The levels of biodiversity include :

'Species richness contributes to the well being of an ecosystem' was explained through an analogy the rivet popper hypothesis'. The hypothesis was given by :

Which of the following is found in symbiotic association with leguminous plants ?

Which of the following are the salient features of Human Genome project?
(A) The average gene consists of 3000 bases, but sizes vary greatly.
(B) Chromosome 1 has most genes (2968), and the Y has the fewest (231).
(C) The total number of genes is estimated at 30,000- much lower than previous estimates of 80,000 to 1,40,000 genes.
(D) Repetitive sequences are stretches of DNA sequences that are repeated many times, sometimes hundred to thousand times.
Choose the correct answer from the options given below:

Observe the figure and answer the following:


What is the above figure representing?

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:

The rate of biomass production is expressed in terms of __________ to compare the productivity of different ecosystems.

Arrange the following steps of genetically engineered insulin production.
(A) Isolation and purification of the insulin gene from beta cells of the
pancreatic islets
(B) Expression of gene in host cell
(C) Joining the two polypeptides by disulfide bonds
(D) Cloning of insulin gene in Escherichia coli cloning host cell
Choose the correct answer from the options given below:

In a 900 meters race, Ram gives Shyam a start of 150 meters and defeats him by 50 seconds. If the speed of Ram is 4.5 m/sec, then the speed of Shyam is

Which of the following statements are correct?
(A) All of electrostatics is basically a consequence of Coulomb's law and the super position principle.
(B) A change producing the electric field is a test change.
(C) Electric and magnetic fields are regarded as physical entities.
(D) In water molecule centres of positive changes and negative changes do not coincide.
(E) Electrostatic field lines cannot form closed loops.
Choose the correct answer from the options given below :

The radius of the first orbit in Bohr's hydrogen atom is 0.53\(\text{\AA}\). The radius of fourth orbit of this atom will be:

A circular loop of conducting wire is placed near a current carrying wire as shown in the figure. Both are in the same plane. If the current flowing through the wire is suddenly increased.

If \(A\) and \(B\) are independent events, then
A. not \(A\) and not \(B\) are independent
B. \(A\) and not \(B\) are independent
C. not \(A\) and \(B\) are not independent
D. \(P(A \cup B)=P(A)+P(B)\)
E. \(P(A \cap B)=P(A) P(B)\)
Choose the correct answer from the options given below: