Integrated Science DIFFUSION, OSMOSIS & PLASMOLYSIS

This SHS Integrated Science Revision Notes covers DIFFUSION, OSMOSIS, AND PLASMOLYSIS. It is aimed at helping students to have a quick revision of what they have studied.

SHS Integrated Science Revision: DIFFUSION, OSMOSIS, AND PLASMOLYSIS

1. The movement of both organic and inorganic substances from one part of the body to another is known as….. Transport of substances.

2. Common substances that are transported in organisms are …. Oxygen, carbon dioxide, water, urea, salts, hormones and food materials.

3. The two main transport systems in humans are the blood circulatory system and the…… Lymphatic system

4. The two transport systems in plants are xylem tissues and the ……….phloem tissues.

5. The blood circulatory system consists of the…… heart, blood vessels, and the blood.

6. Which system carries materials around the body in humans…….. Lymphatic system

7. Give four importance of the transport system in living organisms

– it connects different parts of the body together

– it helps in the distribution of water to various parts of the body

– it helps in transporting oxygen to all parts of the organism

– it helps in transporting waste materials from different parts of the body to excretory organs.

– it helps in transporting raw materials to food synthesizing tissues.

8. Which structure in the cell allows movement of certain substances (particles) in and out of the cell…….. cell membrane

9. Substances (particles) enter the cell by three means namely…. Diffusion, osmosis, and active transport.

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SHS Integrated Science Revision Notes: DIFFUSION, OSMOSIS, AND PLASMOLYSIS

10. the movement of molecules from a region of higher molecular concentration to a region of lower concentration of molecules though a permeable membrane is known as… Diffusion.

11. The movement of water (solvent) molecules across a semi-permeable membrane from a dilute solution to (higher concentration of water) to a more concentrated solution (lower concentration of water) is known as…… Osmosis

12. The movement of dissolved substances from a region where they are in low concentration to a region where the dissolved substances are in higher concentration using energy from the cell is known as….. Active transport.

13.Diffusion occurs as a result of …… difference in concentration molecules between the two regions

14. The difference in concentration of molecules between the two regions is known as …. Concentration gradient

15. Diffusion ceases when the concentration gradient between the two adjourning regions becomes the….same

16. Give four examples of diffusion in living things

– diffusion of oxygen into the blood and carbon dioxide out of the blood into the lungs of mammals.

– diffusion of carbon dioxide into the leaf and oxygen out of the leaf through the stomata

– absorption of end products of digestion in the small intestine of mammals.

– diffusion of hormones out of the endocrine glands

– Diffusion of mineral salts from the soil water into root hair cell

– transpiration of water from the stomata of plants is an example of diffusion.

17. Explain why diffusion is slower in gases than in liquids…….this because liquid molecules are closer together than gas molecules and hence move slowly.

18. Diffusion does not take place between two solids because …..their particles are closely packed and they vibrate at static positions.

19. Give four importance of diffusion ……

– it helps in transporting materials within the cell

– it helps in the absorption of nutrients and water

– it enables us to detect and smell the scent of objects/things

– it helps in the movement of oxygen into the blood and carbon dioxide leaving the blood.

20. Semi-permeable membrane may be a living or nonliving……..thing

SHS Integrated Science Revision Notes: DIFFUSION, OSMOSIS, AND PLASMOLYSIS

21. Give four examples of living semi-permeable membrane….peel yam, peeled cocoyam, the skin of the frog, the skin of a lizard

22. Give four examples of living non-living semi-permeable membrane……cellophane paper,

23. Show an experiment to demonstrate how diffusion occurs in liquid:

– fill a test tube or glass jar with water

– drop a few crystals of potassium permanganate into the water.

– it would be observed that the violet colour of potassium permanganate will in no time spread throughout the water until a uniform solution is obtained.

Molecules of potassium permanganate have spread (diffused) throughout the liquid. The molecules moved from an area of higher concentration to that of lower concentration.

SHS Integrated Science Revision Notes: DIFFUSION, OSMOSIS, AND PLASMOLYSIS

24. Diffusion do take place in liquids, solids, and …..gases

25. Give four examples of osmosis in living things:

– Absorption of water from the soil by roots of plants

– Absorption of water in the large intestine of mammals

– Absorption of water in the nephron of kidneys of mammals

– water enters the red blood cells to reduce the concentration of blood plasma or leaves the red blood cells to increase the concentration of blood plasma by osmosis.

25. Osmosis does not take place in ….. gases

26. Give four (4) uses of osmosis

– it helps plants to absorb and transport water from the soil into the root

– it helps in the turgidity of cells

– it helps in the absorption of water by living cells

– cells undergo plasmolysis through osmosis

– it helps in the movement of water from cell to cell within a plant

27. Define the following:

Hypotonic solution: It is a solution whose concentration is lower than the one it is being compared with.

Isotonic solution: it is a solution whose concentration is the same as the one it is being compared with.

Hypertonic solution: it is a solution whose concentration is higher than the one it is being compared with.

28. Give two (2) roles (examples) of osmosis in plants

– Absorption of soil water by root hair cells

– Movement of water from cell to cell within a plant.

29. Give two (2) roes ( examples) of osmosis in animals.

Entering of water into the cytoplasm of amoeba

The osmoregulatory function of the contractile vacuole in a unicellular organism.

Re-absorption of water in the kidney tubules of mammals.

30. The process by which a plant or animal cell loose water by osmosis as a result of the cell being placed or surrounded by a solution of higher concentration than the cell sap so that it eventually collapses as a result of losing water is known as… plasmolysis

31. What occurs when plants lose water to the atmosphere faster than they can obtain from the soil….. Flaccidity.

32. Tabulate three (3) differences between diffusion and osmosis

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Diffusion Osmosis Molecules/ particles move from a higher concentration region to a lower concentration region Molecules/particles move from a lower concentration region to a higher concentration region No semi-permeable membrane is involved A semi-permeable membrane is involved It takes place in liquids, gases, and in solids It takes place in liquids only It involves the movement of only solvent particles It involves movement of any particles including both solvent and solute particles.