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1. From smallest to largest: nucleotide, gene, chromosome, genome
2. The upright portion of the DNA backbone is composed of alternating sugar (deoxyribose) and phosphate portions of the nucleotides. This backbone of the DNA is very strong because it is linked by covalent bonds. The two strands of the double helix hold onto one another because of hydrogen bonding between the nitrogenous bases of complementary nucleotides.
3. The width of DNA would be inconsistent because both cytosine and thymine are the smaller pyrimidine bases, whereas guanine and adenine are larger purine bases.
4. RNA nucleotides contain the sugar ribose (DNA contains deoxyribose).
RNA is single stranded instead of double stranded, like DNA.
RNA has the nitrogenous base uracil instead of DNA’s thymine.
5. DNA sequence: ACTGACA
Complementary RNA sequence: UGACUGU
6. First, a single-ringed pyrimidine (T and C) must pair with a double-ringed purine (A and G). Second, adenine and thymine both create two hydrogen bonds, whereas guanine and cytosine both create three hydrogen bonds.
7. What is the name of the monomer of DNA? nucleotide. Which part of the monomer is the basis for the genetic language? the base (nitrogenous base).
8. DNA sequence: GGACACTT
Complementary DNA sequence: CCTGTGAA
9. A strand of DNA is wound around special proteins called histones. This mixture of DNA and protein is called chromatin.
10. b. Every correct base pairing (A-T, G-C, A-U) requires a two-ringed purine to pair with a single-ringed pyrimidine. In DNA, this makeup is especially important because it ensures that the width of the double-stranded molecule remains constant.