MODEL PAPER OF SSC PUBLIC EXAMINATION FOR THE ACADEMIC YEAR 2025-2026 BY THE DIRECTOR OF GOVT.EXAMINATIONS (SSC BOARD), A.P

 

MODEL PAPER 1 BY DGE

2025 - 26 GENERAL SCIENCE -PAPER-II

BIOLOGICAL SCIENCE (ENGLISH VERSION)

 Time : 2 Hours  Max. Marks : 50

 

SECTION - I (6 x 1 = 6 Marks)

1.    Write a slogan to create awareness about organ donation among the people.

Answer: Give the gift of life, become an organ donor. (or) Don't wait for a miracle, be someone's miracle.

 

2.    Identify the part 'X' labelled in the following diagram.

 

Answer: Stomatal pore

 

3.    Would you recommend vegetative propagation for growing fruit plants? Give reason.

Answer: Yes, vegetative propagation is good for growing fruit plants because it gives same quality fruits as the parent plant and helps in faster growth and early fruiting.

 

4.    Identify the animal which show regeneration

A) Yeast B) Hydra C) Amoeba D) Leishmania

Answer: B) Hydra.

 

5.    Name two animals in which sex is not genetically determined.

Answer: Turtles (sex determined by the temperature of the environment) and Clownfish (sex can change based on social dynamics).

 

6.    Who proposed the laws of inheritance?

Answer: Gregor Mendel.

 

SECTION - II (4 x 2 = 8 Marks)

7.    What is synapse? Write its importance?

Answer: A synapse is a small gap between two nerve cells where messages pass through.
It helps one neuron send signals to another.
It is important for communication within the nervous system.

 

8. What precautions do you follow to escape from the dental caries?

Answer: Precautions to prevent dental caries (tooth decay) include:

Brushing teeth twice a day using a fluoride toothpaste and flossing once a day.

Reducing the frequency of eating sugary foods and drinks, especially avoiding sugary snacks between meals.

 

9.    Which organisms represents the producer and herbivore in the given food chain

Answer:

·         Producer: Grass (first organism)

·         Herbivore: Grasshopper (second organism)

The grass makes its own food (producer), and the grasshopper eats the grass (herbivore).

 

10.           How is the amount of urine produced regulated?

The amount of urine produced is regulated by:

       I.            The amount of water and salts in the body.

    II.            A hormone called ADH (Antidiuretic Hormone) which controls water reabsorption in kidneys.

 III.            When the body needs more water, less urine is produced; when there is excess water, more urine is produced.

 

SECTION - III (5 x 4 = 20 Marks)

11.           Compare the alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.

Alveoli (Lungs)	Nephrons (Kidneys)
Tiny air sacs with capillaries.	Microscopic filters (glomerulus and tubules).
Function: Gas exchange (O2 in, CO2 out).	Function: Filtration of blood to form urine.
Oxygen diffuses into blood, CO2 out.	Blood is filtered, waste forms urine.
Large surface area for diffusion.	Coiled tubules for absorption and secretion.
Surrounded by capillaries for exchange.	Surrounded by capillaries for reabsorption.

 

12.           Draw a neat labelled diagram of the following. A) Nerve Cell (OR) B) Excretory system in human

 

13.           How Can you help in reducing the problem of waste disposal? Give any two methods.

Reduce Usage: Minimize the use of plastic and other non-biodegradable materials.

Recycle and Reuse: Encourage recycling and reusing items like plastic, glass, and metal.

Proper Disposal: Dispose of non-biodegradable waste in designated recycling centers.

Promote Alternatives: Use biodegradable and eco-friendly products​

 

14.           Write a short note about contraceptive methods.

I. Barrier Methods
• Stop sperm from reaching the egg
• Examples: Male condom, female condom, diaphragm

II. Hormonal Methods
• Use hormones to stop ovulation or block sperm
• Examples: Oral pills, patches, vaginal rings

III. Intrauterine Devices (IUDs)
• Small devices placed in the uterus
• Prevent pregnancy by stopping fertilization or implantation
• Examples: Copper IUD, hormonal IUD

IV. Surgical / Permanent Methods
• Permanently stop the release of sperm or eggs
• Examples: Vasectomy (male), tubal ligation (female)

 

15.           What happens if predators are removed from an ecosystem? How it influences the organisms in the other trophic levels?

If predators are removed from an ecosystem:

       I.            The population of prey (herbivores) increases rapidly.

    II.            Overgrazing or overfeeding by herbivores reduces plant (producer) numbers.

 III.            Lack of balance causes food shortage for herbivores later.

IV.            The entire food chain becomes unstable, affecting all trophic levels.

SECTION - IV (2 x 8 = 16 Marks)

 

16.                       A) Write the experimental procedure that you follow in your lab to prove the action of saliva on starch.

 

Aim: To prove the action of saliva on starch

Apparatus:

• 2 test tubes
• Starch solution
• Saliva
• Iodine solution                 

Procedure:

1.    Take 2 test tubes

2.    Add 1 ml of starch solution to each test tube.

3.    Label them A and B.

4.    Add 1 ml of saliva to test tube A.

5.    After 30 minutes, add iodine solution to test tube A and B

Observation:

• Test Tube A: No color change (indicating no starch).
• Test Tube B: Turns blue-black (indicating starch presence).

Result: Proved the action of saliva on starch

 

(OR) B) Explain an activity to observe reproduction in yeast.

 

Aim

To observe yeast cells and their budding under a microscope.

 

Materials

Sugar, water, yeast, test tube, cotton plug, glass slide, coverslip, microscope.

 

Procedure

·       Make sugar solution

·       Pour into test tube

·       Add yeast (a pinch)

·       Keep warm place

·       Observe under microscope

Observation

Oval-shaped yeast cells are seen. Some cells show small outgrowths called buds.

 

Result

Yeast reproduces by budding.

 

 

17.           A) How does phototropism occurs in plants?

Aim: Demonstrate plant growth towards light.
 Apparatus: Flask, water, wire mesh, germinating seeds, cardboard box.

Procedure: Place germinating seeds on wire mesh over a water-filled flask.
 Keep setup in a box with one open side facing light.

 Observation: Shoots bend towards light (positive phototropism).
 Reversing plant orientation still shows light ward growth.
 Conclusion: Light influences shoot growth direction.

 

(OR) B) How do Mendel's experiments show that traits may dominant or recessive?

·         Selection of Pea Plants:
Mendel used pea plants with contrasting traits (e.g., tall vs. dwarf plants) for his experiments.

·         Cross-Pollination:
He crossed pure-breeding tall plants (TT) with pure-breeding dwarf plants (tt).

·         F1 Generation:
All offspring (F1) were tall. Mendel concluded that the tall trait is dominant, and the dwarf trait is recessive.

	T	T
t	Tt	Tt
t	Tt	Tt

·         Self-Pollination of F1:
He allowed the F1 tall plants (Tt) to self-pollinate.

·         F2 Generation:

	T	t
T	TT	Tt
t	Tt	tt

The F2 generation showed

Phenotypic ration is 3:1 (Tall : Short)

Genotypic Ratio is 1:2:1 (TT : Tt : tt).

 

Conclusion:

• Each plant has two factors (now called alleles) for a trait.
• The dominant allele (T) masks the recessive allele (t) in hybrids. (Law of Dominance )
• Traits segregate independently during reproduction. (Law of segregation )