Bio grade 8 copy
Download as DOCX, PDF1 like844 views
This document provides instructions for a biology exam for grade 8 students. It consists of two sections, with Section A containing 40 multiple choice questions and Section B containing structured questions requiring short answers. The total marks for the exam are 100. The document outlines the instructions students must follow, including writing their answers in the provided spaces and fastening all work together at the end. It provides context for summarizing the content of the exam.
![7
37. For which food test must the sample be dissolved in ethanol?
A. Fat B. Protein C. reducing sugar D. Starch
38. What makes an organ?
A. Organelles B. cells C. tissues D. System
39. …………………….. are fatty acids
A. Proteins B. Lipids C. Fats D. nucleic acid
40. What is C6H12O6?
A. Alcohol B. glucose C. glycogen D. Enzyme
SECTION B
Answer all the questions from this section
1. The diagram below shows a cell seen under a microscope.
a) Name the structures labeled A, B and C. [3]
A……………………………. B …………………….. C…………………………..
b) Which of the structures would not be found in a human cheek cell?
…………………………………………………………………………………….……… [1]
c) What is the function of structure A?
…………………………………………………………………….……………………… [1]
d) What is the storage molecule of this cell?
……………………………………………………………………….……………..……. [1]
e) Which structure contains DNA?
…………………………………………………………………………………………… [1]
[Total: 7 marks]
A
B
C](https://image.slidesharecdn.com/biograde8-copy-150128084629-conversion-gate02/85/Bio-grade-8-copy-7-320.jpg)
![8
2. a)The diagram below shows the process of osmosis
i) Label the membrane with the letter C. [1m]
ii) State the region where the water potential is high. [1m]
……………………………………………………………………………….....................………………
iii) What is the meaning of semi-permeable membrane? [1m]
………………………………………………………………………………………………………………
……………………………………………………………………………..............................................
iv) On which way would be the net flow of water? [1m]
………………………………………………………………………………………………………………
……………………………………………………………………………...............................................
v) Define the term ‘osmosis’ [2m]
………………………………………………………………………………………………………………
……………………………………………………………………………...............................................
b)
i) Describe the water potential of the liquid. [2m]
………………………………………………………………………………………………………………
………………………………………………………………………………………………………………
………………………………………………………………………........................................................
RegionA RegionB
Key:
Water
Salt](https://image.slidesharecdn.com/biograde8-copy-150128084629-conversion-gate02/85/Bio-grade-8-copy-8-320.jpg)
![9
ii) Explain the effect of water potential of the liquid on the cells. [2m]
…………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………
………………………………………………….
[Total : 10 marks]
3. Figure 3.1 shows a plant cell and an animal cell.
b)Name the storage organelle found in animal cell and plant cell.
………………………………………………………………………………………….….......................[2m]
a) The storage molecules of these cells come under which type of biological molecule?
……………………………………………………………………………………....................….…[1m]
b) Name an animal cell which does not have a nucleus.
………………………………………………………………………………..…......................….…[1m]
c) In which part of the cell does chemical reaction takes place?
……………………………………………………………………………………......................…..[1m]
[Total: 8 marks]
Fig 3.1
Fig 3.1 draw and label](https://image.slidesharecdn.com/biograde8-copy-150128084629-conversion-gate02/85/Bio-grade-8-copy-9-320.jpg)
![10
4.
(b) i) By referring fig 4.1, explain why only a small amount of enzyme is needed to catalyst a
reaction involving many molecules.
...............................................................................................................................
...............................................................................................................................
c) Explain the ‘lock’ and ‘key’ hypothesis of the enzyme reaction.
……………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………
……………………………….................................................................................………………[4m]
[Total: 12 marks]
Fig 4.1 shows, in order, four stages in which an enzyme-controlled chemical reaction
may occur.
