Answer:
The correct answer is b. He determined that DNA contains four nitrogenous bases.
Explanation:
Levene was an American biochemist who studied the structure of DNA in the early 1900s and in 1920 he found that DNA consists of four nitrogenous bases that are Adenine, Guanine, Thymine, Cytosine.
He also found deoxyribose sugar and phosphate group and said that nucleotide is the basic unit of DNA which contains a ribose sugar with attached nitrogenous base and phosphate group.
He also concludes that an equal amount of adenine, guanine, thymine, and cytosine makes the DNA which is now known as tetranucleotide hypothesis. So the correct answer is b. He determined that DNA contains four nitrogenous bases.
<span>Other mutagens act by chemically modifying the bases of DNA. For example, nitrous acid (HNO2) reacts with bases that contain amino groups. Adenine is oxidatively deaminated to hypoxanthine, cytosine to uracil, and guanine to xanthine. ... Uracil pairs with adenine rather than with guanine.</span><span>
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"It is extremely subjective" is the one statement among the following choices given in the question that is false regarding <span>cladistic analysis. The correct option among all the options that are given in the question is the fourth option or option "d". I hope that this is the answer that has actually come to your help.</span>
It will run out or have a very little amount
