Organisation of the OrganismCambridge IGCSE Biology: Topic test

20 questions, 54 marks

Cambridge IGCSE Biology

Organisation of the Organism topic test

Total 54 marks

Name

Class

Date

1
A student examines two prepared microscope slides: one showing cells from the epidermis of a rose petal, and one showing cells scraped from the lining of a fish's gill. Both slides are viewed at the same magnification.
(a)
Which structure would the student expect to see in the rose petal cells but not in the fish gill cells?
[1 mark]
ACell wall
BNucleus
CCytoplasm
DCell membrane
(b)
Which structure would the student expect to find in both the rose petal cell and the fish gill cell?
[1 mark]
ACell wall
BMitochondria
CChloroplast
DPermanent vacuole
(c)
State two structures that would be present in the rose petal cell but absent from the fish gill cell.
[2 marks]
Total for question 1: 4 marks
2
A student examines an image of a bacterial cell taken with an electron microscope. The cell has a cell wall, a cell membrane, cytoplasm containing ribosomes, and one long circular strand of DNA that is not enclosed in a nucleus. Several small rings of DNA, separate from the main circular DNA, are also visible.
(a)
What is the name given to the small rings of DNA found separately from the main circular DNA in the bacterial cell?
[1 mark]
AChromosomes
BRibosomes
CPlasmids
DMitochondria
(b)
Which structure, found in plant and animal cells, is absent from this bacterial cell?
[1 mark]
ACell wall
BCytoplasm
CRibosomes
DNucleus
(c)
Explain how the genetic material of this bacterial cell differs from the genetic material of a plant or animal cell.
[2 marks]
Total for question 2: 4 marks
3
A biology class studies three specialised cells under the microscope: a cell lining the trachea with hair-like projections that beat to sweep mucus upwards; a long thin cell from a plant root with a large surface area for absorbing water and mineral ions from the soil; and a small, streamlined cell with a tail, produced in large numbers, that swims to reach an egg cell.
(a)
State the name and one function of each of the three specialised cells described above.
[3 marks]
(b)
Explain how the structure of the root hair cell and the structure of the sperm cell are each adapted to their function.
[4 marks]
Total for question 3: 7 marks
4
A student is studying the human digestive system. She learns that the stomach wall contains several different types of cell, including gland cells that secrete digestive juice and muscle cells that contract to churn food. These cells are organised together with connective tissue and a lining layer to form the stomach wall, and the stomach works together with the oesophagus, small intestine and other organs as part of a larger body system.
(a)
Define the terms cell, tissue, organ and organ system, using an example from the stomach for each term.
[6 marks]
(b)
The gland cells and muscle cells in the stomach wall are both specialised, but they are very different from each other in structure. Explain what is meant by a specialised cell, and explain, in general terms, how cells become specialised for particular functions in a multicellular organism such as a human.
[6 marks]
Total for question 4: 12 marks
5
A student draws a diagram of a palisade mesophyll cell from a leaf. In her drawing, the cell measures 84 mm in length. She has been told that the actual length of the real cell is 0.14 mm.
(a)
Which formula is used to calculate magnification?
[1 mark]
Amagnification = image size ÷ actual size
Bmagnification = actual size ÷ image size
Cmagnification = image size × actual size
Dmagnification = actual size − image size
(b)
What is the magnification of the student's drawing?
[1 mark]
A60
B600
C6000
D6
(c)
The student then draws a second cell at the same magnification (×600), and this drawing measures 90 mm in length. Calculate the actual length of this second cell, in mm, showing your working.
[2 marks]
Total for question 5: 4 marks
6
A technician measures a yeast cell under a light microscope and calculates that its actual diameter is 8 µm. She wants to compare this with the actual diameter of a plant cell, which she has calculated to be 0.05 mm.
(a)
How many micrometres (µm) are there in 1 millimetre (mm)?
[1 mark]
A10
B100
C1000
D10000
(b)
What is the actual diameter of the plant cell (0.05 mm) expressed in micrometres?
[1 mark]
A5 µm
B500 µm
C5000 µm
D50 µm
(c)
Using your answer to part (b), state which of the two cells (the yeast cell or the plant cell) has the larger actual diameter, and calculate how many times larger it is.
[2 marks]
Total for question 6: 4 marks
7
A student is given descriptions of three cell structures found in a plant cell: a structure containing chlorophyll where photosynthesis occurs; small structures in the cytoplasm, not enclosed by a membrane, where proteins are made; and a fluid-filled sac that stores cell sap and helps keep the cell firm.
(a)
Name the three cell structures described above.
[3 marks]
(b)
State the function of the cell membrane and the function of mitochondria, and explain why both of these structures are essential for a plant cell to survive, even though neither was described above.
[4 marks]
Total for question 7: 7 marks
8
A researcher compares a bacterial cell, a red blood cell and a palisade mesophyll cell using an electron microscope. The bacterial cell has an actual diameter of about 1 µm, the red blood cell about 8 µm, and the palisade mesophyll cell about 40 µm. The researcher draws a scale diagram of the palisade mesophyll cell at a magnification of ×2000.
(a)
Compare the structures you would expect to find in the bacterial cell with those you would expect to find in the palisade mesophyll cell, explaining at least three differences.
[6 marks]
(b)
Calculate the length, in mm, that the palisade mesophyll cell (actual diameter about 40 µm) would appear as in the researcher's scale diagram, drawn at a magnification of ×2000, showing your working and giving your answer with an appropriate unit.
[6 marks]
Total for question 8: 12 marks

End of questions