Question

assume a dna fragment is composed of 8000 base pairs. we know there are approximately 1500 thymines in the sample.

• determine the approximate amounts of:
• guanine: 6500
• cytosine: 6500
• adenine: 1500

identify the parts of a dna molecule.
w. phosphate group
x. deoxyribose sugar

1. identify the process below:
2. identify structure \2\:
3. identify structure \6\:
4. identify structure \9\:
5. identify structure \3\:

name: richie copp
final exam review packet (study guide) 2026

define:
transcription: the process of copying a segment of dna into messenger rna
translation: the process where ribosomes decode mrna to synthesize a specific amino acid chain

Explanation:

⚡ Using what you learned: central dogma of molecular biology · 🆕 New: Chargaff's rules of base pairing

Step 1: Calculate Base Pair Quantities

A double-stranded DNA fragment of \( 8000 \) base pairs (bp) contains a total of \( 16000 \) individual nucleotides:

$$ 8000 \text{ bp} \times 2 = 16000 \text{ nucleotides} $$

According to Chargaff's rules, Adenine (A) always pairs with Thymine (T), and Guanine (G) always pairs with Cytosine (C):

$$ \text{Adenine (A)} = \text{Thymine (T)} = 1500 $$

To find the remaining nucleotides for Guanine and Cytosine:

$$ \text{Total remaining} = 16000 - (\text{A} + \text{T}) = 16000 - 3000 = 13000 $$

$$ \text{Guanine (G)} = \text{Cytosine (C)} = \frac{13000}{2} = 6500 $$

Note: The values filled in the image's blanks (\text{Guanine: 6500}, \text{Cytosine: 6500}, \text{Adenine: 1500}) are correct.

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Step 2: Identify DNA Replication Components

Using the provided diagram of DNA replication:

• 5. Identify the process below: DNA Replication (indicated by the title "DIAGRAM QUIZ ON DNA REPLICATION").
• 6. Identify structure "2": DNA Polymerase III (the main enzyme synthesizing the leading strand, indicated by the blue triangle/arrow).
• 7. Identify structure "6": Okazaki fragment (the short, newly synthesized DNA fragments on the lagging strand).
• 8. Identify structure "9": DNA Ligase (the enzyme that joins the Okazaki fragments together).
• 9. Identify structure "3": Single-strand binding proteins (SSBs) (proteins stabilizing the unwound single strands of DNA).

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Answer:

Base Pair Calculations:

• Guanine: 6500
• Cytosine: 6500
• Adenine: 1500

DNA Replication Diagram Identification:

• 5. Identify the process below: DNA Replication
• 6. Identify structure "2": DNA Polymerase III
• 7. Identify structure "6": Okazaki fragment
• 8. Identify structure "9": DNA Ligase
• 9. Identify structure "3": Single-strand binding proteins (SSBs)