Arrange the following events of Meselson and Stahl's experiment in order of their occurence:
A. DNA extracted from the culture, twenty minutes after transfer from 15N to 14N medium had a hybrid density.
B. E. Coli with heavy DNA were transferred into a medium with 14NH4CI. Coli were grown in a medium containing 15NH4CI.
C. E.
D. DNA extracted from the culture after forty minutes had equal amounts of hybrid DNA and light DNA.
Choose the correct answer from the options given below:

The number of chromosomes in the gamete of a house fly is:

Observe the figure and answer the following:


Identify the true statements:
A. Stable genetic equilibrium results in evolution
B. Genetic equilibrium means the constant gene pool in population remains constant
C. In a given population one can find out the frequency of occurrence of alleles of a gene or a locus
D. The frequency of occurrence of alleles of a gene remain same through generations
Choose the correct answer from the options given below:

Parturition is the:

Read the Passage carefully and answer the the questions
The DNA fragments can be separated by a technique known as gel electrophoresis. Since DNA fragments are negatively charged molecules, they can be separated by forcing them to move towards the anode under an electric field through a medium/matrix. The separated DNA fragments can be visualised only after staining the DNA with a compound known as ethidium bromide followed by exposure to UV radiation. The repeated amplification of DNA is achieved by the use of a thermostable DNA polymerase (isolated from a bacterium, Thermus aquaticus). After completion of the biosynthetic stage, the product has to be subjected through a series of processes before it is ready for marketing as a finished product. The downstream processing and quality control testing vary from product to product. The convention for naming restriction enzymes is the first letter of the name comes from the genus and the second two letters come from the species of the prokaryotic cell from which they were isolated.
The thermostable DNA polymerase is isolated from -

Identify the statements which are incorrect with respect to ribosomes
(A) Ribosome translates the mRNA from its 3' to 5' end.
(B) In its inactive state, ribosome exists as two separate subunits.
(C) The mRNA moves between the two subunits of ribosomes during protein synthesis.
(D) Ribosome consists of messenger RNA and 70 different proteins.
Choose the incorrect answer from the options given below:

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 have not evolved to become regulators because:

Nitrogen in trimethylamine is \No Solution(\mathrm{sp}^3\) hybridized. The C-N-C bond angle is \(108^{\circ}\). The geometry of trimethylamine is

Disturbance in the value of allele frequency in Hardy Weinberg equilibrium is directly proportional to the:

Choose the appropriate term for the rate of formation of new organic matter by consumers:

Arrange the following alcohols in increasing order of their boiling points.
(A) Propan-1-ol
(B) Butan-2-ol
(C) Butan-1-ol
(D) Pentan-1-ol
Choose the correct answer from the options given below:

Correct increasing order of wavelength of absorption in visible region for complex is
A. \(\left[ Ni ( CN )_6\right]^{4-}\)
B. \(\left[ Ni \left( H _2 O \right)_8\right]^{2+}\)
C. \(\left[ Ni ( CO )_0\right]^{2+}\)
D. \(\left[ Ni \left( NH _3\right)_6\right]^{2+}\)
Choose the correct answer from the options given below:

The kinetic energy of an electron in the ground state of a hydrogen atom is K . The values of its potential energy and total energy respectively are :