A small standing crop of phytoplankton supports a large standing crop of zooplankton. This can be correctly represented by:

In RNAi genes are silenced by:

Which one of the followings is an auto-immune disease?

Read the following passage carefully and answer the given questions.
Insulin consists of two short polypeptide chains- chain A and chain B, that are linked together by disulphide bridges. Some strains of Bacillus thuringiensis produce proteins that kill certain insects such as lepidopterans, coleopterans and dipterans. Bt toxin protein is converted into an active form of toxin due to the alkaline pH of the gut which solubilise the crystals. Transgenic animals that produce useful biological products can be created by the introduction of the portion of DNA (or genes) which codes for a particular product such as human protein (alpha-1-antitrypsin) used to treat emphysema. Plants, bacteria, fungi and animals whose genes have been altered by manipulation are called Genetically Modified Organisms (GMO). GM plants have been useful in many ways. Genetic modification has: (i) made crops more tolerant to abiotic stresses. (ii) reduced reliance on chemical pesticides (pest-resistant crops). (iii) helped to reduce post harvest losses. (iv) increased efficiency of mineral usage by plants (this prevents early exhaustion of fertility of soil). (v) enhanced nutritional value of food.
Transgenic animals that produce useful biological products such as human protein (alpha-1-antitrypsin) used to treat the disorder:

The region where the body of the ovule fuses with funicle is known as:

Which one of the following diagnostic techniques is based on the principle of antigen-antibody interaction?

We use microbes and microbially derived products almost every day. Bacteria called lactic acid bacteria (LAB) grow in milk to convert it into curd. The dough, which is used to make bread, is fermented by yeast called Saccharomyces cerevisiae. Microbes are used to produce industrial products like lactic acid, acetic acid and alcohol, which are used in a variety of processes in the industry. However, certain bacteria, which grow anaerobically on cellulosic material, produce large amount of methane along with CO2 and H2. These bacteria are collectively called methanogens, and one such common bacterium is Methanobacterium. These bacteria are commonly found in the anaerobic sludge during sewage treatment. Microbes are also used for commercial and industrial production of certain chemicals like organic acids, alcohols and enzymes.
Examples of acid producers are Aspergillus niger (a fungus) of citric acid. You are familiar with the commonly used antibiotic Penicillin. Do you know that Penicillin was the first antibiotic to be discovered, and it was a chance discovery? Statins produced by the yeast Monascus purpureus have been commercialised as blood-cholesterol lowering agents. It acts by competitively inhibiting the enzyme responsible for synthesis of cholesterol.
Which one of the following statements is not true with respect to microbes?

Two solenoids of equal number of turns having their lengths and radii in the same ratio \(1: 3\). The ratio of their self inductances \(L _{ 1 }: L _{ 2 }\) will be :

Phytophagous insects feed on :

Answer the question on the basis of passage given below :
Living systems are made up of various complex bio-molecules like carbohydrates, proteins, nucleic acids, lipids etc. Proteins and carbohydrates are essential constituents of our food. Carbohydrates are primarily produced by plants and form a very large group of naturally occurring organic compounds. Some common examples are cane sugar, glucose, starch etc.
Carbohydrates are stored in animals as:

Identify the correct statement for the species diversity.

The negatively charged DNA is wrapped around the positively charged histone octamer and forms a structure, called:

Read the following features of the Photoelectric effect.
(A) The maximum kinetic energy of the photoelectrons varies linearly with the frequency of incident radiation
(B) The maximum kinetic energy of the photoelectrons is dependent on its intensity.
(C) For a frequency of incident radiation, lower than the cut-off frequency, photoelectric emission is possible even if the intensity is not large.
(D) Ultraviolet light can eject photoelectrons from copper even if visible light does not eject
Choose the correct answer from the options given below: