Cytogenetics Practice Test 5

1. If two genes are unlinked the recombination frequency will be?

75%

50%

25%

100%

2. Linkage results in __________

Formation of more parental phenotype

Formation of more Dominant phenotype

Formation of more recombinant phenotype

Formation of more Wild phenotype

3. How many rounds of replication in BrdU will be needed to visualize Harlequin chromosome?

Four

Three

Two

Single

4. In which of the following cases will the viral progeny generated retain their infection ability?

A generalized trasducing phage affects a normal cell

A specialized transducing phage will attack a normal cell

A specialized transducing phage affects a cell infected by same virus

A generalized transducing phage will affect a cell with a different viral infection

5. If an organism has 8 chromosomes in diploid condition, what will be the number of chromosomes after telophase of meiosis 1?

6. In an experiment you have a U-Tube with two strains of bacteria in two arms. In one arm the bacteria are Gal+ and His-, in other the strain is Gal- and His+. If the two arms are joined by a membrane that doesn’t allow bacterial cells to pass to opposite site what will you observe when you plate each arm bacterial strain on minimal media?

Some colonies seen in left arm

Some colonies seen in right arm

None will grow

Some colonies seen in both arms

7. You study the gene incorporation in recipient using HFR and get the following sequences-
P-W-A-K, W-L-I-K, A-K-I-L, W-P-R-T-W-L. What is the order of the gene?

W-A-K-I-L-P-R-T-W

W-P-R-T-W-L-A-K-I

A-K-I-L-W-T-R-P-W

P-W-A-K-W-T-R-L-I

8. Integration of the phage into bacterial genome requires__________________

XIS and FIS

Integrase and IHF

XIS and IHF

Integrase and XIS

9. A HFR bacteria mates with an F- plasmid containing bacteria. What will be the type of bacteria after conjugation is complete?

F+

F’

F-

HFR

10. In and interrupted mating experiment, it is seem that the after 10 mins Azi^R gene in recipient, after 20 minuites there is appearance of ton^R and after 15 mins the recipient is lac⁺ , but the recipient is almost never his⁺. Where in the genome is the ori of transfer?

Between Azi^R and Ton^R genes

Between His⁺ and Azi^R

Between Lac⁺ and His⁺

Between Ton^R and Lac⁺