Biology 9700 · AS & A Level
Structure of nucleic acids and replication of DNA
100 practice questions on Structure of nucleic acids and replication of DNA, with worked solutions and instant marking.
Of the structures listed, how many normally have genetic material containing telomeres? • bacterial cell • chloroplast • mitochondrion • nucleus
Feb/March 2016
In a DNA molecule, $21.2\%$ of the bases are cytosine. What percentage would adenine be?
Feb/March 2016
Fig. 2.1 illustrates a root tip cell during interphase.
Feb/March 2016
Which statement concerning nitrogenous bases is correct?
Feb/March 2017
Fig. 1.1 shows a diagram of a chromosome taken from a dividing cell.
Feb/March 2017
Cholera is an infectious disease brought about by a bacterium.
Feb/March 2017
Catalase is an enzyme that speeds up the decomposition of hydrogen peroxide, a toxic waste product of metabolism. The reaction is $2\text{H}_2\text{O}_2 \xrightarrow{\text{catalase}} 2\text{H}_2\text{O} + \text{O}_2$. Fig. 3.1 presents the findings of an investigation into how hydrogen peroxide concentration affects the rate of the catalase-controlled reaction, both in the absence of inhibitors and in the presence of two different inhibitors.
Feb/March 2017
The diagram shows an ATP molecule. What do the labels P, Q and R represent in ATP?
Feb/March 2018
In a cell that is dividing, DNA replication takes place before mitosis.
Feb/March 2018
Mitosis in plant and animal cells produces two genetically identical daughter cells from one parent cell.
Feb/March 2019
The diagram shows a nucleotide with adenine. Which of the following statements about this nucleotide are correct?
Feb/March 2022
Which eukaryotic cell structures each contain nucleic acids?
Feb/March 2022
Fig. 2.1 shows a cell during one of the key stages of mitosis in the mitotic cell cycle.
Feb/March 2022
The PDx1 protein is present in many different animal species, where it is considered vital for normal metabolism. In sand rats, the gene that codes for the PDx1 protein contains a much smaller proportion of A and T nucleotides than PDx1 genes from other animals. It has been difficult to determine the full DNA sequence of the PDx1 gene in sand rats. Sequencing requires removing nucleotides one at a time from single-stranded DNA. What might explain the difficulty in determining the DNA sequence of the PDx1 gene in sand rats?
Feb/March 2023
Which of the following statements are true for every nucleotide?
Feb/March 2024
In a circular DNA molecule containing 2700 base pairs, how many phosphodiester bonds are there?
Feb/March 2024
Which diagram shows one of the DNA base pairs correctly?
Feb/March 2025
DNA is found in both eukaryotic cells and prokaryotic cells.
Feb/March 2025
Fig. 6.1 presents photomicrographs of separate cells from the onion root tip, $\textit{Allium sp.}$, taken at different points in the mitotic cell cycle.
Feb/March 2025
What outcome would be obtained by analysing a section of a DNA molecule?
May/June 2010
What would analysing a segment of a DNA molecule show?
May/June 2010
Name the phase of the mitotic cell cycle in which DNA replication happens.
May/June 2010
Fig. 1.1 shows a photomicrograph of an onion, Allium cepa, root tip, with cells visible in interphase and at different stages of mitosis.
May/June 2011
Fig. 1.1 depicts a stage within the mitotic cell cycle of an animal cell.
May/June 2011
Fig. 6.1 presents a section of a DNA molecule.
May/June 2012
What is the greatest possible number of hydrogen bonds in a DNA strand section containing 700 base pairs?
May/June 2013
What is the greatest number of hydrogen bonds possible in a length of DNA containing 700 nucleotides?
May/June 2013
Which diagram shows a correct base pair in DNA?
May/June 2014
Which nucleic acid bases are classed as pyrimidines?
May/June 2014
A DNA fragment that was 15 base pairs long was examined in order to determine how many nucleotides were present in each polynucleotide strand. Some of the findings are shown below. How many nucleotides containing adenine (A) were in strand 2?
May/June 2014
Fig. 1.1 displays the structures of four biological molecules A, B, C and D.
May/June 2014
Which row accurately identifies the characteristics of DNA and RNA molecules?
May/June 2015
A DNA molecule is composed of two polynucleotide strands. Which description is correct?
May/June 2015
The diagram illustrates part of a DNA molecule. What number of hydrogen bonds are present in keeping these DNA strands joined together?
