The amino acid Tryptophan is the precursor for the synthesis of:

A river with an inflow of domestic sewage-rich in organic waste may result in:

Gause’s principle of competitive exclusion states that:

Asthma may be attributed to:

The standard petal of a papilionaceous corolla is also called:

Which of the following is a restriction endonuclease?

It is much easier for a small animal to run uphill than for a large animal, because:

Following are the two statements regarding the origin of life:
(a) The earliest organisms that appeared on the earth were non-green and presumably anaerobes.
(b) The first autotrophic organisms were the chemoautotrophs that never released oxygen.
Of the above statements, which one of the following options is correct?

A cell at telophase stage is observed by a student in a plant brought from the field. He tells his teacher that this cell is not like other cells at telophase stage. There is no formation of cell plate and thus the cell is containing more number of chromosomes as compared to other dividing cells. This would result in:

Depletion of which gas in the atmosphere can lead to an increased incidence of skin cancers: