Explanation:
Melanin is the pigment which absorbs UV light and it is present in skin and gives black colour to it.As we can see africans usually have black skin as they have to face direct uv light.
Answer:
A. Glucose:
As lactose is absent will follow the glucose metabolism, so the lac repressor will hold tightly with the operator which leads to the prevention of transcription as RNA polymerase can not bind to promoter so no lactose metabolism.
B. lactose:
In the case or wild mutant lactose metabolism will occur as lactose is present, allolactose binds to the lac repressor thus the operator and promoter are free so transcription starts. The same result will be in all test except in the case of a mutant repressor.
C. glucose and lactose:
In this case, diauxic growth will occur. This growth takes place when two sugars are present in the media. The preferred sugar will be consumed first That is glucose. Then a lag phase will come which will be followed by the second sugar metabolism that is lactose. the given two cases :
Lactose will be metabolized first, as operator site mutation prevents repressor protein binding and thus will lead to the constitutive synthesis of lac operon in test B.
The same thing will happen, as in this case also, constitutive synthesis of lac operon will happen in test C.
Cultures grown in the presence of both glucose and lactose are metabolizing lactose. In the test (b) and (c) will be responsible due to constitutive synthesis of lac operon will happen.
Answer:
They are both celestial bodies orbiting our Sun, and they both can have unusual orbits, sometimes straying close to Earth or the other planets
Answer:
The HIV genome is originally a RNA based genome.
Explanation:
Human immunodeficiency viruses are the one which infects human over time. The virus infects human body cells and progresses towards immune system failure which creates life threat for a patient. The disease is incurable till date but the effects can be slowed down by the medication and treatments. The disease in contagious and spreads by transfer of infected blood.
<span>The experimenters should make sure they are using proper clothing and shoes while properly coverings the exposed skin areas. Apart from that they should take proper measures to protect their eyes with proper safety goggles. If using contact lenses rather use eye glasses instead of that.</span>
