Chromosome Maps

Q. Construct a chromosome map with the given crossover frequency of each of the genes.

Gene	Frequency of crossover
A-C	30%
B-C	45%
B-D	40%
A-D	25%

1. ABCD
2. BADC
3. CADB
4. DABC

Q. 1 centimorgan signifies

1. 10% crossing over.
2. 50% crossing over.
3. 100% crossing over.
4. 1% crossing over.

Q. What map unit (centimorgan) is adopted in the construction of genetic maps?

1. A unit of distance between genes on chromosomes, representing 50% cross over
2. A unit of distance between two expressed genes, representing 10% cross over
3. A unit of distance between two expressed genes, representing 100% cross over
4. A unit of distance between two expressed genes, representing 1% cross over

Q.

The map distances between genes A and B is 3 units, between B anc C is 10 units and between C and A is 7 units. The order of the genes in a linkage map constructed on the above data would perhaps be:

1. A, B, C

2. A, C, B

3. B, C, A

4. B, A, C

Q.

Map distance of genes is calculated by ___.

1. Number of mutant genes

2. Crossover percentage

3. Recombination frequency of each gene locus

4. Non crossover percentage

Q. Distance between two linked genes is measured in map units which depicts the of crossing over.

1. frequency
2. strength
3. intensity
4. alleles

Q. In somatic cells, chromosomes are found in while in gametic cells, chromosomes are found in .

1. pairs
2. single sets
3. triplet
4. random numbers

Q.

Distance between two linked genes is measured in map units that depict:

1. Ratio of crossing over between them

2. Crossover value

3. Number of genes between them

4. Both b & c

Q.

Distance between two linked genes is measured in map units that depict:

1. Ratio of crossing over between them

2. Crossover value

3. Number of genes between them

4. Both b & c