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IB Biology HLD2.1 Cell and nuclear divisionQuestion Bank

D2.1 Cell and nuclear division

Question 1

[Maximum number: 13]

Mitosis in cancerous tissues is uncontrolled and the number of cells undergoing mitosis increases exponentially. Rapidly dividing cells in root tips can be used as a model for studying the effects of anticancer drugs. Aqueous extracts of the fruit of avocado (Persea americana) and the leaves of crepe jasmine (Tabernaemontana divaricata) have been shown to be toxic to some human cancer cell lines. Root tips of the broad bean (Vicia faba) were exposed to these aqueous plant extracts over a range of concentrations.

The mitotic index is the percentage of cells examined undergoing mitosis. The table shows the numbers of broad bean root cells examined and the mitotic indices over a range of plant extract concentrations.

Table

Question 1(a)

Question 1(a)(i)

(a)
(i)

Calculate the number of cells undergoing mitosis using 100 ppm of crepe jasmine extract.

[ 1 ]

Question 1(a)(ii)

(ii)

Describe the effect of avocado extract on mitotic index.

[ 1 ]

Question 1(b)

(b)

Compare and contrast the effect of increasing extract concentration on the mitotic indices for the two plant extracts.

[ 3 ]

Question 1(c)

(c)

The percentage of cells in different stages of mitosis in the root tips was also recorded.

Question image

Outline the effect of avocado extract concentration on the percentage of cells in the different stages of mitosis.

[ 2 ]

Question 1(d)

(d)

Using both the table of mitotic indices and the bar charts, deduce whether these extracts contain chemicals that block mitosis in broad bean root tips.

[ 3 ]

Question 1(e)

(e)

The mechanism of action of vinblastine, an anticancer drug, was investigated over a range of concentrations. Vinblastine is an alkaloid isolated from the periwinkle plant (Catharansus roseus). The percentage of cells in mitosis and ratio of anaphase to metaphase in cells exposed to this drug in vitro for a fixed time were recorded. The data are displayed in two graphs.

Question image
Question image

By referring to both graphs, evaluate the hypothesis that vinblastine targets cells in mitosis and prevents them from completing the process.

[ 3 ]

Question 1

Question 1(a)

(a)

The photomicrograph shows a section of onion (Allium cepa) root tip cells.

× 1000

× 1000

[ 2 ]

Question 1(a)(i)

(i)

Describe how a mitotic index could be obtained from this image.

[ 2 ]

Question 1(b)

(b)

Cadmium is a heavy metal that can cause environmental problems. Cadmium ions are released from various human activities such as the release of sewage sludge, mining and industrial processes. Plants take up cadmium ions and they enter food chains.

A study was carried out to look at the effect of various concentrations of cadmium ions on the mitotic index of the apical meristem of root cells from 4-day-old wheat (Triticum aestivum) seedlings.

Question image
[ 2 ]

Question 1(b)(i)

(i)

State the effect of cadmium ion concentration on the mitotic index of root cells from wheat seedlings.

[ 1 ]

Question 1(b)(ii)

(ii)

Suggest the effect the change in mitotic index would have on the wheat plant.

[ 1 ]

Question 3

[Maximum number: 1]

Which processes are involved in the development of cancer?

I. Mutations occur in oncogenes.
II. Oncogenes prevent cancer.
III. Oncogenes affect cell cycle regulatory proteins.

A

I and II only

B

I and III only

C

II and III only

D

I, II and III

Question 4

[Maximum number: 1]

When does DNA replication occur?

A

S phase of interphase

B

Early prophase

C

G phase of interphase

D

Late prophase

Question 4

[Maximum number: 1]

What would show that a person has developed metastatic cancer?

A

Alveolus cells forming a tumour in the lungs

B

Cancer cells producing the skin pigment melanin in the liver

C

A tumour in the prostate gland increasing levels of prostate-specific antigen

D

Cancerous lymphocytes in blood plasma

Question 4

[Maximum number: 1]

In which stage of the cell cycle are chromosomes duplicated?

Question image
A

G1 phase

B

G2 phase

C

S phase

D

Mitosis

Question 4

[Maximum number: 1]

Students examined micrographs and counted cells in the different stages of mitosis as well as those cells with no visible chromosomes. The table shows their results.

Table

What is the mitotic index?

A

0.2

B

0.4

C

0.6

D

0.7

Question 4

[Maximum number: 1]

The following events occur in mitosis.

X: Attachment of spindle microtubules to centromeres
Y: Movement of sister chromatids to opposite poles
Z: Supercoiling of chromosomes
What is the correct sequence of events?

A

X→Z→Y\mathrm{X} \rightarrow \mathrm{Z} \rightarrow \mathrm{Y}

B

X→Y→Z\mathrm{X} \rightarrow \mathrm{Y} \rightarrow \mathrm{Z}

C

Z→X→Y\mathrm{Z} \rightarrow \mathrm{X} \rightarrow \mathrm{Y}

D

Z→Y→X\mathrm{Z} \rightarrow \mathrm{Y} \rightarrow \mathrm{X}

Question 4

[Maximum number: 1]

The following shows a micrograph.

Question image

How many cells are in metaphase?

A

2

B

3

C

5

D

7

Question 4

[Maximum number: 1]

The concentrations of cyclins rise and fall in cells at certain times.

Question image

What times are these?

A

Day and night

B

Seasons of the year

C

Stages of mitosis and interphase

D

Developmental stages in the life cycle

0 selected