SSC PUBLIC EXAMINATION (2025-26)
MODEL PAPER-3 (SCERT 100 days action plan)
BIOLOGICAL SCIENCE CLASS: X Time: 2 Hours
SECTION – I 1 mark. 6 × 1 = 6 M
1. Expand DNA.
• Deoxyribonucleic Acid
2. Identify the part 'A' labelled in
the following diagram.
• Bud
3. Write an example for sexually
transmitted diseases (STDs) caused by bacteria.
• Gonorrhoea
4. The gap between two neurons is
called a [ ]
a) Dendrite b) Synapse c) Axon d) Impulse
• b) Synapse
5. Write a slogan on female foelicide
to create awareness among the pupil.
• Save girl child, save the nation.
6. "Rate of breathing in aquatic
organisms is much faster than that of in terrestrial organisms". support
this statement.
• Because water has less dissolved oxygen than air.
SECTION – II 2 marks. 4 x 2 = 8 M
7. What will happen if these are no
decomposers in an ecosystem.
• Dead plants and animals accumulate.
• Nutrient recycling stops, ecosystem gets disturbed.
8. Read the following table and answer
the questions given.
|
S.No. |
Digestive glands |
Enzymes |
Acts on |
|
1 |
Salivary glands |
Salivary amylase |
Carbohydrates |
|
2 |
Gastric glands |
Pepsin |
Proteins |
|
3 |
Liver |
No enzyme |
Fats |
|
4 |
Pancreas |
Trypsin, Lipase |
Proteins, Fats |
a) Name the digestive gland seeretion,
that has no enzymes.
• Bile
b) Which enzymes acts on proteins ?
• Pepsin
• Trypsin
9. Write precautions to limit the
ozone depletion ?
• Avoid use of CFCs and harmful aerosols.
• Use eco-friendly products and reduce pollution.
10. Write the function of the
following hormones?
A) Insulin
• Controls blood sugar level.
• Helps cells use glucose.
B) Adrenalin
• Prepares body for emergency (fight or flight).
• Increases heart rate and blood pressure.
SECTION – III 4 marks 5 X 4 = 20 M
11. How are the alveoli designed to
maximise the exchange of gases.
• Alveoli have a large surface area.
• Walls are very thin and moist.
• Surrounded by dense network of blood capillaries.
• Gases diffuse quickly and efficiently.
12.a) Draw and label the diagram of structural and functional unit of
nervous system.
Structural and functional unit is Neuron.
(Or)
b) Draw the neat labelled diagram of process of fertilization in a flower.
13. Suggest any 4 environmental
friendly practices to reduce plastic waste.
• Use cloth or jute bags.
• Avoid single-use plastics.
• Reuse plastic items carefully.
• Send plastic waste for recycling.
14. How do plants respond to stimuli.
Justify the statement with suitable example.
• Plants respond through growth
movements.
• Response is due to plant hormones.
• Example: Phototropism in shoots.
• Shoot bends towards light.
15. Write any 4 slogans on waste
management ?
• Reduce waste, save Earth.
• Segregate waste at source.
• Recycle today for a better tomorrow.
• Clean environment, healthy life.
SECTION – IV 2 × 8 = 16 M
16.a) How do you demonstrate that the amount of carbon
dioxide is more in air that we breathe out than we breathe in ?
Aim: Demonstrate that the amount of carbon dioxide is more in air
that we breathe out (Exhaled Air) than
we breathe in
Apparatus:
- 2 test tubes
- Lime water
- Syringe
- Rubber tube
Procedure
1.
Take
2 test tubes
2.
Lable
as A & B
3.
Add
lime water to A & B
4.
Pass
air with syringe into A
5.
Blow
exhaled air into B
Observation
Lime water in test tube (B) turns milky faster
than in test tube (A).
Result: Exhaled air contains more carbon dioxide than we breathe in.
(Or)
b) Describe the procedure you followed in your school laboratory to observe the
spores in Breadmould.(Rhizopus.)
Aim: To observe the spores in Breadmould.
Materials:
·
Moist
bread slice
·
Petri
dish / clean container
·
Magnifying
glass
·
microscope
Procedure :
1. Take a bread slice
2. Make it moist.
3. Keep it in a cool, dark place.
4. Leave it for three days.
5.
Observe the bread under a magnifying glass.
6. For spores observe it under a
microscope.
Observation:
· A white cotton-like mass of mold
appears on the bread.
· After some time, these white threads
develop black, round sporangia.
Result : Observed the spores in Breadmould
17.a) Analyse the dihybrid cross with the help of a checker board.(How do Mendel's experiments show that traits are
inherited independently?)
i. Mendel crossed round green (RRyy)
with wrinkled yellow (rrYY) seeds.
ii. F1 generation had yellow round
seeds (dominant traits).
iii. In the F2 generation, the seeds
were in a 9:3:3:1 ratio of different traits.
9 Round Yellow
3 Round Green
3 Wrinkled Yellow
1 Wrinkled Green
iv. This showed that traits are
inherited independently of each other.
(or)
b) What are the differences between Stimulus and Response ?
|
Stimulus |
Response |
|
Change in the internal or external environment |
Action to stimulus (Body reaction) |
|
May be light, heat, touch |
Movement or secretion |
|
Starts activity |
Comes after stimulus |
|
Acts as an input |
Acts as an outcome |
|
Detected by receptors |
Executed by effectors |
|
carried by sensory nerves |
carried by motor nerves |
|
Example: touching hot object |
Example: withdraw hand from hot object |