Cell membranes and transport — AS & A Level Biology (9700) questions by topic

The cell surface membrane structure is described as a 'fluid mosaic'. What correctly describes the 'mosaic' part of the cell surface membrane? A the different patterns that are…

A student immersed a plant tissue in solution S. For the next 30 minutes, the student used a microscope to observe the cells in the plant tissue. During this time, the cytoplasm…

Cell membranes become less fluid as the temperature decreases. Bacteria and yeast cannot regulate their cell temperatures. How do bacteria and yeast maintain the fluidity of their…

Samples X, Y and Z are epidermal tissues cut from an onion. Each epidermal tissue was immersed in one of three different concentrations of a salt solution for 30 minutes. A…

The graph shows the results of an osmosis investigation using potato tissue. The y-axis shows percentage change in mass (from −20 to +20) and the x-axis shows concentration of…

Some agar was coloured pink using a pH indicator. The pink agar was then used to make three agar cubes with different dimensions: 2 cm × 2 cm × 2 cm, 4 cm × 4 cm × 4 cm, and 5 cm…

Which components of the cell surface membrane can act as antigens? 1 glycoproteins 2 glycolipids 3 phospholipids A 1 and 2 B 1 and 3 C 2 and 3 D 1, 2 and 3

The diagram shows components of a cell surface membrane. X is a glycolipid and Y is a carrier protein. Which row correctly identifies X and Y? A X = carrier protein; Y =…

Antimycin is a drug that blocks the electron transport chain in mitochondria. Which processes would be directly affected by antimycin? A active transport and facilitated diffusion…

Visking tubing containing starch solution is placed into a solution of iodine. After 15 minutes, what would be observed? X = colour of iodine solution; Y = colour inside Visking…

Which substance can pass through the cell surface membrane without a protein? 1 glucose 2 CO₂ 3 Na⁺ ions A 1 only B 1 and 3 only C 1 and 2 only D 2 only

Which statement about facilitated diffusion is correct? 1 The rate is limited by the number of transport proteins. 2 It requires energy from ATP. 3 It can move molecules against a…

An enzyme is synthesised and secreted from a cell. What is the correct order of organelles involved? 1 cell surface membrane 2 Golgi body 3 rough endoplasmic reticulum 4 secretory…

The diagram shows apparatus used to investigate the movement of glucose molecules through a selectively permeable membrane (Visking tubing) at different initial concentrations (1%…

Fig. 1.1 shows a diagram of a root hair cell. Name the parts labelled X, Y and Z in Fig. 1.1.

Lysosomes are membrane-bound organelles found in mammalian cells. Scientists measured the concentration of cholesterol in the membranes of lysosomes in a mammalian cell. The…

Make a plan diagram of the midrib region of the leaf from slide N1. The midrib region is shown as the shaded area in Fig. 2.1. Label the cuticle on your plan diagram.

The diagram shows how nicotine is transported from the blood plasma into a cell using a type of cotransporter mechanism. A cotransporter protein spans the cell surface membrane.…

A student observed the effect of two different concentrations of salt solution on blood cells. The student added each concentration of salt solution to one of two microscope…

Which statement correctly describes facilitated diffusion?

Which process always takes place without the involvement of energy from ATP?

The diagram shows the entry of molecule X into a cell. Molecule X moves from outside the cell through a transport protein in the phospholipid bilayer into the cell. Which row…

The electron micrograph shows some human blood cells. Cell X is labelled - a red blood cell that appears shrunken with a crinkled (spiky) outline. Which row correctly shows the…

A red indicator solution was mixed with agar and the resulting solid was cut into small cylindrical blocks. The blocks were placed in an acid which turns the indicator yellow and…

What causes the phosphate heads of phospholipids to become polar? A The phosphate heads are joined to water molecules by hydrogen bonds. B The phosphate heads are insoluble in…

A red indicator solution was mixed with agar, and the resulting solid was cut into small cuboid blocks. The blocks were placed in an acid which turns the indicator yellow, and all…

The statements describe some events in the process of exocytosis of glycoprotein molecules. 1 Membrane of the Golgi body folds around glycoprotein molecules. 2 Vesicle binds to…

Four cylinders that were identical in size, A, B, C and D, were cut from potatoes that had been stored for different lengths of time. The cylinders were weighed, immersed in 10%…

Fig. 1.1 is a diagram showing part of a cell surface membrane of an animal cell. Fig. 1.1 shows a phospholipid bilayer with various components labelled A to F, and a line G-H…

Cyclin-dependent kinases (CDKs) are enzymes that regulate the cell cycle. Cell signalling by ligands causes the activation of CDKs in target cells. Outline the main stages in the…

Plasmolysis may be seen in onion cells that have been put into a sodium chloride solution. Plasmolysis occurs when water moves out of the cells and the cell surface membrane pulls…

The diagram shows part of a cell surface membrane drawn as a phospholipid bilayer. Structure 1 is a branched carbohydrate chain attached to a structure that projects from the…

The diagram shows the mean dimensions of an epithelial cell in micrometres (um), drawn as a rectangular box: width 2 um, height 3 um, length 8 um. Which row shows the surface area…

