Question

1. based on the diagram to the left, identify the structures labeled 1-5. terms: cytosine, thymine, sugar, phosphate, nucleotide. 4 pts1. 2. 3. 4. 5. 14. answer the following questions using your understanding of dna and chargaff base pairing rule. 2 ptsa. in an organism with only 1 chromosome that has 22% thymine. what are the percentages of adenine, cytosine, and guanine?adenine thymine cytosine guanine a. in an organism with only 1 chromosome that has 150 base pairs, 80 nucleotides have the nitrogen base guanine. how many nucleotides have adenine, cytosine, and thymine?adenine thymine cytosine guanine 15. use the dna sequence below to write the complementary dna, mrna, and amino acid sequence. 3 ptsdnaatgcagtcaattttgatacgtcagtaaaaactmrnatrnaamino acidsextra credit: identify the trna anticodon sequence.

Explanation:

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Question 13

Step1: Identify structure 1

Structure 1 is the phosphate group, the circular component at the end of the nucleotide backbone.

Step2: Identify structure 2

Structure 2 is the 5-carbon sugar (deoxyribose) linking phosphate and base.

Step3: Identify structure 3

Structure 3 pairs with Adenine (A); in DNA, A pairs with Thymine.

Step4: Identify structure 4

Structure 4 pairs with Guanine (G); in DNA, G pairs with Cytosine.

Step5: Identify structure 5

Structure 5 is a full unit of phosphate + sugar + base, a nucleotide.

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Question 14 (Left, Chargaff's Rules)

Step1: Apply A-T pairing rule

In DNA, %Adenine = %Thymine. Given %Thymine=22%, so %Adenine = 22%.

Step2: Calculate total G+C percentage

Total bases = 100%. Subtract A+T: $100\% - (22\% + 22\%) = 56\%$

Step3: Apply G-C pairing rule

%Guanine = %Cytosine. Divide G+C total by 2: $\frac{56\%}{2} = 28\%$, so %Guanine=%Cytosine=28%.

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Question 14 (Right, Chargaff's Rules)

Step1: Calculate total nucleotides

150 base pairs = $150 \times 2 = 300$ total nucleotides.

Step2: Apply G-C pairing rule

%Guanine = %Cytosine, so Cytosine count = 80.

Step3: Calculate remaining nucleotides

Subtract G+C from total: $300 - (80 + 80) = 140$

Step4: Apply A-T pairing rule

Divide remaining nucleotides by 2: $\frac{140}{2} = 70$, so Adenine=70, Thymine=70.

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Question 15

Step1: Write complementary DNA

Pair DNA template (top strand: A T G C A G T C A T T T T T G A) with complementary bases: A-T, T-A, G-C, C-G.

Step2: Transcribe to mRNA

Replace T with U in the complementary DNA: A→U, T→A, G→C, C→G.

Step3: Translate mRNA to amino acids

Group mRNA into codons: AUG (Methionine), CAG (Glutamine), UCA (Serine), UUU (Phenylalanine), UUG (Leucine)

Step4: Write tRNA anticodons

Pair each mRNA codon with complementary bases: AUG→UAC, CAG→GUC, UCA→AGU, UUU→AAA, UUG→AAC

Answer:

Question 13:

1. Phosphate
2. Sugar
3. Thymine
4. Cytosine
5. Nucleotide

Question 14 (Left):

Adenine: 22%
Thymine: 22%
Cytosine: 28%
Guanine: 28%

Question 14 (Right):

Adenine: 70
Thymine: 70
Cytosine: 80
Guanine: 80

Question 15:

Complementary DNA: T A C G T C A G T A A A A A C T
mRNA: A U G C A G U C A U U U U U G A
Amino Acids: Methionine, Glutamine, Serine, Phenylalanine, Leucine
tRNA Anticodon Sequence: U A C, G U C, A G U, A A A, A A C