Question

A cistron is defined by no complementation in the (cis or trans) configuration.

Eight mutant bacteriophage strains cannot lyse a certain type of bacteria that can be lysed by wild-type bacteriophages. The mutant strains were allowed to infect the bacteria in a complementation test. A '+ indicates that lysis occurred with coinfection. A - indicates that lysis did not occur. 4i A cistron is defined by no complementation in the How many genes are controlling lysis in this bacteriophage? (Use a number not a word in the space) Which of the following strains below are defective in the same gene as strain W? Answer yes if the strain is defective or no if it is not. +configuration Strain Defective W N/A

Please answer all with explaination, thank you!

Answer 1

A cistron is defined by no complementation in the trans configuration. In this, we are talking about the DNA sequence or the cistron that consists of the gene. The complementation is defined by the gene present.

In this we see that there are around 4 genes which are probably controlling the lysis of the bacteriophage. In the mutation version, on combining there are certain types of mutant strains that were allowed to interact for lysis. It was found that in presence of M, T,M Q as one of them, lysis occurred.

G	Yes – It is defective as it is not able to lysis and it gives us a negative for the complementation test.
K	Not-defective
W	Yes – Defective as when it is present alone, it is not able to undergo lysis. It was observed it can undergo lysis only when combined with K.
T	Not-defective
M	Not-defective
A	Defective – It is not able to undergo lysis of the bacteriophage.
Q	Not-defective
C	Defective - It is not able to lyse the bacteriophage.