Drosophila melanogaster was chosen by Thomas Hunt Morgan for the experimental verification of the chromosomal theory of inheritance because of its:
(A) Many types of hereditary variations visible under a low-powered microscope
(B) Large number of progeny in single mating
(C) Clear differentiation of sexes
(D) Life cycle of about 4 weeks
Choose the correct answer from the options given below:

Arrange the given geological periods according to their occurrence from oldest to latest order?
(A) Devonian
(B) Cretaceous
(C) Triassic
(D) Carboniferous
Choose the correct answer from the options given below:

Appearance of resistant organisms in a time scale of months or years, by the excessive use of antibiotics is an example of which of the following?

Read the passage carefully. Attempt the questions.
An overwhelming majority (99 per cent) of animals and nearly all plants cannot maintain a constant internal environment. Their body temperature changes with the ambient temperature. In aquatic animals, the osmotic concentration of the body fluids change with that of the ambient air and water osmotic concentration. These animals and plants are simply conformers. Considering the benefits of a constant internal environment to the organism, we must ask why these conformers had not evolved to become regulators. Recall the human analogy we used above; much as they like, how many people can really afford an air conditioner? Many simply 'sweat it out' and resign themselves to suboptimal performance in hot summer months. Very small animals are rarely found in polar regions. During the course of evolution, the costs and benefits of maintainin a constant internal environment are taken into consideration. Some species have evolved the ability to regulate, but only over a limited range of environmental conditions, beyond which they simply conform.
If the stressful external conditions are localised or remain only for a short duration, the organism has five other alternatives for survival.
Conformers are the animals whose body temperature:

Multiple additions of new genes or alleles to the new population and their loss from the old population of a particular place due to migration is known as:

Which one of the followings is a hormone releasing IUD?

Nicotine stimulates the adrenal gland to release:
(A) Thyroid stimulating hormone (TSH)
(B) Adrenaline
(C) Estrogen
(D) Nor-adrenaline
Choose the correct answer from the options given below:

Eight identical spherical drops, each having a potential of 9 V are combined together to form a single large drop. The potential of this large drop will be :

The area of the parallelogram determined by the vectors \(\hat{i}+2 \hat{j}+3 \hat{k}\) and \(3 \hat{i}-2 \hat{j}+\hat{k}\) is

Maximize \(z=2 x-y\)
Subject to constraints
\(x+y \leq 4, \quad x+3 y \leq 6, \quad x \geq 0, \quad y \geq 0 .\)
The corner points of the feasible region are:

Identify the incorrect statement about the \(H _2- O _2\) fuel cell from the following:

In the course of evolution, life forms on earth tend to move from

Which of the following hormone is released by pancreas and regulates body metabolic pathway?