Select the correct statement from the ones given below with respect to dihybrid cross:

1.	Tightly linked genes on the same chromosome show higher recombinations
2.	Genes far apart, on the same chromosome, show very few recombinations
3.	Genes loosely linked, on the same chromosome, show similar recombinations as the tightly linked ones
4.	Tightly linked genes on the same chromosome show very few recombinations

Which one of the following symbols and its representation, used in the human pedigree analysis is correct?

1.	= Mating between relatives
2.	= Unaffected male
3.	= Unaffected female
4.	= male affected

Sickle cell anaemia is:

Point mutation involves:

1. insertion

2. change in single base pair

3. duplication 

4. deletion

Study the pedigree chart given below:

What does it show?

Select the incorrect statement from the following:

A human male produces sperms with the genotypes AB, Ab, aB and ab pertaining to two diallelic characters in equal proportions. What is the corresponding genotype of this person?

1. AaBb

2. AaBB

3. AABb

4. AABB

In hexaploid wheat, the haploid (n) ar basic (x) numbers of chromosomes are:

1. n=7 and x=21

2. n=21 and x=21

3. n=21 and x=14

4. n=21 and x=7

Inheritance of skin colour in humans is an example of:

1. chromosomal aberration

2. point mutation

3. polygenic inheritance

4. codominance