CBSE - X
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CBSE X Time allowed: 3 hours; Maximum Marks: 100 |
| General Instructions: | |
| 1) | The question paper comprises of two sections A and B. You are to attempt both sections. |
| 2) | You are advised to attempt all the questions of Section A and Section B separately. |
| 3) | All questions are compulsory. |
| 4) | There is no overall choice. However, internal choice has been provided in some questions. You are to attempt only one option in such questions. |
| 5) | Marks allocated to every question are indicated against it. |
| 6) | Questions number 1-4 in Section A and 17, 18 in Section B are very short answer questions. These are to be answered in one word or one sentence. |
| 7) | Questions number 5-8 in Section A and 19, 20 in Section B are short answer questions. These are to be answered in 30 - 40 words each. |
| 8) | Questions number 9-14 in Section A and 21 - 23 in Section B are also short answer questions.These are to be answered in 40 - 50 words each. |
| 9) | Questions number 15, 16 in Section A and 24 in Section B are long answer questions. These are to be answered in 70 words each. |
Question 17
17. Name the term for transport of food from leaves to other parts of the plant.
Question 18
18. What is a neuron?
Question 19
19. Describe the mechanism of blood clotting.
Blood clotting is the mechanism that prevents the loss of blood at the site of injury or wound forming a ‘blood clot’. Blood has platelet cells that circulate around the body and plug these leaks by helping to clot the blood at these points of injury to prevent it from excessive bleeding.
The major events in blood clotting are as follows:
Injured tissue + Blood platelets →Release thromboplastin
Prothrombin (Inactive) →(Thromboplastin +Ca++ → Thrombin (Active)
Fribrinogen (Soluble) →Thrombin +Ca++ →Fibrin (Insoluble) (gel form)
Fibrin + Red blood corpuscles → Blood clot
Unless the blood clots at the site of injury, there will be loss of blood (blood hemorrhage).Such a loss of blood will lead to death of the person.
Or
State the two vital functions of the human kidney. Name the procedure used in the working of artificial kidney.
Question 20
20. Name the two hormones secreted by pancreas.Write one function of each hormone named
Question 21
21. (a) What is fertilization? Distinguish between external fertilization and internal fertilization.
(b) What is the site of fertilization in human beings?
Question 22
22. Define the terms :
(i) Analogous organs
(ii) Vestigial organ
(iii) Sex chromosome
Or
(a) What is ‘environmental pollution’?
(b) Distinguish between biodegradable and non-biodegradable pollutants.
(c) Choose the biodegradable pollutants from the list given below:
Sewage, DDT, radioactive waste, agricultural waste
Question 23
23. Suggest three ways to maintain a balance between environment and development to survive.
Question 24
24. (a)Draw a diagram of a ‘palisade cell’.
(b) Label vacuole, chloroplast, cell wall and cytoplasm on the diagram drawn.
(c) Name the two stages in photosynthesis.
| Section A |