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4 Cell membranes and transport

Click on the correct answer to each question.

1 The diagram shows a small part of a cell surface membrane.

1

2

3

4

Which regions are hydrophobic?

A 1 and 2 only

B 1 and 4 only

C 2 and 3 only

D 3 and 4 only

2 The diagram shows part of a cell surface membrane. In addition to the molecules shown, cholesterol is also present.

D

C

B

A

In which region is cholesterol found?

Multiple-choice test

© Cambridge University Press 2013 Multiple-choice test: Chapter 4

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3 Which component of a cell surface membrane allows the movement of ions across the membrane?

A cholesterol

B fatty acids

C phospholipid

D protein

4 The molecules which make up biological membranes have different functions.

Which row matches molecules with their functions?

Separating dissolved ions

Transporting ions

Stabilising the hydrophobic layer

Recognising self and non-self

A cholesterol glycoprotein phospholipid protein

B glycolipid phospholipid protein cholesterol

C phospholipid protein cholesterol glycoprotein

D protein cholesterol glycoprotein phospholipid

5 A substance moves into a cell through a protein pore.

Which of the following describes this movement?

A an ion moving against its concentration gradient by active transport

B glucose moving down its concentration gradient by diffusion

C oxygen moving against its concentration gradient by facilitated diffusion

D carbon dioxide moving against its concentration gradient by osmosis

Multiple-choice test: Chapter 4 © Cambridge University Press 2013

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6 Which of the following correctly describes the movement of water by osmosis?

A from a region of higher water potential to a region of lower water potential through a fully permeable membrane

B from a region of higher water potential to a region of lower water potential through a partially permeable membrane

C from a region of lower water potential to a region of higher water potential through a fully permeable membrane

D from a region of lower water potential to a region of higher water potential through a partially permeable membrane

7 Which of the processes that transport materials across a cell surface membrane require energy from the cell’s supply of ATP?

Key: = requires energy from ATP = does not require energy from ATP

Endocytosis Exocytosis Facilitated diffusion Osmosis

A

B

C

D

8 A protein is synthesised by a ribosome in an animal cell.

What is the sequence of events leading to the secretion of the protein by exocytosis?

1 protein modified by the Golgi apparatus2 protein enters the endoplasmic reticulum3 secretory vesicles fuse with the cell surface membrane4 secretory vesicles formed by the Golgi apparatus5 vesicles bud off from the endoplasmic reticulum

A 1 → 2 → 5 → 4 → 3

B 2 → 5 → 1 → 4 → 3

C 3 → 4 → 1 → 5 → 2

D 5 → 4 → 3 → 2 → 1

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9 Examples of the bulk transport of materials into or out of cells are listed.

1 white blood cell engulfing a bacterium2 plant cell building up its cell wall3 pancreas cell releasing digestive enzymes4 ovum taking up liquid nutrients from a follicle cell

Which are examples of exocytosis?

A 1 and 2 only

B 1 and 4 only

C 2 and 3 only

D 3 and 4 only

10 A small piece of plant tissue was placed into each of three solutions, P, Q and R. After one hour, the tissues were examined using a light microscope and the appearance of the cells was recorded.

P Q R

What conclusion can be made about the water potentials of the three solutions?

A The water potential of P is greater than that of R.

B The water potential of Q is greater than that of R.

C The water potential of R is greater than that of P.

D The water potential of Q is greater than that of P.

Multiple-choice test: Chapter 4 © Cambridge University Press 2013