Several bacterial strain lac operon genotypes

Solution-Common type of fracture in the elderly
April 21, 2020
The chromosomes of many of cells are plainly visible
April 21, 2020

Several bacterial strain lac operon genotypes

The following table shows several bacterial strain lac operon genotypes (some are partial diploids).

a) Fill in the blanks in the “lactose absent” and “lactose present” columns in this table. (+) means significant levels of active ß-galactosidase enzyme can be detected. (–) means no significant levels of active ß-galactosidase enzyme. The first line is filled in for reference.
Strain genotype
Lactose absent
Lactose present

1. lacI+ lacP+ lacO+ lacZ+ lacY+
2. lacI+ lacP+ lacOc lacZ+ lacY+
3. lacI+ lacP+ lacOc lacZ– lacY+
4. lacIs lacP+ lacOc lacZ+ lacY+
5. lacI– lacP+ lacO+ lacZ+ lacY+ / lacI+
6. lacIs lacP+ lacO+ lacZ+ lacY+/ lac I+

b) If lactose is absent and glucose is present in the culture medium of strain 4, will significant levels of active ß-galactosidase enzyme be detected? Explain… in brief, just because there is lots of room left, you don’t need to fill it.