Test: Biology - 2 - UPSC MCQ

Aflatoxins are produced by many species of Aspergillus, a fungus. Aspergillus Flavus and Aspergillus parasiticus are weedy moulds that grow on a large number of substrates, particular under high moisture conditions.

To inhibit water loss or to conserve water most of the desert species have waxy leaves that keep them water proof when stomata are closed. Water is further conserved by reducing surface area so most succulents have few leaves or no leaves. Some desert plants have thorns instead of leaves. Thorns do not let the water go out.

During a transplant the fine roots are destroyed due to the jostling during the uprooting process. These root hairs come under a shock. The plant which has been transplanted either takes time to readjust to the new soil or dries up and dies due to the root hair loss.

Fruits respire. They give out ethylene which helps in ripening. When fruits are kept in cold storage the rate of ethylene production can be controlled and shelf life of fruits can be increased.

Nostoc fix atmospheric nitrogen and are used as inoculations for paddy crop.

All of them are employed as Biopesticides.

All of them are pollinating agents.

Carbon, Hydrogen, Nitrogen.

The blood group of the parents are AB and O; the biological child’s blood group may be A or B and since the boy is adopted and it is given in the question that “ the blood group of the three sons are A⁺, B⁺, O⁺”.

A type of trans fat occurs naturally in the milk and body fat of ruminants (such as cattle and sheep) at a level of 2–5% of total fat. Natural trans fats, which include conjugated linoleic acid (CLA) and vaccenic acid, originate in the rumen of these animals.

Human Genome Project is not at all limited to only genetic diseases. There are some 30K genes and the genome sequence would provide great help to build the tools to conquer diseases. Here we must note that all diseases have a genetic component, whether inherited (genetic) or resulting from the body’s response to environmental stresses like viruses or toxins. The successes of the HGP have even enabled researchers to pinpoint errors in genes–the smallest units of heredity– that cause or contribute to disease. Thus second statement stands correct.

Aspar tame is metabolized by the body in to two constituent amino acids and methanol. These hydrolysis products are handled by the body in the same way as aspartic acid, L-Phenylanine and methanol from other consumed foods. These components yield no calorie and add nothing new to the diet.

Phloem layer of tissue just below the bark is responsible for carrying food from leave to roots.

Pongamia Pinnata is adaptable to arid zones, and has a varied habitat distribution and able to grow in a variety of soils, it is native to humid and subtropical environment and grows naturally along coasts and river banks of India and Myanmar. It is nitrogen-fixing trees.

Crop rotation, Sand fences, terracing and wind breaks all are used for sand conservation in India. Sand fences is a simple and cheap method of inducing accretion of sands in arid and sandy areas.

Both tea and coffee is propagated by seeds and stem cutting, so the (2) option is wrong.

Mon 863 is genetically modified variety of maize, which is resistant of corn root worm.

Insectivorous plants prey insects because most of the insectivorous plants grow in those area where there is deficiet of nitrogen in nutrients so they catch insect to fulfil its need of nutrients.

Ethanol is produced in India from maize, sugarcane, starch, corn grain etc. Maize is easily available and maize is not costly for product as to economic concern.

Hepatitis-B is a poten tially life-threatening liver infection caused by the hepatitis B virus. It can cause chronic liver disease and puts people at high risk of death from cirrhoris of liver and liver cancer.
Hepatitis-B virus is transmitted between people by contact with blood or other body fluid of an contact with the blood or other body fluid.