RNA interference (RNAi) is a technique used in genetic engineering to silence specific genes. In the development of nematode-resistant transgenic tobacco plants, the source of the silencing RNA was: MCQ with Answer and Explanation

Explanation:
The tricuspid valve has three cusps and prevents backflow of blood from the right ventricle to the right atrium during contraction. The mitral (bicuspid) valve is on the left side. Semilunar valves are at the ventricular outlets.

Explanation:
Charles Darwin, an English naturalist, proposed the theory of evolution by natural selection in his book 'On the Origin of Species'. Gregor Mendel, an Austrian monk, conducted experiments on pea plants and proposed the fundamental laws of inheritance (segregation and independent assortment). Robert Hooke discovered cells in cork tissue; the cell nucleus was discovered later by Robert Brown. Thus, statements 1 and 2 are correct.

Explanation:
Cholera is an acute diarrheal disease caused by the bacterium Vibrio cholerae, typically transmitted through contaminated water and food. Polio (poliomyelitis) is a highly infectious viral disease caused by the poliovirus, which can invade the nervous system and cause paralysis. Ringworm (dermatophytosis) is a common superficial fungal infection of the skin, hair, or nails caused by dermatophytes like Microsporum, Trichophyton, and Epidermophyton. All three statements correctly identify the causative agents.