ICSE Class 6 Biology Sample Paper with Solutions Set 01

ICSE Board
Class VI Biology
Sample Paper - 1

Time: 2 hrs                                                                                                   Total Marks: 75

General Instructions:
1. All questions are compulsory.
2. Questions 1 to 15 carry one mark each.
3. Questions in 2 A and B carry one mark each.
4. Questions in 3 A carry one mark each and B carries 5 marks.
5. Question 4 A and B carries 5 marks each.
6. Questions in 5 A and B carry one mark each.
7. Questions in 6A and B carry one mark each.
8. Question 7 A and B carry five marks each.

Question 1

Choose the correct answer out of the four available choices given below each question. [15]

1. Who coined the term 'cell'? [1 Mark]
(a) Matthias Schleiden
(b) Theodor Schwann
(c) Charles Darwin
(d) Robert Hooke

Answer: (d) Robert Hooke

Robert Hooke coined the term cell in 1665 after examining a thin section of cork under a microscope.

Teacher's Note:
a) Robert Hooke observed empty box-like compartments in cork and named them cells.
b) Students must remember that Hooke observed dead plant tissue (cork), not living cells.

2. Which of the following connects the pharynx to the stomach? [1 Mark]
(a) Large intestine
(b) Oesophagus
(c) Caecum
(d) Small intestine

Answer: (b) Oesophagus

Oesophagus or the food pipe is a muscular tube which connects the pharynx to the stomach.

Teacher's Note:
a) The oesophagus uses peristaltic movements to push food down into the stomach.
b) Do not confuse the trachea (windpipe) which lies in front of the oesophagus.

3. Transpiration is a function of the _____________. [1 Mark]
(a) Leaves
(b) Stem
(c) Flower
(d) All of these

Answer: (a) Leaves

Leaves bear numerous microscopic pores called stomata through which excess water is lost as water vapour.

Teacher's Note:
a) Transpiration mainly occurs through the stomata present on the leaves.
b) Ensure students understand that while minor transpiration can happen through green stems, leaves are the primary site.

4. Which of the following is not good for the eyes? [1 Mark]
(a) Eating vegetables
(b) Looking at the Sun directly
(c) Washing your eyes with cold water
(d) Taking breaks while working on a computer

Answer: (b) Looking at the Sun directly

Looking directly at the Sun can severely damage the retina due to intense solar radiation.

Teacher's Note:
a) Protective eyewear or indirect viewing methods must always be used for solar events.
b) Eating vegetables, washing eyes, and taking screen breaks are healthy habits.

5. Oxygen and carbon dioxide are exchanged at the ___________. [1 Mark]
(a) Nasal cavities
(b) Trachea
(c) Pharynx
(d) Alveoli

Answer: (d) Alveoli

Exchange of gases such as oxygen and carbon dioxide takes place across the thin and moist walls of the alveoli.

Teacher's Note:
a) Alveoli provide a very large surface area for gaseous exchange in the lungs.
b) Capillaries surrounding the alveoli absorb the oxygen into the bloodstream.

6. Which of the following refers to the initial U-shaped part of the small intestine? [1 Mark]
(a) Jejunum
(b) Ileum
(c) Duodenum
(d) Caecum

Answer: (c) Duodenum

Duodenum is the initial U-shaped part of the small intestine that receives secretions from the liver and pancreas.

Teacher's Note:
a) The small intestine is divided into duodenum, jejunum, and ileum.
b) Most chemical digestion of food is completed in the duodenum.

7. Vacuole is a watery sac bounded by a membrane termed as ___________. [1 Mark]
(a) Tonoplast
(b) Chromoplast
(c) Centriole
(d) Cristae

Answer: (a) Tonoplast

Vacuoles are clear cavities filled with cell sap and covered by a cytoplasmic membrane called tonoplast.

Teacher's Note:
a) Plant cells typically possess a large central vacuole that maintains turgidity.
b) Tonoplast is selectively permeable, controlling the movement of substances into the vacuole.

8. The outermost part of a rose flower is [1 Mark]
(a) Sepals
(b) Petals
(c) Stamen
(d) Style

Answer: (a) Sepals

Sepals form the outermost whorl of a flower, protecting the flower in the bud stage.

