The answer is A I took the k12 test
The gradual abundance of oxygen (by product of photosynthesis) made it possible for aerobic organisms to grow more and evolve.
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Answer:
1. Double helix is the description of the structure of a DNA molecule. A DNA molecule consists of two strands that wind around each other like a twisted ladder. Each strand has a backbone made of alternating groups of sugar (deoxyribose) and phosphate groups.
2. The DNA double helix. The two sides are the sugar-phosphate backbones, composed of alternating phosphate groups and deoxyribose sugars. The nitrogenous bases face the center of the double helix.
3. A nucleotide is an organic molecule that is the building block of DNA and RNA. ... A nucleotide is made up of three parts: a phosphate group, a 5-carbon sugar, and a nitrogenous base. The four nitrogenous bases in DNA are adenine, cytosine, guanine, and thymine.
4. A nucleotide is made up of three parts: a phosphate group, a 5-carbon sugar, and a nitrogenous base. The four nitrogenous bases in DNA are adenine, cytosine, guanine, and thymine.
5. In genetics, the term junk DNA refers to regions of DNA that are non-coding. Some of this noncoding DNA is used to produce noncoding RNA components such as transfer RNA, regulatory RNA and ribosomal RNA
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