Which diagram shows the correct direction of net water movement between the four cells due to osmosis? Each diagram shows four cells arranged in a 2x2 block with arrows indicating…

An investigation was carried out into the effect of four different treatments on the permeability of the cell surface membranes and tonoplasts of beetroot cells. Beetroot cell…

A mixture of glucose and starch solutions was placed in a length of dialysis (Visking) tubing and the tubing sealed. The tubing was then placed in a boiling tube containing…

Which statements about phospholipids in cell surface membranes are correct? 1 Fatty acid tails allow most ions to pass through the membrane. 2 Hydrophobic tails point inwards…

In an experiment, pieces of onion epidermis are put into three different concentrations of sucrose solutions, P, Q and R. The pieces of onion are left for an hour and then…

The electron micrograph shows rod-shaped bacteria. The actual length of the bacterium is 2.0 um and the diameter is 0.5 um. Assume that the bacterium is cylinder-shaped. What is…

Before mitochondria are extracted from cells for microscopy, they are usually kept in a 0.25 mol/dm3 sucrose solution. Why is the sucrose solution used?

The photomicrograph shows a type of blood cell. The cells are numerous, rounded and biconcave with no nucleus (red blood cells). Which statements about these cells are correct? 1…

A student filled dialysis tubing with a sucrose solution and knotted both ends. This formed a cylinder with a length of 5.0 cm and a radius of 2.0 cm. What is the surface area to…

You will investigate the effect of different temperatures on the permeability of the cell surface membrane of beetroot cells. Beetroot contains a red pigment in its cells; when…

Which statement about cell signalling is correct? A One type of receptor molecule will recognise all ligands in the body. B The binding of a ligand may cause a change to the shape…

Four students, A, B, C and D, observed plant epidermal cells that had been placed in a concentrated sucrose solution for 30 minutes. They were asked to identify the partially…

The table compares the surface area to volume ratios of five agar blocks that differ in dimensions but which all have the same volume. The agar blocks can be used to measure the…

Which molecules in cell surface membranes are typically involved in cell recognition? The options are given as a table with a tick for 'involved' and a cross for 'not involved'…

What can increase the fluidity of the cell surface membrane? 1 single bonds between carbon atoms in the fatty acid chains; 2 cholesterol; 3 longer-chained fatty acids. A 1, 2 and…

The three main factors that affect the rate of diffusion across a membrane can be expressed by the relationship: rate of diffusion is proportional to (surface area x concentration…

A student measured the time taken for complete diffusion of a dye into agar blocks of different sizes which were suspended in the dye. The results are shown. size of agar block…

An experiment was carried out to investigate the effect of concentration of sucrose solution on cells in a plant tissue. A sample of plant tissue was cut into seven cylinders of…

Which row shows the distribution of cholesterol and the carbohydrate chains of glycolipids and glycoproteins in a cell surface membrane? A cholesterol between phospholipid heads…

Which row correctly describes all the possible relative concentrations of a substance when the substance is moved by endocytosis or exocytosis? A endocytosis = concentrations…

Which statement about simple diffusion is correct? A It requires specific molecules in the cell surface membrane. B It is a passive mode of transporting substances. C It always…

Plant cells with the same water potential in their cytoplasm were each put into one of three different concentrations of sugar solution, 10%, 5% and 2.5%. The cells were left for…

State why membrane proteins are required for the movement of molecules, such as glucose, across cell surface membranes into cells.

You will be investigating the effect of salt concentration on the movement of water in potatoes. You will need to make different concentrations of salt solution using proportional…

The diagrams show three types of covalent bonds. Bond 1 is an ester bond (C-O-C with a C=O), bond 2 is a glycosidic bond (C-O-C between two ring sugars), and bond 3 is a peptide…

Three individual plant leaf cells were each placed in a different solution for 30 minutes. Each solution had a different water potential. Which row correctly shows the change in…

Which component of cell surface membranes helps to reduce fluidity of the phospholipids at high temperatures? A phosphate groups B unsaturated fatty acids C cholesterol D proteins

Plant cells were left for 50 minutes in three different sugar solutions, 10%, 5% and 1%. The water potential in the cytoplasm of the three cells was the same at the start of the…

The diagram shows how adrenaline activates processes inside a cell. Adrenaline binds to a β-adrenergic receptor in the cell surface membrane, which activates a G protein that…

The statements are comparisons of endocytosis and exocytosis. • Both are mechanisms that involve vesicles or vacuoles and the transport of materials across the cell surface…

A student was asked to calculate the surface area : volume ratio for an agar cube with a side length of 5.5 mm. Which surface area : volume ratio is correct? A 0.2 : 1 B 0.9 : 1 C…

Scientists measured the concentration of sodium ions and potassium ions in the red blood cells and in the blood plasma of a group of people. The results are shown in Table 1.1.…

When potato cells are placed into different concentrations of sodium chloride solution, water moves between the solution and the potato cells. You will investigate the effect of…

Agar stained with universal indicator can be used to investigate diffusion; when hydrochloric acid diffuses into the agar it changes the colour from green to pink. You will…