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.

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.

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.

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

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.

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

• Deletion

• Duplication

• Inversion

• Reciprocal translocation

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

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

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.

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.