Question

name diego ayala dna structure and replication practice date 19 - 14 - 25 class pd 2nd
label the diagram. use these choices: nucleotide, deoxyribose, phosphate group, nitrogen base,
hydrogen bonds, base pairs

1. sugar

2.
3.
4.
5.
6.
complete the chart over base pair rules
complete the sentence:
according to chargaffs rules, the purine base guanine will pair with the pyrimidine base
________, and the purine base adenine will pair with the pyrimidine base
______. these nitrogen bases are held together by weak ______ bonds that
are easily broken during replication. the nitrogenous bases make up the ________ of the double
helix.

Explanation:

• Labeling the DNA Diagram:
• A DNA nucleotide is composed of deoxyribose (a 5 - carbon sugar), a phosphate group, and a nitrogen base. The "backbone" of DNA is made up of alternating deoxyribose and phosphate groups. The nitrogen bases (adenine, thymine, cytosine, guanine) pair up in the middle of the double - helix via hydrogen bonds.
• Base pairs (adenine - thymine and cytosine - guanine) are the pairs of nitrogen bases that form the "rungs" of the DNA ladder.
• Base Pair Rules Chart:
• According to Chargaff's rules (and the complementary base - pairing rules in DNA), adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G).
• Completing the Sentence:
• As mentioned above, guanine (a purine) pairs with cytosine (a pyrimidine), and adenine (a purine) pairs with thymine (a pyrimidine). The bonds between nitrogen bases are hydrogen bonds. The nitrogenous bases form the base pairs (the "rungs" of the DNA double - helix ladder).

Answer:

• Labeling the DNA Diagram (assuming a standard DNA diagram structure):
• 1. deoxyribose
• 2. phosphate group
• 3. nucleotide
• 4. nitrogen base
• 5. hydrogen bonds
• 6. base pairs
• Base Pair Rules Chart:
• First row: Thymine (T) pairs with Adenine (A)
• Second row: Cytosine (C) pairs with Guanine (G)
• Third row: Adenine (A) pairs with Thymine (T)
• Fourth row: Guanine (G) pairs with Cytosine (C)
• Completing the Sentence:
• According to Chargaff’s Rules, the purine base guanine will pair with the pyrimidine base cytosine, and the purine base adenine will pair with the pyrimidine base thymine. These nitrogen bases are held together by weak hydrogen bonds that are easily broken during replication. The nitrogenous bases make up the base pairs of the double helix.