Osmosis — Paper 2 · IGCSE Biology (9-1) 0970

8 Which part of a plant root hair is partially permeable? A the cell sap B the cell surface membrane C the cell vacuole D the cell wall

1 marks

Answer: B

This question in 0970/21 May/June 2018

6 The diagram shows a plant cell after it has been submerged in a solution, P, for 20 minutes. Which row describes the water potential of solution P and the condition of the cell? water potential of solution P condition of the cell A higher than the cell sap in the vacuole plasmolysed and turgid B higher than the cell sap in the vacuole under high turgor pressure C lower than the cell sap in the vacuole plasmolysed and flaccid D the same as the cell sap in the vacuole under low turgor pressure

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2018

7 The apparatus shown was set up. glass tube sugar solution pure water and blue ink partially permeable membrane Some hours later, the water in the beaker had turned blue, and the liquid in the glass tube had moved upwards. Which processes caused these changes? liquid in glass water turned tube moved blue upwards A osmosis diffusion B active transport osmosis C diffusion active transport D diffusion osmosis

1 marks

Answer: D

This question in 0970/21 May/June 2019

14 The cholera bacterium produces toxins that cause chloride ions to be secreted into the small intestine. How does this affect the water potential of blood in the intestinal capillaries and the intestinal contents? water potential blood in contents of capillaries small intestine A lowered lowered B lowered raised C raised lowered D raised raised

1 marks

Answer: C

This question in 0970/21 May/June 2019

7 Which process describes osmosis? A diffusion of water through a cell wall B diffusion of water through a partially permeable membrane C diffusion of water through the cell sap D diffusion of water through the cytoplasm

1 marks

Answer: B

This question in 0970/22 May/June 2019

14 The cholera bacterium produces toxins that cause chloride ions to be secreted into the small intestine. How does this affect the water potential of blood in the intestinal capillaries and the intestinal contents? water potential blood in contents of capillaries small intestine A lowered lowered B lowered raised C raised lowered D raised raised

1 marks

Answer: C

This question in 0970/22 May/June 2019

6 Red blood cells were placed in pure water. Movement of water across the cell membrane caused a change in their appearance. What caused this change in appearance? direction of from higher to lower from lower to higher water movement water potential water potential A into cells yes no B into cells no yes C out of cells yes no D out of cells no yes

1 marks

Answer: A

This question in 0970/22 Oct/Nov 2019

5 Which diagram shows the appearance of a plant cell several minutes after it has been placed in a concentrated solution of sugar? A B C D

1 marks

Answer: A

This question in 0970/21 May/June 2020

6 Plant cells are placed in a solution with a higher water potential than the plant cell contents. What will happen? direction of volume of water movement vacuole A enters cells decreases B enters cells increases C leaves cells decreases D leaves cells increases

1 marks

Answer: B

This question in 0970/21 May/June 2020

5 Which diagram shows the appearance of a plant cell several minutes after it has been placed in a concentrated solution of sugar? A B C D

1 marks

Answer: A

This question in 0970/22 May/June 2020

6 An uncooked piece of potato was placed in a solution. After two hours the size of the piece of potato had decreased. Which row explains why this has happened and how the potato cells have changed? water potential potato cells potato cells external solution become A higher lower flaccid B higher lower turgid C lower higher flaccid D lower higher turgid

1 marks

Answer: A

This question in 0970/22 May/June 2020

15 Which change increases the rate of water uptake by the roots of a plant? A decrease in evaporation of water from mesophyll cells B decrease in length of root hairs C decrease in water potential of root hair cells D decrease in water potential of soil water

1 marks

Answer: C

This question in 0970/22 May/June 2020

5 What are features of osmosis? requires a partially ousion . requires cell walls permeable membrane A v x Y B v x x Cc x v Y D x v x key /= yes X= no

1 marks

Answer: A

This question in 0970/22 Oct/Nov 2020

6 The diagram shows apparatus which can be used to demonstrate osmosis. 1 2 glass tube liquid level very concentrated concentrated water sucrose solution sucrose solution partially permeable membrane After one hour, what would happen to the liquid levels in the glass tubes? liquid level in liquid level in tube 1 tube 2 A falls falls B falls rises C rises falls D rises rises

1 marks

Answer: D

This question in 0970/22 Oct/Nov 2020

15 Statements 1 to 4 describe stages in the development of cholera. 1 Chloride ions are secreted into the gut. 2 Osmosis causes water to move into the gut. 3 The infected person becomes dehydrated. 4 Toxins are produced by the pathogenic bacteria. What is the correct sequence of the four stages? A 1  2  3  4 B 1  4  3  2 C 4  1  2  3 D 4  1  3  2

1 marks

Answer: C

This question in 0970/21 May/June 2021

16 The diagram shows a newly planted seedling and the same seedling a few hours after being planted. seedling when planted seedling a few hours after planting soil What is the correct explanation for the change in the appearance of the leaves? A Transpiration is faster than water uptake by root hairs so cells have become flaccid. B Transpiration is faster than water uptake by root hairs so cells have become turgid. C Transpiration is slower than water uptake by root hairs so cells have become flaccid. D Transpiration is slower than water uptake by root hairs so cells have become turgid.

