Answer:
vaccination
Explanation:
The vaccination has been one of the most revolutionary inventions in the medical field. This invention helped protect people from numerous diseases, some being totally neutralized, while some having only minor effects on the human body. The vaccination basically is a way of enhancing the immune system of the body by injecting in it a weakened form of the pathogen. In this way, the weakened form of the pathogen is not capable to harm the body, and the body is not fighting against it, but instead the pathogen becomes part of the body and its defense mechanism, so when the pathogen strikes, the body has a counter attack and defeats it.
It is called speciation.
So it'll be D. Speciation
Hope this helped :)
<h3>In general,the more massive a star is,the shorter it's life span on the main sequence.After the hydrogen fuel at the core has been consumed,the star evolves away from the main sequence on the HR diagram,into a supergiant,red giant,or directly to a white dwarf.</h3>
<h2>--SirGerick--</h2>
Telomerase activity is controlled during development and is extremely low in somatic (body) cells, virtually undetectable. These somatic cells age because they do not frequently use telomerase.
- Telomeres are repetitive sections at the very ends of chromosomes that are present in a variety of eukaryotic species, including humans and unicellular protists.
- Each round of DNA replication wears down a little portion of the telomeres, which serve as caps to safeguard the interior chromosomal regions.
- Most somatic (body) cells do not typically have telomerase activity, but certain adult stem cells and germ cells—the cells that produce sperm and eggs—have.
- Adult germ cells, tumor cells, and fetal tissues all contain telomerase. Telomerase activity is controlled during development and is extremely low in somatic (body) cells, virtually undetectable. These somatic cells age because they do not frequently use telomerase.
learn more about telomerase here: brainly.com/question/14213408
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