Nucleotides and Nucleic Acids | OCR A-Level Biology A (H420)
Nucleotides and Nucleic Acids
- 58 questions
- 5 subtopics
- Module 2: Foundations in biology
- Component 01, Component 02 and Component 03
Nucleotides and nucleic acids is the third section of Module 2.
It covers what a nucleotide is made of, how nucleotides join into DNA and RNA, the structure of the double helix, how DNA copies itself semi-conservatively, and how a gene is read out into a polypeptide.
Sample questions from Nucleotides and Nucleic Acids
Answer each one closed book first, then open the answer.
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Nucleotide structure and the bases
Which pentose sugar is found in DNA nucleotides?
Show the answer
Deoxyribose. -
Nucleotide structure and the bases
Is guanine a purine or a pyrimidine?
Show the answer
Guanine is a purine. -
Polynucleotides, ADP and ATP
What type of reaction breaks down polynucleotides into individual nucleotides?
Show the answer
A hydrolysis reaction. -
Polynucleotides, ADP and ATP
How many phosphate groups does ADP contain?
Show the answer
Two phosphate groups. -
The structure of DNA
In DNA, which base pairs with guanine?
Show the answer
Cytosine. -
The structure of DNA
What three components make up a DNA nucleotide?
Show the answer
A deoxyribose sugar, a phosphate group and one of four nitrogenous bases. -
Semi-conservative DNA replication
Which enzyme catalyses the addition of nucleotides to the new strand during DNA replication?
Show the answer
DNA polymerase. -
Semi-conservative DNA replication
Which enzyme joins Okazaki fragments on the lagging strand?
Show the answer
DNA ligase.
The 5 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Nucleotide structure and the bases | The pentose sugar, phosphate group and nitrogenous base of a nucleotide, the sugars that separate DNA from RNA, and which bases are purines and which are pyrimidines. | 14 |
| Polynucleotides, ADP and ATP | Phosphodiester bonds and the condensation and hydrolysis reactions that make and break a polynucleotide, together with the composition of ADP and ATP. | 11 |
| The structure of DNA | Complementary base pairing and the hydrogen bonds between strands, the antiparallel arrangement that produces the double helix, and how DNA is extracted. | 10 |
| Semi-conservative DNA replication | What semi-conservative means, the bonds helicase breaks, how DNA polymerase builds the new strand, why accuracy matters, and what a mutation is. | 10 |
| The genetic code, transcription and translation | The triplet code and what non-overlapping, degenerate and universal mean, RNA polymerase and the making of mRNA, and the roles of mRNA, tRNA and rRNA. | 13 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
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Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
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Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby sections
OCR A-Level Biology A Active Recall Guide
Every section, not just this one. 1,833 questions with their answers.