B1 H - Sample set 1 Q5
5) Diffusion, active transport and osmosis can be used to move substances into and out of cells.
(a) A student was investigating osmosis in potato cubes.
He used the following method:
(a) A student was investigating osmosis in potato cubes.
He used the following method:
- cut a potato into equal-sized cubes
- record the mass of each potato cube
- place each potato cube into different concentrations of salt solution
- remove the potato cubes after 30 minutes
- dry the potato cubes and record the final mass of each cube.
The method controls a number of variables.
(i) Name one other variable that needs to be controlled during the student’s investigation. (1)
(ii) Give a reason why the potato cube must be dried. (1)
(iii) Explain the conclusion that can be made about point Q on Figure 6. (2)
(iv) Give one way that the student could obtain more data to increase the accuracy of point Q. (1)
(b) Osmosis is one method that single-celled organisms, such as bacteria, use to obtain molecules from their environment.
Which of the following is a correct description of a process involving the transport of molecules? (1)
(i) Name one other variable that needs to be controlled during the student’s investigation. (1)
(ii) Give a reason why the potato cube must be dried. (1)
(iii) Explain the conclusion that can be made about point Q on Figure 6. (2)
(iv) Give one way that the student could obtain more data to increase the accuracy of point Q. (1)
(b) Osmosis is one method that single-celled organisms, such as bacteria, use to obtain molecules from their environment.
Which of the following is a correct description of a process involving the transport of molecules? (1)
(c) Figure 7 shows some Vibrio cholerae, the bacteria that cause cholera.
The length of one flagellum on Figure 7 is 68mm.
Calculate the length of the flagellum in µm. (3)
Calculate the length of the flagellum in µm. (3)
............................................................. µm
(Total for Question 5 = 9 marks)