Organisation of the Organism
5 questions, 38 marks, every one with its mark scheme, 1 of them Higher Tier or Extended only.
Or open them one at a time, as you finish each question.
Question 1
9 marksA student uses a light microscope to look at cells from a leaf of a pondweed and cells from the lining of a human cheek.
Complete the table to give the function of each structure.
| Structure | Function |
|---|---|
| Nucleus | |
| Cytoplasm | where chemical reactions take place |
| Cell membrane | |
| Mitochondria | |
| Ribosomes |
Mark scheme
- contains DNA1
- controls what goes into and out of the cell1
- aerobic respiration1
- protein synthesis1
The pondweed cells have a cell wall but the cheek cells do not.
State two functions of the cell wall.
Mark scheme
- provides support1
- prevents the cell bursting1
Name the substance that makes up the cell wall of a pondweed cell.
Mark scheme
- cellulose1
State two functions of the large vacuole in a pondweed cell.
Mark scheme
- contains cell sap1
- stores water1
Question 2
7 marksLactobacillus is a bacterium used to make yoghurt.
Some other bacteria have a flagellum.
What does a bacterium use its flagellum for?
Mark scheme
- movement1
Lactobacillus cells contain plasmids.
State one use of plasmids by scientists.
Mark scheme
- used in genetic modification1
Compare the structure of a Lactobacillus cell with the structure of a palisade mesophyll cell.
Mark scheme
Any 5 from:
- both have a cell wall1
- both have a cell membrane1
- both have cytoplasm1
- both have ribosomes1
- bacterium has circular DNA free in the cytoplasm1
- bacterium has no nucleus1
- bacterium has plasmids1
- bacterium has no mitochondria1
- palisade mesophyll cell has chloroplasts1
- palisade mesophyll cell has a large permanent vacuole1
- palisade mesophyll cell has a cellulose cell wall1
Question 3
11 marksAnimals and flowering plants contain many types of specialised cell.
Complete the table to give the function of each specialised cell.
| Specialised cell | Function |
|---|---|
| Ciliated cell in the trachea | |
| Red blood cell | |
| Neurone | |
| Root hair cell | absorption |
Mark scheme
- move mucus1
- transports oxygen1
- conduction of electrical impulses1
Define the term tissue.
Mark scheme
- a group of cells with similar structures1
- working together to perform a shared function1
Complete the table to give the level of organisation of each structure.
| Structure | Level of organisation |
|---|---|
| a layer of palisade mesophyll cells | |
| a leaf | |
| a sperm cell | |
| the circulatory system |
Mark scheme
- tissue1
- organ1
- cell1
- organ system1
Define the term organ.
Mark scheme
- a structure made up of a group of tissues1
- working together to perform a specific function1
Question 4
5 marksA student makes a drawing of a leaf from a moss plant.
Write the equation that links magnification, image size and actual size.
Mark scheme
- magnification = image size ÷ actual size1
On the drawing the leaf measures 68 mm. The real leaf measures 4.0 mm.
Calculate the magnification of the drawing.
Mark scheme
- 68 ÷ 4.01
- ×171
Do not accept: ×17 mm
The student also has a photograph of a dust mite. The length of the mite on the photograph is 45 mm. The magnification of the photograph is ×150.
Calculate the actual length of the dust mite.
Give the unit of your answer.
Mark scheme
- 45 ÷ 1501
- 0.3 mm1
Question 5
Extended6 marksA student measures cells on photographs taken with a microscope.
A cheek cell has an actual width of 60 µm.
Convert 60 µm into millimetres.
Mark scheme
- 0.06 mm1
The width of the same cheek cell on the photograph is 48 mm.
Calculate the magnification of the photograph.
Mark scheme
- 48 ÷ 0.061
- ×8001
On another photograph, the image of a bacterial cell is 36 mm long. The magnification of this photograph is ×12 000.
Calculate the actual length of the bacterial cell in µm.
Mark scheme
- 36 ÷ 12 000 = 0.003 mm1
- 0.003 × 10001
- 3 µm1