Which types of mutations in the lac operon stop Escherichia coli from utilizing lactose as a carbon source? a) promoter deletion b) lactose-binding site mutation c) repressor DNA-binding site mutation d) operator deletion

D.) repressor DNA-binding site mutation

Explanation:

lacl prevents the repressor polypeptide is a mutant that prevent operon from binding lactose, and thus will bind to the operator and be non-inducible.. This mutant will represses the lac operon whether lactose is present or not and the lac operon will not be expressed. It is also called“super-supperesor".

The lacI locus – One type of mutant allele of lacI (callled I-) prevents the production of a repressor polypeptide or produces a polypeptide that will not allow to bind to the operator sequence.

This is also a constitutive expresser of the lac operon because absence of repressor binding permits transcription.

✿   this landform has a high elevation and a high relief

✿   this landform is a mountain

1. a host loses nutrients to a parasite

2. a parasite only benefits when the host is alive (cause if the host dies the parasite dies with it )

3. producers to consumers

4. the tapeworm is a parasite

5. they convert energy from the sun (photosynthesis)

6. sunflower-robin (i think im 80% sure)

7. producer

8. consumer

9. prey

10. fresh water snails ( cause the green algea is the producer and the snails are the primary consumers and the small fish consumer so is the big fish)