May/June 2015
Which row gives the correct description of adenine?
May/June 2015
A student studied root growth in broad bean, Vicia faba. Sections were cut from the root tip of this plant and examined using a light microscope. Fig. 1.1 shows a photomicrograph of one of the sections. The cell labelled D is in interphase.
May/June 2015
DNA replication is a key event in the cell cycle.
May/June 2015
Which statements concerning complementary base pairing are correct?
May/June 2016
A DNA fragment that was 18 base pairs in length was examined to determine how many nucleotide bases were in each of the polynucleotide strands. A few of the findings are given below. How many nucleotides containing thymine were found in strand 2?
May/June 2016
Glycogen synthase is one of the enzymes that take part in glycogen synthesis. The monomer unit of the glycogen polymer is $\alpha$-glucose.
May/June 2016
What type of sugar and what type of bond are present in a DNA molecule?
May/June 2017
The DNA in prokaryotes is not linked to proteins and is arranged in a circular molecule. Which statement explains the way DNA in eukaryotes differs from DNA in prokaryotes?
May/June 2017
Which row shows the correct information for adenine?
May/June 2017
Which of these statements about nucleotides is correct?
May/June 2017
Describe how DNA replication takes place.
May/June 2017
Which row shows the correct information for guanine?
May/June 2018
A section of a DNA molecule has the coding sequence AGGCAATGGC. Which of the following statements are correct? 1. There are 3 pyrimidines in this coding sequence. 2. In the double-stranded DNA for this section, there are 26 hydrogen bonds between complementary bases. 3. This double-stranded DNA section contains 20 sugar-phosphate bonds.
May/June 2018
The diagram illustrates the structural outlines of two nucleotide bases found in DNA. These two bases are joined by two hydrogen bonds, which are drawn as dashed lines. Which row correctly names these two nucleotide bases?
May/June 2018
In 1953, James Watson and Francis Crick published information on the structure of DNA. They drew on experimental findings from other scientists to help determine the structure, then constructed a model of part of a DNA molecule using wire and metal pieces, with clamp stands supporting the model. This is shown in Fig. 2.1.
May/June 2018
Identify the nucleic acid bases that are purines.
May/June 2019
Which statement gives the correct description of base pairing in a DNA molecule?
May/June 2019
Which row gives the correct properties of the nitrogenous base thymine?
May/June 2019
DNA that is located in the nucleus is called nuclear DNA.
May/June 2019
Fig. 1.1 is a diagram illustrating the structure of part of a DNA molecule.
May/June 2019
Which statement is correct about thymine?
May/June 2020
A short DNA fragment that was 15 base pairs in length was examined in order to determine the number of nucleotide bases in each polynucleotide strand. Some of the outcomes are shown below. How many nucleotides containing guanine were present in strand 1?
May/June 2020
Certain viruses contain single-stranded DNA as their genetic material. To fit inside the protein coat, this DNA molecule must be folded. Which statements about single-stranded DNA are correct?
May/June 2020
Fig. 2.1 depicts several stages of the cell cycle in the meristematic tissue at the root tip of a plant. Table 2.1 identifies three of these stages as P, Q and R.
May/June 2020
The mitotic cell cycle in dividing cells is tightly regulated.
May/June 2020
Blood cells originate from tissue stem cells in the bone marrow. These bone marrow stem cells pass through several mitotic cycles before developing into mature blood cells that function properly. Fig. 5.1 illustrates the three principal stages of the cell cycle.
May/June 2020
Which cell structures have nucleic acid in them?
May/June 2021
The diagram shows a nucleotide that contains thymine. Which of the following statements about this nucleotide are correct?
May/June 2021
Fig. 1.1 shows a photomicrograph of one area of eukaryotic tissue. Several of the cells are at mitotic stages.
May/June 2021
The ideal point in a mitotic cell cycle for getting a sharp view of chromosomes is the metaphase stage. Fig. 6.1 shows a scanning electron micrograph of a set of human chromosomes at metaphase.
May/June 2021
A circular bacterial DNA molecule contains 2 600 150 base pairs. Adenine accounts for 26% of the bases. How many cytosine bases are present in the DNA molecule?
May/June 2022
Which statement about the structure of DNA is correct?
May/June 2022
The diagram illustrates a section of a DNA molecule. Which label is the correct one?
May/June 2022
What substance is found in all viruses, all prokaryotes and all eukaryotes?
May/June 2023
Which polymers occur in every virus and in all prokaryotes?
