<span>DNA is made of chemical building blocks called nucleotides. These building blocks are made of three parts: a phosphate group, a sugar group and one of four types of nitrogen bases. To form a strand of DNA, nucleotides are linked into chains, with the phosphate and sugar groups alternating.</span>
Answer:
Yes, there is no convincing scientific evidence that thimerosal causes harm by the low doses of thimerosal in vaccines, except for minor reactions like redness and swelling at the injection site
Explanation:
Thimerosal has been used safely as a vaccine additive, added to some vaccines to prevent germs like bacteria and fungi from growing in them dated since early 1930s. Though, Thimerosal contains mercury but the type of mercury doesn’t stays in the body, and is unlikely to make human fall sick.
Most people doesn't have any allergic reaction to it except for redness and swelling at the injection site as early mentioned and this is considered irrelevant when compared to effect of vaccine when contaminated by germ which could cause serious illness or death.
Answer:
Changes that cannot be reversed are called irreversible changes
Example: if you cook an egg or if something goes bad. these changes can not be reversed.
In the greenhouse effect, far infrared radiation is emitted from the Earth's surface and absorbed and reemitted by some gases in the atmosphere.
These gases have increased in concentration over the past century.
<h3>What is the greenhouse effect?</h3>
The greenhouse effect refers to the effect that occurs due to certain gases present in the atmosphere which serves as blanket by preventing escape of heat from the earth.
Greenhouse gases include most especially carbon dioxide.
In the greenhouse effect, far infrared radiation is emitted from the Earth's surface and absorbed and reemitted by some gases in the atmosphere.
These gases have increased in concentration over the past century.
Learn more about greenhouse effect at: brainly.com/question/17023405
The answer is <span>d. homologous structures.
Homologous structures are </span><span>similar structures shared by different species. For example, the anatomy of joints in bones of birds and dinosaurs, support the idea that these two groups have a common ancestor. But since these two groups are different enough to be separated into different classes, it can be concluded that they evolved from the common ancestor.</span>