The first description of the DNA (deoxyribonucleic acid)chain was done by Watson and Crick in 1953, the nucleotides that constitute the DNA are four: cytosine (C), guanine (G), timine (T) and adenine (A). When doing a model is essential to remember that cytosine ONLY joins guanine and timine only link adenine, this is due to the size and chemical properties of each molecule. Later, another related and similar and molecule was discovered, the ribonucleic acid or RNA, which also is constructed by nucleotides.
In both cases, the nucleotides are compound of 3 main components: a nitrogen base, a pentose and a phosphate. When the molecule lacks the phosphate group, is called nucleoside. Depending on the chain ( DNA or RNA) the nitrogen base derives from purine (adenine and guanine) or pyrimidine (cytosine or timine) just in the RNA instead of timine is uracil (U)
The union is established between adjacent molecules through the phosphate, while among each other through the nitrogen base-remember C=G and T or U=A. The core of each molecule is the pentose. Therefore the best representation of the molecule is attached
References
Watson, J. D., & Crick, F. H. (1953, January). The structure of DNA. In Cold Spring Harbor symposia on quantitative biology (Vol. 18, pp. 123-131). Cold Spring Harbor Laboratory Press.
Answer:
D-It created a less rigid social class system.
Explanation:
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When Joseph sees a frail man limping around the corner he owns, he will likely help if the costs of helping are small and Joseph will feel better about himself helping.
Helping someone in need corresponds to a form of empathy and altruism, which is based on the moral emotions we feel when we see a person in a situation that we have the ability to help.
According to the theory of social exchange, altruism only exists if the benefits to the helper outweigh the cost, so supported by this theory, the letter b is correct, and Joseph will help the man if the costs of helping are small.
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Answer:
2) "Multiple drugs are necessary because the bacteria are likely to develop resistance to just one drug."
Explanation:
Tuberculosis is caused by multiple bacteria, and these bacteria can easily develop resistance if only one antibiotic is used. Current medical research recommends the usage of several antibotics in the treatment of Tuberculosis for these same reasons.
The voting rights Act of 1965 refer to the Act that was signed by President Lyndon Johnson to give the African american their rights to vote
This act was really long overdue, considering that the African American was really discriminated. With this act, all the legal barriers that prevented African American for exercising their right to vote were eliminated