Teacher's Note:
a) The whorl of sepals is collectively known as the calyx.
b) Petals form the second whorl (corolla) which lies inside the sepals.

9. Which of the following is the main source of energy? [1 Mark]
(a) Proteins
(b) Minerals
(c) Vitamins
(d) Carbohydrates

Answer: (d) Carbohydrates

Carbohydrates are the primary energy-yielding components of our food.

Teacher's Note:
a) Fats also provide energy, but carbohydrates are the body's main and immediate source.
b) Proteins are primarily bodybuilding foods, while vitamins and minerals are protective foods.

10. Which of these connects the leaf to the stem? [1 Mark]
(a) Lamina
(b) Veins
(c) Midrib
(d) Petiole

Answer: (d) Petiole

Petiole is a narrow, stalk-like structure that attaches the leaf blade to the stem.

Teacher's Note:
a) Leaves with a petiole are called petiolate leaves.
b) The lamina is the flat green blade of the leaf.

11. What is the shape of the trees found on the mountains? [1 Mark]
(a) Rod
(b) Spiral
(c) Cone
(d) Straight

Answer: (c) Cone

Trees growing on mountains are typically cone-shaped with sloping branches so that snow slides off easily.

Teacher's Note:
a) Conical shapes prevent the accumulation of heavy snow that could break branches.
b) This is a classic adaptive feature of coniferous trees in high-altitude regions.

12. What is the function of tail in fish? [1 Mark]
(a) Swimming
(b) Changing directions
(c) Respiration
(d) Protection

Answer: (b) Changing directions

Flat fins and the tail in fish help them to change direction and maintain body balance while moving in water.

Teacher's Note:
a) The caudal fin (tail) acts as a rudder for steering.
b) While swimming involves the whole body and multiple fins, the tail specifically aids in steering and propulsion.

13. The corolla is made up of units called ____________. [1 Mark]
(a) Sepals
(b) Petals
(c) Stamens
(d) Style

Answer: (b) Petals

Corolla is the second whorl of the flower made up of brightly coloured units called petals.

Teacher's Note:
a) Petals help attract insects for pollination.
b) Stamens form the male reproductive whorl (androecium).

14. In plant cells, which of the following organelles has smaller units called dictyosomes? [1 Mark]
(a) Cytoplasm
(b) Cell wall
(c) Golgi apparatus
(d) Centrosome

Answer: (c) Golgi apparatus

Dictyosomes are individual stacks of membrane-bound flattened sacs that make up the Golgi apparatus in plant cells.

Teacher's Note:
a) In plant cells, Golgi bodies are scattered and referred to as dictyosomes.
b) They are involved in the modification and packaging of cellular secretions.

15. During photosynthesis plants give out _______________. [1 Mark]
(a) Carbon dioxide
(b) Oxygen
(c) Nitrogen
(d) Carbon monoxide

Answer: (b) Oxygen

During photosynthesis, plants utilise carbon dioxide and water in the presence of sunlight to produce food, releasing oxygen as a byproduct.

Teacher's Note:
a) The released oxygen is essential for the respiration of aerobic organisms.
b) Gaseous exchange occurs via stomata.

Question 2

A. Name the following. [5 Marks]
1. The organelle which digests old or injured parts of its own cell. [1 Mark]

Answer: Lysosome

Teacher's Note:
a) Lysosomes contain powerful digestive enzymes.
b) They are also known as suicide bags of the cell.

2. A thin, sticky film composed of mucous, food particles and bacteria, which develops on the surface of the teeth over a period of time. [1 Mark]

Answer: Plaque

Teacher's Note:
a) Dental plaque produces acids that erode tooth enamel.
b) Regular brushing prevents plaque accumulation and tooth decay.

3. The pattern or arrangement of veins on a leaf. [1 Mark]

Answer: Venation

Teacher's Note:
a) Venation can be reticulate or parallel.
b) Veins provide mechanical support and transport water and minerals.