Fig4.1](https://image.slidesharecdn.com/biograde8-copy-150128084629-conversion-gate02/85/Bio-grade-8-copy-10-320.jpg)
![11
5. Write the name and functions of the following cells.
a)
b)
[Total:6marks]
6. All the diets contain protein for the synthesis of the cell.
a) What are the specific roles of protein inside the body?
………………………………………………………………………………………………………………
………………………………………………………………………………………………………………
………………………………………………………………………………………………………………
………………………………………………………………………………………………………………
………..........................................................................................................…………………[5m]
b) State the deficiency diseases of protein.
...................................................................................................................................................
................…………………………………………………………………….…………………[2m]
[Total: 7 marks]
7. Define the following:
a) Diffusion
…………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………
…………………………................................................................…………………………………[2m]
b) Multicellular organism
…………………………………………………………………………………………………………………
……………………………………………………….........................................……………………[1m]
Name:………………………………………
Function:……………………………………
………………………………………………
………………………………………………
………………………………………………
Name:………………………………………
Function:……………………………………
………………………………………………
………………………………………………
………………………………………………](https://image.slidesharecdn.com/biograde8-copy-150128084629-conversion-gate02/85/Bio-grade-8-copy-11-320.jpg)
![12
c) Catabolism
…………………………………………………………………………………………………………………
…………………..........................................………………………………………………………….[1m]
d) Respiration
…………………………………………………………………………………………………………………
…………………………………………………...........................................…………………………[1m]
[Total: 5 marks]
8. Answer any one of the following questions.
a) Explain how xylem vessels are adapted for their function.
Or
b) Define respiration and write the difference between aerobic and anaerobic respiration.
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
………………………………………………………………………………………………………………………
…………............................................................................................................................................……
[Total: 5 marks]
All the best](https://image.slidesharecdn.com/biograde8-copy-150128084629-conversion-gate02/85/Bio-grade-8-copy-12-320.jpg)
Bio grade 8 copy
- 1. 1 First TERM EXAMINATION- 2012 G. A. Atoll School, kolamaafushi Biology/Grade 8 2 hours 15 Mins Date: 17th may 2012 READ THESE INSTRUCTIONSFIRST Do not use staples, paper clips, highlighters, and glue or correction fluid. Write your name, class and index on the answer sheet in the spaces provided. Answer all the questions. Write your answers in the spaces provided on the Question Paper. This paper consists of two sections. The number of marks is given in bracket ( ) at the end of each question or part question. Total marks for this paper is 100. At the end of the examination, fasten all your work securely together. This document consists of 12 printed pages Name: Class: Index:
- 2. 2 Section A Choose the correct answer and circle the letter (40 marks) 1. A chemical molecule contains sulphur and phosphorous.Which of the following could it be? A A carbohydrate B. A fatty acid C. A protein D. Glycerol 2. Which processes moves sugar from leaf cells into phloem tissue? A. Active transport B. Osmosis C. Diffusion D. Photosynthesis 3. Respiration in living organisms always involves? A. Oxygen consumption C. Carbondioxide production B. Energy release D. Gaseous exchange 4. Which of the substances must be present in the soil for the growth of a healthy green plant? A. Glucose B. Amino acid C.CarbondioxideD. Magnesium 5. Which structures in a plant cell contain DNA and cellulose? DNA Cellulose A B C D Cell wall Chloroplast Cytoplasm Nucleus Cytoplasm Nucleus Chloroplast Cell wall 6. Some substances in living organisms move by active transport. Which line is correct for active transport? A. Movement of substances from low concentration to high concentration by using energy. B. Movement of substances from low concentration to high concentration without using energy. C. Movement of substances from low concentration to low concentration by using energy. D. Movement of substances from low concentration to low concentration without using energy 7.