May/June 2023
Which molecules form ATP’s structure?
May/June 2023
A DNA fragment, 19 base pairs in length, was examined to determine the number of nucleotide bases in each polynucleotide strand. Some results are shown. How many cytosines were present in strand 1?
May/June 2023
Which cell structures are found to contain nucleic acid?
May/June 2023
In humans, the gene that codes for catalase is located on chromosome 11.
May/June 2023
Nucleotide and nucleoside analogues are drugs used in therapy that have structures similar to the nucleotides or nucleosides present in RNA and DNA. A nucleoside consists of a nitrogenous organic base (base) joined to a pentose sugar.
May/June 2023
Cells within a tissue are often at different points in the cell cycle. Fig. 1.1 depicts cells at various stages of the cell cycle.
May/June 2023
The diagrams illustrate the chemical structures of four bases. Which diagrams represent thymine and cytosine?
May/June 2024
The diagram illustrates a typical animal cell. In which part would nucleic acids be found?
May/June 2024
In interphase of the cell cycle, individual chromosomes are not visible inside the nucleus. At this stage, the genetic material is called chromatin.
May/June 2024
DNA and RNA belong to the group of polynucleotides.
May/June 2024
A DNA molecule with two strands was examined, and adenine made up 29% of its nucleotide bases. What percentage of its nucleotide bases is cytosine?
May/June 2025
At times, hydrogen bonds are made briefly between the bases on two RNA strands. How many hydrogen bonds are produced when guanine and uracil each pair with their complementary base?
May/June 2025
What correctly states how many and what kind of bonds link cytosine and guanine in a DNA molecule?
May/June 2025
Fig. 3.1 shows a scanning electron micrograph of two human chromosomes at a stage in the mitotic cell cycle.
May/June 2025
DNA was extracted from the salivary glands of a fruit fly and from a human cheek cell. In what way did the DNA molecules differ?
Oct/Nov 2010
The table gives the percentages of nitrogenous bases in four nucleic acid samples. Which base is adenine?
Oct/Nov 2010
The table displays the percentages of bases in DNA from different cell types. What valid deduction can be made from these data?
Oct/Nov 2010
DNA was extracted from the salivary glands of a fruit fly and from a human cheek cell. In what way did the DNA molecules differ?
Oct/Nov 2010
The table gives the percentages of nitrogenous bases in four nucleic acid samples. Which base is adenine?
Oct/Nov 2010
Fig. 4.1 shows the structure of deoxyribose sugar. State how the deoxyribose structure shown in Fig. 4.1 differs from the ring structure of $\alpha$-glucose.
Oct/Nov 2011
Which characteristics of DNA allow it to satisfy these requirements as a molecule of inheritance?
Oct/Nov 2012
State the structural features in DNA that contribute to its stability.
Oct/Nov 2012
A DNA segment 19 base pairs in length was studied to determine the number of nucleotide bases in each polynucleotide strand. Some of the results are shown. How many nucleotides containing C were present in strand 1?
Oct/Nov 2013
What is the least number of hydrogen bonds in a DNA strand section containing 700 base pairs?
Oct/Nov 2013
Fig. 1.1 depicts a cell from a female fruit fly, Drosophila melanogaster, at one stage of mitosis.
Oct/Nov 2013
The diagram illustrates part of a DNA molecule. Which regions include phosphate groups?
Oct/Nov 2014
What type of sugar and which types of bonds are present in a DNA molecule?
Oct/Nov 2014
A DNA fragment 15 base pairs in length was examined in order to determine how many nucleotides were on each polynucleotide strand. Some of the findings are shown below. The table gives the numbers of nucleotide bases A, C, G and T for strand 1 and strand 2. Strand 1 contains 6 cytosine bases and 3 thymine bases. Strand 2 contains 4 thymine bases. How many nucleotides containing guanine were present in strand 1?
Oct/Nov 2014
A student prepared thin sections from a root tip of $\textit{Allium cepa}$ and stained them so the chromosomes could be seen. Fig. 4.1 shows a photomicrograph of part of one of these sections. Table 4.1 outlines chromosome behaviour and the changes in the nuclear envelope during a mitotic cell cycle in the root tip of $A.\,cepa$.
Oct/Nov 2014
Which row identifies two pairs of nucleotide bases in a DNA molecule?
Oct/Nov 2015
Which row gives the correct description of cytosine?
Oct/Nov 2015