4. The surface of a tooth. [1 Mark]

Answer: Enamel

Teacher's Note:
a) Enamel is the hard, white outer covering of the crown of a tooth.
b) It is the hardest substance in the human body.

5. Tiny openings found on the lower side of the leaf for the exchange of gases. [1 Mark]

Answer: Stomata

Teacher's Note:
a) Each stoma is guarded by two bean-shaped guard cells.
b) They regulate the opening and closing for gas exchange and transpiration.

B. Fill in the blanks. [5 Marks]
1. The enzyme __________ converts maltose into glucose. [1 Mark]

Answer: Maltase

Teacher's Note:
a) Maltase acts specifically on the disaccharide maltose.
b) Digestive enzymes break down complex food molecules into simple soluble forms.

2. Frogs have ___________ feet which allow them to swim in water. [1 Mark]

Answer: Webbed

Teacher's Note:
a) Webbed feet act like paddles in water.
b) This is an aquatic adaptation seen in amphibians like frogs and aquatic birds like ducks.

3. Fertilisation results in the growth and transformation of the ovary into a ______________. [1 Mark]

Answer: Fruit

Teacher's Note:
a) After fertilisation, ovules develop into seeds, and the ovary matures into a fruit.
b) Other floral parts usually wither and fall off.

4. Centrosome consists of one or two rod-like bodies called ____________. [1 Mark]

Answer: Centrioles

Teacher's Note:
a) Centrioles play an important role in cell division in animal cells.
b) They help in the formation of spindle fibres.

5. One complete sequence of part contraction and relaxation is called ____________. [1 Mark]

Answer: Cardiac cycle

Teacher's Note:
a) A cardiac cycle includes one heartbeat comprising systole (contraction) and diastole (relaxation).
b) It ensures continuous blood circulation through the body.

Question 3

A. Match the following. [5 Marks]

Answer:
1 - C
2 - E
3 - D
4 - A
5 - B

Teacher's Note:
a) Chloroplasts contain chlorophyll for photosynthesis.
b) Amylase is a carbohydrate-digesting enzyme, while erepsin acts on proteins.

B. With the help of a suitable diagram explain the structure and function of the mitochondria and the endoplasmic reticulum. [5 Marks]

[Figure: Diagrams of mitochondria showing outer membrane, inner membrane, cristae, and matrix; and endoplasmic reticulum showing rough ER with ribosomes, smooth ER, and nuclear pore.]

Answer:
Structure of Mitochondria:
1. Mitochondria are oval or rod-shaped structures found scattered throughout the cytoplasm.
2. They are surrounded by a double membrane.
3. The inner membrane has folds called cristae which help to increase its surface area.
4. On the walls of the cristae, food combines with oxygen to produce ATP (Adenosine triphosphate), the primary energy source of the cell.
Functions of Mitochondria:
1. They are termed as the powerhouses of the cell.
2. They convert the chemical energy stored in food into readily usable biological energy.
Structure of Endoplasmic Reticulum:
1. Endoplasmic reticulum consists of a series of membrane-bound tubes and chambers within a cell.
2. Its rough appearance is due to the presence of a large number of ribosomes on its surface.
Functions of Endoplasmic Reticulum:
1. The basic function of the endoplasmic reticulum is to store fats and proteins and serve as the cell transport system.

Teacher's Note:
a) Students should draw neat, labelled diagrams of both organelles to secure full marks.
b) Clearly distinguish between smooth and rough endoplasmic reticulum based on the presence of ribosomes.

Question 4

A. Why is seed dispersal important? Explain the different methods of seed dispersal. [5 Marks]

Answer:
If all the seeds were to germinate in the same place, there would be an unhealthy competition for food, water, sunlight, and space between the parent plant and seedlings. Thus, seed dispersal is important as it scatters seeds far and wide.
Different methods of seed dispersal:
1. Dispersal by explosion: Fruits of plants like pea, bean, and castor burst open once ripe, scattering seeds in all directions.
2. Dispersal by wind: Seeds of certain plants develop wing-like or hairy structures (e.g., Moringa, Calotropis) allowing them to be carried away by the wind.
3. Dispersal by animals: Birds eat fleshy fruits and pass out undigested hard seeds in droppings. Fruits with hooks (e.g., Xanthium) cling to animal fur or human clothing.
4. Dispersal by water: Plants growing along coastal regions (e.g., coconut) produce fruits with a waterproof outer covering that float and are carried away by waves.