- 3. 3 8.Starch is an example of : A. Monosaccharide B. Lipids C. Disaccharides D. Polysaccharides 9 A. Petals B. stem C. root D. flower 10. Starch is digested to maltose by the enzyme amylase. According to ‘lock’ and ‘key’ hypothesis, which is the ‘key’ and which is the ‘lock’? ‘key’ ‘lock’ A B C D Amylase Amylase Starch Starch Maltose Starch Amylase Maltose 11. A. Roots B. flowers C. leaves D. fruits 12. Which chemical change takes place in green plants but not in mammals? A. Glycogen into glucose C. Glucose into cellulose B. Starch into glucose D. Glucose into glycogen. 13. Which component of the diet prevents constipation? A. Fibre B.minerals C.protein D.vitamins 14. The sum of all chemical reactions that takes place in a living organisms is called…………………. A. Anabolism B. Metabolism C. Catabolism D. Respiration 15.What is the function of skeletal tissue? A. Sets up nerve impulses. B. Binds and strengthens around the body C. Supports and protects softer tissues and allows movement D. Lines tubes such as gut and covers surface such as skin 16. Some molecules change the likelihood of an enzyme being able to bind to its substrate. Which one of the following makes this binding more likely? A. Products B. Activators C. Inhibitors D. Proteins
- 4. 4 17. The diagram shows one type of a plant cell. What type of a cell is it? A. Epidermal cell of a leaf C. Root hair cell B. Mesophyll cell of a leaf D. Xylem cell 18. Which two structures are found only in plants? A. Cytoplasm and cell membrane C. Cell wall and sap vacuole B. Nucleus and sap vacuole D. Chloroplast and cell membrane 19.The diagram shows a plant cell as seen under a microscope. What are the functions of numbered parts? Control the entry of substances Synthesis of carbohydrates A B C D 1 2 3 3 3 1 2 1 20. Which of the following is the subunit of protein? A. Glucose B. Protein C. Glycerol D. Nucleotides 21. Which gas is released during respiration? A. Oxygen C. Hydrogen B. Nitrogen D. Carbondioxide 1 2 3
- 5. 5 22. The diagram shows five different cells as seen through amicroscope. Which one of the cells is a plant cell? A. 1 and 2 B. 2 and 5 C. 2 and 4 D.3 and 4 23. Which of the following process helps in the generation of new individuals? A. Reproduction B. Respiration C. Irritability D. Excretion 24. Which of the following is the sub-unit of nucleic acids? A. Amino acids B. Glycerol C. Nucleotides D. Fatty acids 25. 26. Which enzyme breaks hydrogen peroxide to water and oxygen? A. Lipase B. Protease C. Amylase D. Catalase 27.Which process releases the energy required for an organism? A. Reproduction B. RespirationC. Excretion D. Digestion 1 2 3 4 5 1 2 3 4
- 6. 6 28. Which of the following has both cytoplasm and cell wall? A. Blood cell B. Nerve cell C. Muscle cell D. Root hair cell 29 In the human body where is bile produced? A. Gall bladde B. Liver C. Pancreas D. Stomach 30. Which one of the following cells carries out the functions of nervous system? A. Blood cell B. Nerve cell C. Muscle cell D. Xylem cell 31. 32.Where in the alimentary canal is most water absorbed? A. colon B.ileum C.oesophagusD.stomach 33. Which food would be best for a person suffering from anaemia? 34. Milk produces a red precipitate when heated with Benedict’s solution. A purple colour develops when the biuret test is used on milk. Using these results only, which nutrients does milk contain? A.fat and protein B.fat and starch C.reducing sugar and protein D.reducing sugar and starch 35. What are some of the end products and effects of anaerobic respiration in muscle? A.carbon dioxide and muscle contraction C.lactic acid and oxygen debt B.ethanol and loss of coordination D.water and muscle relaxation 36.Which statement is not correct? A. Anaerobic respiration releases less energy than aerobic respiration B. The sun is the principle source of energy input into biological systems C. Energy flowing through biological systems is recycled D. Active transport is an energy consuming process
- 7. 7 37. For which food test must the sample be dissolved in ethanol? A. Fat B. Protein C. reducing sugar D. Starch 38. What makes an organ? A. Organelles B. cells C. tissues D. System 39. …………………….. are fatty acids A. Proteins B. Lipids C. Fats D. nucleic acid 40. What is C6H12O6? A. Alcohol B. glucose C. glycogen D. Enzyme SECTION B Answer all the questions from this section 1. The diagram below shows a cell seen under a microscope. a) Name the structures labeled A, B and C. [3] A……………………………. B …………………….. C………………………….. b) Which of the structures would not be found in a human cheek cell? …………………………………………………………………………………….……… [1] c) What is the function of structure A? …………………………………………………………………….……………………… [1] d) What is the storage molecule of this cell? ……………………………………………………………………….……………..……. [1] e) Which structure contains DNA? …………………………………………………………………………………………… [1] [Total: 7 marks] A B C
