1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
padilas [110]
3 years ago
7

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
Biology
1 answer:
Sladkaya [172]3 years ago
7 0

Answer:

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.

You might be interested in
What is the climate like in the Yellowstone forest?​
Dominik [7]

Answer:

maybe it helps

Explanation:

Daytime temperatures are often around 70°F (25°C) and occasionally 80°F (30°C) at lower elevations. Nights are usually cool and temperatures may drop below freezing at higher elevations.

4 0
3 years ago
What is the difference between osmosis and diffusion​
PilotLPTM [1.2K]

Answer:

Osmosis is the movement of molecules from a region of lower concentration to a region of higher concentration through a semi-permeable membrane

WHILST

Diffusion is the movement of molecules from a region of higher concentration to a region of lower concentration until the molecules are evenly distributed

5 0
2 years ago
Read 2 more answers
The role that p53 protein plays in suppressing inappropriate progression through the cell cycle depends on all of the following
irinina [24]

Answer:

a. p53 activates transcription of WAF1.

Explanation:

<u>WAF1 transcription occurs independent of p53 during oxidative stress so p53 does not play any role in cell cycle arrest in the signaling pathway which involves WAF1 . </u>

In rest of the mentioned options, p53 plays a role directly or indirectly. During double stranded lesion in DNA in G1 phase, a sensor protein known as ATM binds the DNA lesion site. ATM is a serine/threonine kinase which phosphorylates another kinase known as chk2. After phosphorylation,<u> chk2 stabilizes transcription factor p53.</u> p53 further acts as a transcription factor for the synthesis of a protein known as p21 which inhibits G1 phase specific CDK and ultimately cell is arrested in G1 phase. The cell remains in arrested state until the DNA lesion is fully repaired. <u>Hence, p53 indirectly blocks G1 to S transition with the help of p21. </u>

As such <u>WAF1 transcription factor involving pathway</u><u> </u><u>also requires p21 protein for causing cell cycle arrest but in this pathway p21 is not synthesized with the help of p53. </u>

5 0
3 years ago
Mmune cells can squeeze out of the capillaries to go to a site of injury. this is called:
yuradex [85]
Granulocyte ( Polymorph.).

Commonest phagocytic white cells; can squeeze out of blood capillaries into tissues, have a short lifespan; made in the bone marrow.




Hope this helps!!!!!!
5 0
3 years ago
Sperm whales, a(n) species, maintain their populations close to carrying capacity.
soldier1979 [14.2K]
The answer is K-selected.

<span>The population size of K-selected species is fairly constant in time, unlike the population size of r-selected species. r-selected species are usually bellow carrying capacity and the population size is density independent. On the contrary, K-selected species are usually near or at carrying capacity and the population size is density dependent. It can be concluded that sperm whales have K-selected populations, since they </span><span>maintain their populations close to carrying capacity.</span>

4 0
3 years ago
Read 2 more answers
Other questions:
  • State one reason why the large ground finch and the woodpecker finch can live successfully
    13·1 answer
  • he __________ system works with the nervous system to protect important organs such as the brain and spinal cord. A) skeletal B)
    6·2 answers
  • If the apical meristem of a mature plant is removed, the plant will most likely
    7·1 answer
  • Due to the coronavirus pandemic, more scientists have taken to testing the effectiveness of different masks. Recently, conflicti
    8·1 answer
  • Which of the following characteristics of living things could be applied to an automatic door at a supermarket?
    8·1 answer
  • The simplest sugars are generally called _____.
    11·2 answers
  • 02:46:15
    12·2 answers
  • Does anyone know something that I could do to help myself focus bcs I have ADD and I'm failing?
    12·2 answers
  • What happens when the pollen gets past the nasal mucus osmosis Jones
    11·1 answer
  • What can stimulate cell regulators to increase cell reproduction?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!