Botany MCQs for NEET — Practice Questions with Answers

Agent Orange is a herbicide and defoliant chemical. It is known for its use by the U.S. military as part of its herbicidal warfare program during the Vietnam War. It contains dioxin, which is harmful to both humans and the environment.

Short-day plants require long periods of darkness to initiate flowering. When a short light period is introduced during the dark period, it disrupts the critical dark period, preventing flowering. This is why the second group of plants did not flower when exposed to a brief light period during the dark phase.

Gibberellins promote seed germination by stimulating the synthesis of hydrolytic enzymes, such as amylase, that break down stored food reserves in the seed into simpler molecules. These simpler molecules are then used for the growth of the embryo, facilitating seed germination.

Gibberellins are a group of plant hormones that play a key role in promoting stem elongation, germination, and flowering. Bolting, which is the rapid elongation of the stem in plants such as lettuce or spinach, is primarily induced by gibberellins.

Cytokinins are a class of plant hormones that are synthesized in the roots and transported to various parts of the plant. They are also found in the endosperm of seeds. Cytokinins promote cell division and growth, and they play a crucial role in plant development.

Indole-3-acetic acid (IAA) is a type of auxin, which is a plant hormone responsible for various growth and behavioral processes in the plant's life cycle. Auxins like IAA are involved in the elongation of cells in the shoot and are particularly influential in the growth of the leaf apex.

A biennial plant can be converted into an annual plant by subjecting its seeds to a cold treatment, a process known as vernalization. This treatment accelerates the flowering process, making the plant complete its life cycle in one year instead of two.

As plants grow, one of the key metrics that increases is the dry weight. Dry weight refers to the mass of the plant minus its water content. As the plant undergoes photosynthesis and produces more biomass, its dry weight naturally increases.

The size of the vacuole increases during the cell elongation phase. During this phase, cells undergo significant growth in their size, and vacuoles take up more water and expand, causing the cell to elongate.