Teacher's Note:
a) Emphasize that seed dispersal prevents overcrowding and helps plants colonize new areas.
b) Give correct examples for each method of dispersal.

B. Label the parts in the given diagram. [5 Marks]

[Figure: Human digestive system diagram with pointer 1 indicating Oesophagus, pointer 2 indicating Gall bladder, pointer 3 indicating Stomach, pointer 4 indicating Pancreas, and pointer 5 indicating Small intestine.]

Answer:
1. Oesophagus
2. Gall bladder
3. Stomach
4. Pancreas
5. Small intestine

Teacher's Note:
a) Practice drawing and labelling the human digestive system accurately.
b) Ensure pointers touch the exact organs specified in the diagram.

Question 5

A.
1. How is cactus adapted to survive in a desert? [3 Marks]

Answer:
Cactus is adapted to survive in a desert through the following features:
1. Leaves are modified into spines to prevent water loss through transpiration.
2. The stem is modified to perform photosynthesis and store water.
3. Roots go very deep into the soil to absorb underground water.

Teacher's Note:
a) Desert adaptations revolve around water conservation.
b) Fleshy green stems take over the role of food manufacture in the absence of broad leaves.

2. Why does mountain goat has strong hooves? [2 Marks]

Answer:
The mountain goat has strong hooves for running up the steep, rocky slopes of mountains securely for grazing.

Teacher's Note:
a) Strong hooves provide grip on slippery and uneven mountain terrain.
b) This is a structural adaptation for locomotion in high altitudes.

B. Find the odd one out. [5 Marks]
1. Typhoid, Diphtheria, Tetanus, Measles [1 Mark]

Answer: Measles

Measles is a viral disease, while typhoid, diphtheria, and tetanus are bacterial diseases.

Teacher's Note:
a) Identify the underlying category (bacterial vs viral infections).
b) State the reason clearly for full credit.

2. Dengue, Conjunctivitis, Chicken pox, Measles [1 Mark]

Answer: Dengue

Dengue is spread by mosquitoes, while conjunctivitis, chicken pox, and measles are spread by personal contact.

Teacher's Note:
a) Differentiate between vector-borne and contagious contact diseases.
b) Mosquito-borne transmission is distinct from direct person-to-person spread.

3. Rose, Neem, Acacia, Mango [1 Mark]

Answer: Mango

Mango has simple leaves, while rose, neem, and acacia have compound leaves.

Teacher's Note:
a) Classify leaves based on whether the blade is undivided (simple) or divided into leaflets (compound).
b) Mango leaves are a common example of simple leaves.

4. Night blindness, Beriberi, Diabetes, Pellagra [1 Mark]

Answer: Diabetes

Diabetes is a metabolic disorder, while night blindness, beriberi, and pellagra are vitamin deficiency diseases.

Teacher's Note:
a) Deficiency diseases are caused by a lack of specific vitamins in the diet.
b) Diabetes arises from problems related to insulin production or action.

5. Cell wall, Mitochondria, Cytoplasm, Cell membrane [1 Mark]

Answer: Cell wall

Cell wall is found only in plant cells, while mitochondria, cytoplasm, and cell membrane are found in both animal and plant cells.

Teacher's Note:
a) Plant cells have an outer rigid cell wall made of cellulose.
b) Animal cells lack a cell wall, having only a cell membrane.

Question 6

A. Describe the structure and function of leaves. [5 Marks]

[Figure: Diagram of a leaf showing tip, margin, midrib, vein, lamina, and petiole.]

