Biology MCQs

Notes:
Abscisic Acid plays the most important role in establishing dormancy in seeds. Abscisic Acid has also been found to be present in metazoans, from sponges up to mammals including humans.

Notes:
Cloves are aromatic dried flower buds of a tree. Cloves are native to Indonesia and used as a spice in cuisines all over the world. Cloves are now harvested primarily in Indonesia, Madagascar, Zanzibar, Pakistan, and Sri Lanka; they are also grown in India under the name Lavang.

Notes:
The gymnosperms, also known as Acrogymnospermae, are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes. Pinus gerardiana, known as the chilgoza pine is a king of Gymnosperm.

Notes:
Turmeric is a product of Curcuma longa, a rhizomatous herbaceous perennial plant belonging to the ginger family Zingiberaceae. They are native to tropical South Asia. There are 133 species of Curcuma all around the world.

Notes:
A treatment with abscisic acid would prevent water loss from the plant leaves, by reducing transpiration, in times of low water availability.

Notes:
Cleviceps purpurea is an important ascomycete that grows on the grains of rye grass cereals. It produces the drug ergot, which is both a severe poison and a useful medicinal drug. It affects the central nervous system as well as causes the contraction of involuntary muscle. Ergotism, caused by eating infected rye bread, was common in the Middle Ages, when it was known as “St. Anthony’s Fire.

Notes:
Tissue culture is the growth of tissues or cells in an artificial medium separate from the organism. It refers to the culture of animal cells and tissues, with the more specific term plant tissue culture being used for plants. The term “tissue culture” was coined by American pathologist Montrose Thomas Burrows.

Notes:
Water is passively transported into the roots and then into the xylem. The forces of cohesion and adhesion cause the water molecules to form a column in the xylem. Water moves from the xylem into the mesophyll cells, evaporates from their surfaces and leaves the plant by diffusion through the stomata.

Notes:
Insulin and glucagon are hormones secreted by islet cells within the pancreas. They are both secreted in response to blood sugar levels, but in opposite fashion. Insulin is normally secreted by the beta cells of the pancreas. Glucagon raises blood glucose levels by stimulating the liver to metabolize glycogen into glucose molecules and to release glucose into the blood.  Insulin is a hormone that regulates blood sugar levels.

Notes:
Hybridization is beneficial for improvement in crop production as the Hybrid variety of crops have some special characteristics like good resistance to diseases, improved yield, etc. so they are often sought to have a high production.