- 8. 8 2. a)The diagram below shows the process of osmosis i) Label the membrane with the letter C. [1m] ii) State the region where the water potential is high. [1m] ……………………………………………………………………………….....................……………… iii) What is the meaning of semi-permeable membrane? [1m] ……………………………………………………………………………………………………………… …………………………………………………………………………….............................................. iv) On which way would be the net flow of water? [1m] ……………………………………………………………………………………………………………… ……………………………………………………………………………............................................... v) Define the term ‘osmosis’ [2m] ……………………………………………………………………………………………………………… ……………………………………………………………………………............................................... b) i) Describe the water potential of the liquid. [2m] ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… ………………………………………………………………………........................................................ RegionA RegionB Key: Water Salt
- 9. 9 ii) Explain the effect of water potential of the liquid on the cells. [2m] ………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………… …………………………………………………. [Total : 10 marks] 3. Figure 3.1 shows a plant cell and an animal cell. b)Name the storage organelle found in animal cell and plant cell. ………………………………………………………………………………………….….......................[2m] a) The storage molecules of these cells come under which type of biological molecule? ……………………………………………………………………………………....................….…[1m] b) Name an animal cell which does not have a nucleus. ………………………………………………………………………………..…......................….…[1m] c) In which part of the cell does chemical reaction takes place? ……………………………………………………………………………………......................…..[1m] [Total: 8 marks] Fig 3.1 Fig 3.1 draw and label
- 10. 10 4. (b) i) By referring fig 4.1, explain why only a small amount of enzyme is needed to catalyst a reaction involving many molecules. ............................................................................................................................... ............................................................................................................................... c) Explain the ‘lock’ and ‘key’ hypothesis of the enzyme reaction. …………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… ……………………………….................................................................................………………[4m] [Total: 12 marks] Fig 4.1 shows, in order, four stages in which an enzyme-controlled chemical reaction may occur. Fig4.1
- 11. 11 5. Write the name and functions of the following cells. a) b) [Total:6marks] 6. All the diets contain protein for the synthesis of the cell. a) What are the specific roles of protein inside the body? ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… ………..........................................................................................................…………………[5m] b) State the deficiency diseases of protein. ................................................................................................................................................... ................…………………………………………………………………….…………………[2m] [Total: 7 marks] 7. Define the following: a) Diffusion ………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………… …………………………................................................................…………………………………[2m] b) Multicellular organism ………………………………………………………………………………………………………………… ……………………………………………………….........................................……………………[1m] Name:……………………………………… Function:…………………………………… ……………………………………………… ……………………………………………… ……………………………………………… Name:……………………………………… Function:…………………………………… ……………………………………………… ……………………………………………… ………………………………………………
- 12. 12 c) Catabolism ………………………………………………………………………………………………………………… …………………..........................................………………………………………………………….[1m] d) Respiration ………………………………………………………………………………………………………………… …………………………………………………...........................................…………………………[1m] [Total: 5 marks] 8. Answer any one of the following questions. a) Explain how xylem vessels are adapted for their function. Or b) Define respiration and write the difference between aerobic and anaerobic respiration. ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………… …………............................................................................................................................................…… [Total: 5 marks] All the best