Identify which of the following lac operon haploid genot...

Question

Identify which of the following lac operon haploid genotypes transcribe operon genes inducibly and which transcribe genes constitutively. Indicate whether the strain is lac⁺ (able to grow on lactose-only medium) or lac⁻ (cannot grow on lactose medium).

I⁻ P⁺ O⁺ Z⁺ Y⁺

Accepted Answer

Hi, everybody. Here's our next question provided the following genotypes which of them can grow on a lactose only medium. And we have choice. A lack I minus lack Z plus, lack Y plus la A plus choice B lack I plus la Z minus, like Y plus like a plus choice. C lack I plus la Z plus, lack Y minus, lack a plus or choice. D all options are correct. So we need to think about which of the following genotypes, which mutation still allows the cells to grow on a lactose only medium. So still retain the ability to metabolize lactose. Remembering that we have that choice d possibility that all the options are correct. Well, since we need them to be able to metabolize lactose, we need these structural genes to be intact black Z which codes for the enzyme beta galacto itis because that breaks down the lactose into galactose and glucose. Without that, the cell is unable to metabolize that disaccharide lactose. And then we need a lack Y gene to be intact as that codes for the enzyme permeate, which allows the transport and uptake of lactose into the cells. So, if the lactose can't get into the cells. The cells can't use lactose as their energy source. So we need the lac Z and lack Y genes to be intact. When we look at choice A, we see that indeed, we're lack C plus and lack Y plus. The only one that is mutated is lack I and that's the gene for the lac repressor protein. So with that mutated, it means that these structural genes will be expressed constituently regardless of the cell conditions. So it doesn't matter if there's lactose, no lactose, it will be expressed in these genes. So these will be able to grow on lactose only medium because they have those necessary genes to produce the proteins that are needed. Choice B we have lack Z minus. If we're lacking beta beta galactosidase, which is coded for by lax C, they cannot use lactose as their energy source. So will not grow on lactose only medium. So choice B cannot be correct. Therefore, we can also eliminate choice D since we have an incorrect answer. And then finally, in choice C, we have the lack Y gene that is not working. And therefore the cell can't produce permeates. Lactose can't be taken up into the cells and they will not grow on a lactose only medium. So that's why choice C is not correct. So again, provided the following genotypes which can grow on lactose medium. Choice, a lack I minus lack Z plus lack Y plus lack a plus. See you in the next video.

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Identify which of the following lac operon haploid genotypes transcribe operon genes inducibly and which transcribe genes constitutively. Indicate whether the strain is lac⁺ (able to grow on lactose-only medium) or lac⁻ (cannot grow on lactose medium).

I⁻ P⁺ O⁺ Z⁺ Y⁺

My Courses

Chemistry

Biology

Math

Physics

Business

Social Sciences

Programming

Product & Marketing

Identify which of the following lac operon haploid genotypes transcribe operon genes inducibly and which transcribe genes constitutively. Indicate whether the strain is lac⁺ (able to grow on lactose-only medium) or lac⁻ (cannot grow on lactose medium).I⁻ P⁺ O⁺ Z⁺ Y⁺

Identify which of the following lac operon haploid genotypes transcribe operon genes inducibly and which transcribe genes constitutively. Indicate whether the strain is lac⁺ (able to grow on lactose-only medium) or lac⁻ (cannot grow on lactose medium).

I⁻ P⁺ O⁺ Z⁺ Y⁺