CellsIB MYP Biology: Topic test

20 questions, 54 marks

IB MYP Biology

Cells topic test

Total 54 marks

Name

Class

Date

1
Researchers in Iceland have found a single-celled organism living in a hot spring. Under the electron microscope its cell has a cell wall, a loop of DNA lying free in the cytoplasm and several small rings of DNA, but no nucleus.
(a)
What are the small rings of DNA called?
[1 mark]
AChloroplasts
BPlasmids
CVacuoles
DRibosomes
(b)
Which observation shows that this is not an animal cell or a plant cell?
[1 mark]
AIt has a cell wall.
BIt contains ribosomes.
CIts DNA is not enclosed in a nucleus.
DIt has a cell membrane.
(c)
Describe two ways in which this cell differs from a plant cell.
[2 marks]
Total for question 1: 4 marks
2
A neuroscientist in Buenos Aires studies a nerve cell that runs from the base of a person's spine to the big toe. The cell is almost a metre long. It has one very long, thin fibre and branched endings.
(a)
What is the main function of a nerve cell?
[1 mark]
ATo carry electrical impulses from one part of the body to another
BTo carry oxygen around the body
CTo absorb water and minerals from the soil
DTo destroy pathogens by engulfing them
(b)
Which feature of this cell allows it to carry impulses over a long distance?
[1 mark]
AIts biconcave shape
BIts large number of chloroplasts
CIts tail
DIts long, thin fibre
(c)
Explain how two structural features of the nerve cell help it to do its job.
[2 marks]
Total for question 2: 4 marks
3
A student studies a pollen grain from a lily using a light microscope. She makes a drawing of the grain that is 60 mm wide. She works out that her drawing is magnified ×400.
(a)
Calculate the actual width of the pollen grain in micrometres (µm). Show your working.
[3 marks]
(b)
Describe how the student should use a light microscope to focus on the slide safely, starting with the lowest-power objective lens.
[4 marks]
Total for question 3: 7 marks
4
Researchers in Stockholm are developing a treatment for heart muscle that has been damaged by a heart attack. They plan to take a small number of stem cells, grow them in the laboratory into millions of heart muscle cells, and inject these into the damaged heart. The stem cells could come from a donated human embryo or from the patient's own bone marrow.
(a)
Explain how a small number of stem cells could be turned into millions of new heart muscle cells.
[6 marks]
(b)
Discuss whether doctors should use embryonic stem cells rather than the patient's own adult stem cells for this treatment.
[6 marks]
Total for question 4: 12 marks
5
A student in Lagos examines a cross-section of a spinach leaf. She identifies a layer of palisade tissue that carries out photosynthesis, a covering of epidermal tissue, and veins that contain xylem tissue.
(a)
What is a tissue?
[1 mark]
AA group of similar cells that work together to do a job
BA group of organs that work together
CA single cell with a special structure
DA group of different organ systems
(b)
Why is the leaf described as an organ?
[1 mark]
AIt is made of only one type of cell.
BIt is made of different tissues that work together to do a job.
CIt is made of several organ systems.
DIt is a single cell that has been specialised.
(c)
Describe how palisade cells, palisade tissue and the leaf are related to one another.
[2 marks]
Total for question 5: 4 marks
6
A woman aged 50 in Seoul walks briskly for 30 minutes every day. Her doctor says that regular exercise lowers the risk of heart disease and of type 2 diabetes, which are both non-communicable diseases.
(a)
What is a non-communicable disease?
[1 mark]
AA disease caused by a virus
BA disease that can be passed from one person to another
CA disease that is not caused by a pathogen and cannot be passed on
DA disease caused by a fungus
(b)
How does regular exercise reduce the risk of coronary heart disease?
[1 mark]
AIt makes the heart muscle smaller.
BIt increases the amount of fat in the blood.
CIt stops the blood from reaching the lungs.
DIt strengthens the heart muscle and helps to keep the body mass healthy.
(c)
Explain how regular exercise can reduce the risk of type 2 diabetes.
[2 marks]
Total for question 6: 4 marks
7
A student places small paper discs on an agar plate that has been spread with harmless bacteria. Disc W is soaked in water. Disc X is soaked in antibiotic X and disc Y is soaked in antibiotic Y. After two days, a clear ring has formed around each antibiotic disc where the bacteria have been killed. The diameters of the rings in three repeats were 12 mm, 14 mm and 13 mm for antibiotic X, and 6 mm, 5 mm and 7 mm for antibiotic Y. There was no clear ring around disc W.
(a)
Calculate the mean diameter of the clear ring for each antibiotic and state which antibiotic was more effective.
[3 marks]
(b)
Explain the purpose of disc W and describe three safety precautions the student should take in this investigation.
[4 marks]
Total for question 7: 7 marks
8
In a town in northern India, health workers are trying to reduce cases of tuberculosis (TB), a lung disease caused by bacteria that spread in droplets when an infected person coughs. A TB vaccine is offered to every baby. Many adults in the town smoke heavily, and smokers are more likely to develop serious lung disease.
(a)
Explain how vaccinating babies protects them from TB, and how it can also protect people who have not been vaccinated.
[6 marks]
(b)
Discuss whether the town should spend its limited health budget on vaccinating babies or on helping adults to stop smoking.
[6 marks]
Total for question 8: 12 marks

End of questions

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).