The lac repressor prevents the lac genes in the DNA of E. coli from being expressed most of the time. The answer to your question is A. I hope this is the answer that you are looking for and it comes to your help.
Meiosis produces haploid cells rather than diploid cells because they need to make gametes (egg, and sperm cell) for reproduction.
Will occur spontaneously without the need of an activator because they have a great internal energy
The major causes of the greenhouse effect is excessive carbon dioxide gas in the atmosphere. The greenhouse effect is a process that warms the Earth's surface. When the Sun's energy reaches the Earth's atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by green house gases, such as carbon dioxide, water vapor, metahne, nitrous oxide, and ozone. The absorbed energy warms the atmosphere and the surface of the Earth.
The problems that will receive priority are the physiological needs such as air, food and water.
Maslow's hierarchy of needs is a theory in psychology which organizes people's needs according to their priorities. It is represented as a pyramid with five steps which include: physiological(at the base), safety, belongingness, esteem and self actualization.
The physiological needs at the base of the pyramid are the first priorities.