1 marks

Answer: A

This question in 0970/22 Oct/Nov 2021

6 Plant tissue is placed in a solution. What would cause plasmolysis of the plant cells? 1 the external solution having a higher water potential than the plant cells 2 the external solution having a lower water potential than the plant cells 3 water moving out of the plant cells 4 water moving into the plant cells A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2022

13 The cholera bacterium produces toxins that cause chloride ions to be secreted into the small intestine. What is the immediate effect of this on the water potential of blood in the intestinal capillaries, and on the water potential of the contents of the small intestine? water potential blood in contents of capillaries small intestine A lowered lowered B lowered raised C raised lowered D raised raised

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2022

21 Which process could continue without energy from respiration? A active transport B growth C osmosis D protein synthesis

1 marks

Answer: C

This question in 0970/22 Oct/Nov 2022

5 The diagram shows an experiment demonstrating osmosis using a dialysis tubing bag. glass tube water sugar solution dialysis tubing bag After 30 minutes, the level of the liquid in the glass tube goes … 1 … because the water had a … 2 … water potential than the sugar solution. Which words correctly complete the statement? 1 2 A down lower B down higher C up lower D up higher

1 marks

Answer: D

This question in 0970/21 May/June 2023

19 The cholera bacterium toxin causes dehydration and loss of salts from the blood in humans. Which statement explains the reason for this? A Chloride ions are secreted into the small intestine where they increase the water potential. B Chloride ions are secreted into the small intestine which causes water to move into the intestine by osmosis. C Chloride ions are secreted into the small intestine which causes water to move out of the intestine by osmosis. D Chloride ions are secreted into the small intestine which causes the water potential of the blood to decrease.

1 marks

Answer: B

This question in 0970/21 May/June 2023

5 The diagram shows a root hair cell. When does water enter the cell by osmosis? A when the concentration of solutes outside the cell is greater than inside the cell B when the concentration of solutes inside and outside the cell are equal C when the water potential inside the cell is higher than outside the cell D when the water potential outside the cell is higher than inside the cell

1 marks

Answer: D

This question in 0970/22 May/June 2023

19 Cholera bacteria in the gut cause secretion of chloride ions which leads to diarrhoea. Which diagram shows the correct movement of chloride ions (Cl –) and water (H2O)? A B gut small intestine gut small intestine epithelial cell epithelial cell Cl – Cl – H2O H2O C D gut small intestine gut small intestine epithelial cell epithelial cell Cl – Cl – H2O H2O

1 marks

Answer: B

This question in 0970/22 May/June 2023

6 The diagram shows an experiment to investigate osmosis in living cells. water potato glass dish concentrated sugar solution What happens to the volumes of water and sugar solution after 12 hours? volume of volume of water sugar solution A decreases increases B increases increases C increases remains the same D remains the same decreases

1 marks

Answer: A

This question in 0970/22 Oct/Nov 2023

5 Samples of plant cells from the same species are immersed in three different liquids. The low concentration sucrose solution has a higher water potential than the plant cell cytoplasm. The high concentration sucrose solution has a lower water potential than the plant cell cytoplasm. What is the state of the cells in the different liquids? low concentration high concentration distilled water sucrose solution sucrose solution A turgid plasmolysed flaccid B flaccid turgid plasmolysed C flaccid plasmolysed flaccid D turgid turgid plasmolysed

1 marks

Answer: D

This question in 0970/21 May/June 2024

21 One of the symptoms of the disease cholera is diarrhoea. This is due to water loss by osmosis caused by the cholera toxin. What is the effect of cholera toxins that results in diarrhoea? A secretion of chloride ions out of the small intestine lowering the water potential B secretion of chloride ions out of the small intestine raising the water potential C secretion of chloride ions into the small intestine lowering the water potential D secretion of chloride ions into the small intestine raising the water potential

1 marks

Answer: C

This question in 0970/21 May/June 2024

7 The diagram shows the water potential of three plant cells. The more negative the value, the higher the solute concentration. P Q –360 kPa – 400 kPa –340 kPa R What is the immediate movement of water that will occur between the three cells? A from P to Q, and from R to P and Q B from Q to P and R only C from Q to P and R, and from P to R D from R to Q only

1 marks

Answer: A

This question in 0970/22 Oct/Nov 2024

7 Uncooked potato cylinders of identical size were placed in four different liquids for two hours. The different liquids are listed. 1 pure water 2 a sugar solution that was less concentrated than the contents of the potato cells 3 a sugar solution that was more concentrated than the contents of the potato cells 4 a sugar solution that was the same concentration as the contents of the potato cells In which liquids will the potato cylinders increase in length? A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: A

This question in 0970/22 May/June 2025