Self Assessment Model Paper-1 (2025-26) – Answers
1. Identify the microorganism which causes dysentery and malaria.
A) Protozoa ✔
B) Bacteria
C) Algae
D) Fungi
2. Which of the following statements about antibiotics is TRUE?
A) Antibiotics are produced from plants and minerals.
B) They may disturb the gut environment by killing useful bacteria. ✔
C) Antibiotics are antiviral medications used to treat viral infections.
D) It is safe to share antibiotics with others if they have similar symptoms.
3. Which of the following diseases are caused by viruses?
1 - Measles
2 - Tuberculosis
3 - Chickenpox
4 - Cholera
A) 1 and 2 only
B) 2 and 3 only
C) 1 and 3 only ✔
D) 2 and 4 only
4. Identify the microorganism that grow on moist bread and spoil it.
A) Bacteria
B) Protozoa
C) Algae
D) Fungi ✔
5. Raveena is making a cake.
Which ingredient should she use to make the cake more fluffy?
A) Bacteria
B) Yeast ✔
C) Fungus
D) Lactobacillus
6. Which of the following options is a correct match in connection with the plant disease and causative microorganism?
P: Rust of wheat – Bacteria
Q: Yellow vein mosaic of bhindi – Virus
R: Citrus canker – Fungi
A) P only
B) Q only ✔
C) R only
D) both Q and R
7. Identify the suitable titles for Group A and Group B, respectively.
A) Viral diseases, Bacterial diseases
B) Human diseases, Animal diseases
C) Communicable diseases, non-communicable diseases ✔
D) Water born diseases, Air born diseases
8. Choose the correct answer based on the given assertion and reason
Assertion (A): Vaccines are made from dead or weakened microbes.
Reason (R): Vaccines directly kill pathogens in the body.
A) A is true but R is false ✔
B) A is false but R is true
C) Both A and R are true. R is the correct explanation of A
D) Both A and R are true. R is not the correct explanation of A
9. In which of these test tubes does the balloon inflate more?
A) A
B) B
C) C ✔
D) D
10. A student observes tiny, moving organisms in a drop of pond water under a microscope.
A) Bacteria and Virus
B) Protozoa and Algae ✔
C) Algae and Fungi
D) Virus and Fungi
11. Whose statement is correct?
A) Vennela
B) Suhana ✔
C) Rajesh
D) Praveen
12. Should the chemical that kills all microbes be used as a food preservative?
A) Yes
B) No, because chemicals make the food taste less
C) Yes, because it sterilizes food
D) No, because it may be harmful to humans ✔
13. Identify the carrier of dengue virus.
A) female Anopheles mosquito
B) male Anopheles mosquito
C) female Aedes mosquito ✔
D) male Aedes mosquito
14. Which combination of preservation methods would be most effective?
A) High sugar, airtight packing ✔
B) Boiling, then wrapping in silver foil
C) Salting then sealed with water
D) Cleaning and packing in polythene bag
15. What is the most logical reason for bad smell in cooked rice after two days?
A) Rice dried out
B) Oxygen removed
C) Steel reacted with rice
D) High moisture and warmth allow bacteria to multiply ✔
Section B 2 X 2 = 4
16. Name the scientists associated with the following.
i) Vaccine for smallpox
Edward Jenner
ii) Fermentation
Louis Pasteur
17. Explain why leguminous plants can grow in soil deficient in nitrogen.
Leguminous plants have Rhizobium bacteria in their root nodules.
These bacteria fix atmospheric nitrogen and convert it into usable nitrogen compounds.
Therefore, these plants can grow even in nitrogen-deficient soil.
Section C 2 x 4 = 8
18. Mention any four situations where you use microorganisms in day-to-day life.
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Preparation of curd using Lactobacillus.
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Baking bread and cakes using yeast.
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Production of alcohol and vinegar by fermentation.
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Decomposition of waste to form manure by microbes.
19. Draw a clear diagram of any one protozoan organism and label its name.
Example: Amoeba
Labels:
-
Pseudopodia
-
Nucleus
-
Cytoplasm
-
Cell membrane
-
Food vacuole
Section D 1 x 8 = 8
20 (A)Design a scientific activity to investigate and demonstrate which materials in a mixed sample of waste are biodegradable and which are non-biodegradable.
Aim:
To identify biodegradable and non-biodegradable materials.
Materials:
Two pots, soil, plant waste, plastic items, glass pieces.
Procedure:
-
Take two pots and fill them with soil.
-
Put plant waste in pot A.
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Put plastic and glass items in pot B.
-
Leave the pots for 3–4 weeks.
-
Observe the changes.
Observation:
Plant waste decomposes and forms manure in pot A.
Plastic and glass remain unchanged in pot B.
Conclusion:
Plant waste is biodegradable and plastic/glass are non-biodegradable.
20 (B) Cholera outbreak : A significant number of people in a village are experiencing stomach aches and watery stools. Doctors have confirmed that this is due to cholera outbreak.
i) Causative microorganism
Bacteria (Vibrio cholerae)
ii) Mode of transmission
Contaminated food and water
iii) Four preventive measures
-
Drink boiled or purified water
-
Maintain personal hygiene
-
Eat properly cooked food
-
Proper sanitation and waste disposal
iv) Another disease from same group
Typhoid
v) Mode of transmission
Contaminated water and food