CIE AS Biology

Topic Questions

Syllabus Edition

First teaching 2020

Last exams 2024

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5.1 Replication & Division of Nuclei & Cells

11 mark

A scientist counted 24 chromosomes in each of the root cells of a melon plant.

What is the diploid and haploid number of chromosomes for this species?

 

haploid

number

diploid

number

A

B

C

D

24

12

48

24

12

24

24

48

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21 mark

What is the role of a telomere? 

  • to enable correct coiling of genetic material

  • to aid the division of genetic material

  • to prevent the loss of genetic material

  • to initiate the replication of genetic material

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31 mark

When animal cells undergo mitosis, which structure organises spindle formation?

  • centrosome

  • nucleolus

  • centriole

  • centromere

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41 mark

Which of the following processes involve mitosis?

  • growth, repair and semi-conservative replication

  • repair, growth and asexual reproduction

  • reduction division, asexual reproduction and growth

  • repair, reduction division and asexual reproduction

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51 mark

Chromosomes in a nucleus are shown in the diagram below.

q5-cie-5-1

What are the structures R and S?

  R S

A

B

C

D

centromere

centromere

chromatid

chromatid

chromatid

centriole

centromere

centriole

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61 mark

Which statement about mitotic cell division is incorrect?

  • DNA is replicated semi-conservatively during mitosis

  • DNA is normally unchanged from one generation of cells to the next

  • The daughter cells not not have the potential to produce the same enzymes as the parent cell

  • The same quantity of DNA is distributed to the nuclei of two new cells

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71 mark

In which of the processes shown in the table is mitosis required?

  genetic variation increase in cell number replacement of damaged cells
A x
B x x
C x
D x x

 key 
contributes to process

x does not contribute to process

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81 mark

What is the end result of mitosis?

  • one dead cell and one new cell

  • two genetically identical clones of the parent cell

  • two cells with half the amount of DNA as the parent cell

  • one parent cell and two daughter cells, all identical

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91 mark

At what stage of the cell cycle would a cell be producing the most mRNA molecules?

  •  mitosis

  • G1 phase

  • S phase

  • G2 phase

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101 mark

Which statement does not describe a stem cell?

  • a cell that is required in the immune system

  • a cell only found in embryos

  • a cell that produces cells capable of differentiating

  • a cell that can divide an unlimited number of times

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11 mark

Which of the following requires only mitosis during their production?

  • root hairs

  • cancerous tissue

  • gametes

  • antibodies

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21 mark

The diagram shows a cell of an organism after replication division.

screenshot-2023-05-09-181930

What is the diploid number for this organism?

  • 10

  • 20

  • 40

  • 46

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31 mark

Around 250 billion red blood cells and 20 billion white blood cells are replaced each day. Blood cells are generated from stem cells in the bone marrow. 

What type of stem cells are found in human bone marrow?

  • pluripotent

  • totipotent

  • omnipotent

  • multipotent

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41 mark

What is the composition of telomeres and why?

  composition reason
A protein it is able to protect the DNA
B RNA it is made of different nucleotides to DNA
C C/G nucleotides only forms a high number of hydrogen bonds
D C/G/A/T nucleotides because telomeres are like the coding regions

 

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51 mark

Why does DNA condense into tightly packed chromosomes? 

  • easier to access genes

  • because it contains histone proteins

  • the volume of the cell is small

  • easier to separate the genetic material

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61 mark

Cells divide in response to a signal called a growth factor. Growth factors are proteins that bind to receptors on the surfaces of cells. 

At which point in the cell cycle will the growth factor bind?

screenshot-2023-05-09-201147

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71 mark

The DNA of cancer cells is mutated. 

Which of the following proteins would not cause cancer if mutated? 

  • DNA repair proteins

  • aquaporin channel proteins

  • cell death proteins

  • cell adhesion proteins

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81 mark

If a 14 cm long piece of string was packed into a 7 cm long tube, the packing ratio would be 2. The packing ratio is a useful measure of the degree of compactness achieved.

The linker DNA between nucleosomes is 72 base pairs long. Each base pair occupies a 0.52 nm length of the DNA double helix. Nucleosomes plus their linker DNA form a 10 nm wide fibre. 

What is the packing ratio of DNA in this form of chromatin?

  • 0.052

  • 37.44

  • 3.7

  • 13.8

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91 mark

Which cells contain telomerase?

1

B-lymphocytes

2

embryonic cells 

3

heart cells

  • 2 only

  • 1 and 3 only

  • 1 and 2 only

  • 1,2 and 3

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11 mark

Mitosis is required in which of the following processes?

1

2

3

cloning plasma cells

replacing damaged cells

producing gametes

  • 1 only

  • 2 only

  • 1 and 2 only

  • 1, 2 and 3

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21 mark

What processes during mitosis ensure that the genetic constitution of the cell is maintained?

1

2

3

4

dividing of centromeres longitudinally 

chromatids being pulled apart to opposite poles

parent cells replicate their DNA before mitosis begins

positioning the chromosomes on the equator of the spindle

  • 1, 2 and 3 only

  • 1, 2 and 4 only

  • 2, 3 and 4 only

  • 1, 2, 3 and 4

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31 mark

Tumors are formed from uncontrolled cell division of cancer cells.

Which statement describes the difference between a normal cell and a cancer cell?

  • only cancer cells have mutated DNA

  • cancer cells do not undergo cytokinesis

  • cancer cells have a shorter interphase

  • cancer cells do not have metaphase

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41 mark

The cell cycle is shown in the diagram below.

q14-cie-5-1

If dividing cells, cells are supplied with radioactive nucleotides, at which point will the nucleotides be incorporated into the chromosomes?

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51 mark

What properties does a human cell have just before it enters prophase?

  nuclear envelope present spindle present

number of chromatids

number of molecules of DNA in nucleus

A

B

C

D

no

yes

yes

yes

yes

no

yes

no

46

92

46

92

46

92

92

46

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61 mark

The statements below are about two genes involved in breast cancer.

  • the BRAC1 gene codes for a protein that stops the growth of breast cancer cells
  • the p53 gene codes for a protein that suppresses tumours

Which genetic combination is most likely to result in breast cancer?

  gene
  BRAC1 p53
A
B X
C X
D X X

Key:
= normal active gene
x = mutated gene

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71 mark

DNA replication is promoted by chromosome telomeres and are not completely replaced during mitosis. 

However, substance X is known to completely replace telomeres during mitosis.

What will be the effect of growing a cell culture with and without substance X?

  with substance X without substance X
A

cell division stops immediately

cells continuously divide
B

cells continuously divide

cell division eventually slows and stops
C cell division eventually slows and stops

cell division stops immediately

D cells divide quicker

cells continuously divide

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81 mark

Radioactive thymine is supplied to mammalian skin cells in tissue culture.

At which stage in the cell cycle will the thymine be used in the nuclei?

  • interphase

  • metaphase

  • prophase

  • anaphase

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91 mark

The risk of developing a cancerous tumour is increased by exposure to which of the following?

  ultraviolet light viruses carbon monoxide X-rays
A x
B x
C x x
D x x

key

increases risk

x does not increase risk

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101 mark

Mice in laboratories had their p53 genes switched off. These mice went on to develop tumours.

When their p53 genes were switched on again, the tumour cells stopped dividing and died within a few days. Healthy cells in the mice were unaffected. 

What do these observations suggest?

  • the p53 gene acts as a tumour suppressor gene

  • p53 protein causes all cells to die

  • the p53 gene encourages the growth of tumours

  • p53 protein speeds up the mitotic cell cycle the p53

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