Answer:
The correct option is B (natural killer cells).
Explanation:
Natural killer cells: They are defined as the type of cytotoxic lymphocyte which are critical to the innate immune system. The NK cells play an important role in to provide rapid response to tumor formation, virus infected cells, and acting after three days of infection.
While cancer cells die, they release some antigens, than these antigens are recognized by the immune system, and later they are presented on the immune cells which are known as antigen presenting cells. So, if these cells are absent than they increase the chances of developing malignant tumors.
Water would move from outside to the inside of the cell through the semi permeable cell membrane and cause the cell to swell.
<span>The RNA world is the hypothesized format of chemical life that existed prior to our current DNA and RNA world. In the RNA world, RNA molecules formed in the primordial soup and began to evolve by self-replication and mutation. This led to increased complexity, natural selection of "better" RNA and diversification of RNA based life.</span>
Answer:
The correct option is <em>B) ultraviolet region, especially below a wavelength of 320 nm.</em>
Explanation:
Ultraviolet light carries an enormous amount of energy in it. It is invisible to the human eye. When UV light with enormous energy and wavelength lesser than 320nm, hits the DNA, it causes changes in the structure of the DNA. Mostly, it affects the thymine nitrogenous base regions and forms pyrimidine dimers. The structure of the DNA changes on all the sites where dimers form and hence, they cannot be properly transcribed.
