availability Statement 3 is correct: Mycorrhizae offer bioprotection: - Compete with soil pathogens - Produce antibiotics - Strengthen plant immune responses

All the given minerals have a role in the contraction of muscles in the human body. Calcium: Calcium is essential for activating enzymes that cause muscle contraction. Iron: Iron helps support continued muscle function by supporting energy production in your muscle cells so that muscle fibers always have the energy they need to contract properly. Iron also helps muscles store oxygen to fuel muscle contractions and promotes healthy circulation so that muscles can get additional oxygen from the bloodstream. Sodium: One needs sodium for muscle contraction because it balances potassium to maintain membrane potential.

Statement 1 is correct: Recombinant DNA technology allows genes to be transferred between different plant species to develop desired traits. Statement 2 is correct: Genes from animals can be inserted into plants (e.g., Bt toxin genes from bacteria into plants, or other examples in research), so cross-kingdom gene transfer is possible. Statement 3 is correct: Microbial genes are routinely transferred to higher organisms, such as insulin gene from bacteria to humans for production. Therefore, all three statements are correct.

Aflatoxins are poisonous carcinogens that are produced by certain moulds (Aspergillus flavus and Aspergillus parasiticus), which grow in soil, decaying vegetation, hay, and grain.

Fruits remain biologically active even after harvesting. They continue to undergo respiration, a metabolic process in which stored sugars are broken down to release energy. This respiration accelerates ripening and eventual spoilage. Cold storage works primarily by lowering temperature, which slows down enzymatic and metabolic processes inside the fruit. As temperature decreases, the rate of respiration decreases, delaying ripening and reducing microbial activity. This significantly increases the storage life of fruits.