31.

A lake with an inflow of domestic sewage rich in organic waste may result in

• drying of the lake very soon due to algal bloom

• an increased production of fish due to lot of nutrients

• death of fish due to lack of oxygen

• increased population of aquatic food web organisms.

Minamata disease was caused due to the consumption of

• sea food containing lot of cadmium

• fish contaminated with mercury

• oysters with lot of pesticide

• sea food contaminated with selenium.

An artificial pacemaker is implanted subcutaneously and connected to the heart in patients

• having 90% blockage of the three main coronary arteries

• having a very high blood pressure

• with irregularity in the heart rhythm

• suffering from arteriosclerosis.

An example of gene therapy is

• production of injectable hepatitis B vaccine

• production of vaccines in food crops like potatoes which can be eaten 

• introduction of gene for adenosine deaminase in persons suffering from Severe Combined Immuno-deficiency (SCID)

• production of test tube babies by artificial insemination and implantation of fertilized eggs

The pollen tube usually enters the embryo sac

• through one of the synergids

• by directly penetrating the egg

• between one synergid and central cell

• by knocking off the antipodal cells.

What is the first step in the Southern Blot technique

• Denaturation of DNA on the gel for hybridization with specific probe

• Production of a group of genetically identical cells

• Digestion of DNA by restriction enzyme

• Isolation of DNA from a nucleated cell such as the one from the scene of crime

Women who consumed the drug thalidomide for relief from vomiting during early months of pregnancy gave birth to children with

• no spleen

• hare-lip

• extra fingers and toes

• underdeveloped limbs.

Given below is a pedigree chart of a family with five children. It shows the inheritance of attached ear-lobes as opposed to the free ones. The squares represent the male individuals and circles the female individuals. Which one of the following conclusions drawn is correct

• The parents are homozygous recessive.

• The trait is Y-linked.

• The parents are homozygous dominant.

• The parents are heterozygous.

Given below is a representation of a kind of chromosomal mutation. What is the kind of mutation represented

• Deletion

• Duplication

• Inversion

• Reciprocal translocation

Which one of the following pairs is correctly matched with regard to the codon and the amino acid coded by it

• UUA - valine

• AUG - cysteine

• AAA - lysine

• CCC - alanine