Answer:
Structure of a leaf:
1. Lamina: The flat, green portion of the leaf also known as the leaf blade.
2. Veins: They form a supporting framework and transport raw materials and manufactured food.
3. Petiole: A narrow, stalk-like structure connecting the leaf to the stem.
4. Midrib: The central vein running down the middle of the leaf from which smaller veins branch out.
Functions of leaves:
1. Photosynthesis: Leaves manufacture food using sunlight, water, and carbon dioxide with the help of chlorophyll.
2. Exchange of gases: Stomata present on the lower surface facilitate the intake of carbon dioxide and release of oxygen.
3. Transpiration: Loss of water vapour through stomata helps in cooling the plant and pulling water and minerals from roots.

Teacher's Note:
a) Structure and functions must be explained separately for clarity.
b) Mentioning stomata is essential for explaining both gas exchange and transpiration.

B. Define the following terms. [5 Marks]
1. Egestion [1 Mark]

Answer: Egestion, also called defecation, is the process of removal of undigested food materials from the body.

Teacher's Note:
a) Egestion is the removal of solid waste from the digestive tract.
b) Do not confuse egestion with excretion, which involves metabolic waste products.

2. Breathing [1 Mark]

Answer: Breathing is a physical process of inhalation and exhalation of gases occurring outside cells, with no release of energy.

Teacher's Note:
a) Breathing is a part of respiration.
b) It simply ventilates the respiratory organs without cellular energy production.

3. Internodes [1 Mark]

Answer: The space between two adjacent nodes on a plant stem is called an internode.

Teacher's Note:
a) Nodes are the regions of the stem where leaves arise.
b) Stem elongation primarily occurs at internodes.

4. Plaque [1 Mark]

Answer: Plaque is a thin, sticky, transparent film formed on the surface of teeth due to bacteria, saliva, and food particles, leading to tooth decay.

Teacher's Note:
a) Plaque bacteria ferment sugars to produce acid.
b) Acid demineralizes tooth enamel.

5. Bisexual flower [1 Mark]

Answer: A flower which contains both male (stamen) and female (pistil) reproductive parts is termed a bisexual flower.

Teacher's Note:
a) Also known as a complete or hermaphrodite flower.
b) Examples include mustard and rose.

Question 7

A. Answer the following in brief.
1. Explain the modifications in the leaf. [3 Marks]

Answer:
Leaves are modified to perform functions other than photosynthesis in certain plants:
1. Support (Tendrils): In weak-stemmed plants like wild peas, leaves or leaflets are modified into tendrils for climbing.
2. Protection (Spines): In desert plants like cacti, leaves are modified into sharp spines to reduce water loss and protect against herbivores.
3. Trapping insects (Pitcher): In insectivorous plants like Nepenthes, leaves form a pitcher shape with digestive fluids to trap insects and fulfil nitrogen requirements.

Teacher's Note:
a) Leaf modifications demonstrate plant adaptation to specific environmental pressures.
b) Provide clear examples for each type of modification.

2. Mention any two adaptations in birds which help them to fly in air. [2 Marks]

Answer:
Two adaptations in birds that help them fly are:
1. Boat-shaped or streamlined, lightweight body to reduce air resistance.
2. Hollow and light bones (pneumatic bones) that reduce body weight.

Teacher's Note:
a) Streamlined bodies ensure smooth movement through the air.
b) Wings and powerful flight muscles are also essential adaptations.

B. Answer the following.
1. Snow leopard shows the presence of rounded body, small ears and big feet. How do these adaptive features help the animal to survive in mountain regions? [2 Marks]

Answer:
1. A rounded body and small ears minimize the body surface area, reducing heat loss from the body in cold mountain regions.
2. Big feet spread the animal weight on snow, preventing it from sinking into soft snow.

Teacher's Note:
a) These are structural adaptations for surviving extreme cold and snowy habitats.
b) Thick fur is another key adaptation in snow leopards.

2. State the importance of transpiration. [3 Marks]

Answer:
The importance of transpiration includes:
(a) Cooling: It keeps the plant body cool during hot weather through evaporation.
(b) Water transport: Water loss creates a suction pull that draws water upwards from the roots through the xylem.
(c) Mineral transport: The pulled water from roots carries dissolved minerals to all parts of the plant.

Teacher's Note:
a) Transpiration acts as a driving force for the ascent of sap in tall plants.
b) It links water uptake by roots to atmospheric evaporation.