Consider the following statements about mutations: 1. Mutations can be caused by UV radiation. 2. All mutations result in a change in the protein sequence. 3. Mutations in germ cells are heritable. Which of the above is/are correct? MCQ with Answer and Explanation

Explanation:
Genetic engineering involves the direct manipulation of an organism's genome, often used to create transgenic organisms that contain foreign DNA (transgenes) for desired traits. Cloning is the process of producing genetically identical copies of a biological entity, ranging from genes to entire organisms. Tissue culture (micropropagation) is widely used for the rapid, large-scale propagation of plants from small explants in a sterile medium; it is not exclusively or primarily used for animal cloning. Thus, statements 1 and 2 are correct.

Explanation:
PCR involves repeated cycles of high-temperature denaturation (around 94°C) to separate the DNA strands. Normal DNA polymerases would be destroyed at these temperatures. Therefore, a thermostable DNA polymerase is required. Taq polymerase, isolated from the thermophilic bacterium Thermus aquaticus found in hot springs, is the most commonly used enzyme because it can withstand the high denaturation temperatures without losing its activity, eliminating the need to add fresh enzyme after each cycle.

Explanation:
The most unique and defining characteristic of Class Aves (birds) is the presence of feathers, which are modified scales used for flight and insulation. Birds are warm-blooded (homeothermic), have a four-chambered heart, and possess a beak instead of jaws. Mammary glands and external pinnae are features of mammals.