Answer:
With respect to the composition of DNA, in an analysis it can be found that the proportions of nucleotides are A + C = G + T (option a).
Explanation:
The proportion of nucleotides in a DNA molecule can be established according to the sequence of these nucleotides on both complementary strands, since the purinic bases of one strand are complemented by the pyrimidinic bases of another:
- <em>Adenine is complemented with Thymine A=T</em>
- <em>Guanine is complemented with Cytosine G=C</em>
From this we can deduce that in a DNA molecule with two chains there will be the same amount of adenine and thymine, as well as the same number of guanine with respect to cytosine, so:
<em> A + C = G + T</em>
An example of this would be a known DNA molecule (hypothetical), with 5 molecules of Adenine and 7 molecules of Guanine. In this case there are 5 Thymines, complementary with Adenine, and 7 Cytosines like Guanine:
<em> A + C = G + T</em>
<em> 5 + 7 = 7 + 5</em>
Answer:
interleukin-2 (IL-2) is an interleukin, a type of cytokine signaling molecule in the immune system. It is a 15.5–16 kDa protein[5] that regulates the activities of white blood cells (leukocytes, often lymphocytes) that are responsible for immunity. IL-2 is part of the body's natural response to microbial infection, and in discriminating between foreign ("non-self") and "self". IL-2 mediates its effects by binding to IL-2 receptors, which are expressed by lymphocytes. The major sources of IL-2 are activated CD4+ T cells and activated CD8+ T cells
Explanation:
<h2>Genetic diversity </h2>
Explanation:
If the environment changes, the species runs the risk of not having the genetic diversity to be adaptable to that change and could go extinct
- Genetic diversity is the diversity or genetic variability within species
- The huge variety of different gene sets defines an individual or a whole population's ability to tolerate stress from any given environmental factor
- While some individuals might be able to tolerate an increased load of pollutants in their environment, others carrying different genes might suffer from infertility or even die under the exact same environmental conditions;the former will continue to live in the environment the latter will either have to leave it or die
- Any change in the environment - natural or human induced causes a selection of events that only the fittest survive
- In case of elephant seals,overhunting reduces the sum of genes available,thus leaving behind a population that is less capable of tolerating any further natural or human disturbances in environment
- The loss of genetic diversity within a species can result in the loss of useful and desirable traits
<span>Testosterone achieves his effect by binding to his androgen receptor (nuclear). Because testosterone is steroid hormone (derived from cholesterol), it has a possibility to free diffuse through the cell membrane. When testosterone binds, the receptor undergoes a structural change which allows it to move into the cell nucleus and dimerize. Receptor dimer than binds directly to the specific sequence of the DNA called hormone response element (HRE) which results in regulation of gene expression.</span>
