Science Olympiad Model Test Paper - 1 | Science Olympiad Class 7 PDF Download

Ans: (c)

According to the question,

4³ - 1 = 63

(4 + 1)³ + 1 = 126

Similarly,

6³ - 1 = 215

(6 +1)³ + 1 = 344

Ans: (c)

• The phrase "my father's mother-in-law" refers to Urvi's grandmother on her father's side.
• The only son of Urvi's grandmother would be Urvi's uncle.
• Since this uncle is the son of her father's mother, he is also Urvi's maternal uncle.
• Thus, the man in the photograph is Urvi's maternal uncle.

Ans: (c)

• The code shifts each letter in 'MASTER' to the next letter in the alphabet, with a specific pattern.
• For example, 'M' becomes 'B', 'A' becomes 'N', and so on.
• Applying the same pattern to 'REVISION', we find that it translates to 'FSJWJTOP'.
• Thus, the correct encoded form of 'REVISION' is 'FSJWJTOP'.

Ans: (c)

• To find the answer, we need to look for the letter K in the arrangement.
• We check if each K is preceded by a consonant and followed by a vowel.
• After examining the sequence, we find that there are three K's that meet these criteria.
• Thus, the correct answer is (c) Three.

Ans: (a)

The given pattern is made up of two series:

(i) E, F, G, ?

(ii) M, L, K, ?

Now, in the first series, the pattern is to add 1.

So, E + 1 = F

F + 1 = G

G + 1 = H

In the second series, the pattern is to subtract 1.

So, M - 1 = L

L - 1 = K

K - 1 = J

Therefore, the missing terms are H and J.

Ans: (b)

According to the question,

ACE : IKM

The pattern followed is as follows:

A + 8 = I

C + 8 = K

E + 8 = M

Now, out of the given options, the same rule is applied for option 2 as follows:

R + 8 = Z

T + 8 = B

V + 8 = D

Ans: (b)

In this series, each number is repeated, then 13 is subtracted to arrive at the next number.

So, 27 - 13 = 14

Hence, option (b) is the correct answer.

Ans: (c)

• First, replace the symbols with their meanings: 15 P 12 Q 12 R 4 S 3 becomes 15 – 12 + 12 ÷ 4 × 3.
• Next, follow the order of operations: perform division and multiplication first.
• Calculate 12 ÷ 4 = 3, then 3 × 3 = 9.
• Now, substitute back: 15 – 12 + 9 = 15 – 3 = 12.

Ans: (b)

• To determine the direction of town S from town P, we first note that town P is to the West of town Q.
• Next, town R is South of town P, placing it directly below town P.
• Then, town S is East of town R and also South of town Q, which means it is positioned to the South-East of town P.
• Thus, the correct answer is South-East.

Ans: (d)

• To find the total number of girls, we first note that Sheetal is 15th from the left and Sapna is 10th from the right.
• There are 3 girls between them, which means the positions are: Sheetal (15th), 3 girls, and then Sapna.
• So, the position of Sapna from the left can be calculated as: 15 (Sheetal's position) + 3 (girls in between) + 1 (for Sapna) = 19th from the left.
• Now, since Sapna is 10th from the right, we can set up the equation: Total girls = Position from left + Position from right - 1 = 19 + 10 - 1 = 28.

Ans: (a)

Rainforest is found generally near the equator. Places near the equator receive more sunshine and, therefore, more rainfall. This makes the place hot and humid. Temperatures vary from 15oC to 40oC generally near the equator. Rain forests are also present in some tropical areas.Tropical rainforests are warm and moist; while temperate rainforests are cool. To be a tropical rainforest, forested areas must lie between the Tropic of Cancer and the Tropic of Capricorn. One third of the world's tropical rainforests are in Brazil.

Ans: (d)

Cockroaches and other insects breathe through spiracles and tracheae. There is a network of hollow tubes running through the body of an insect. These hollow tubes are called trachea. Each trachea opens on the body surface in the form of very small pore. These pores are called spiracles.

Ans: (b)

• Statement I is correct because work is indeed done to break the bonds in the solid ice structure as it melts.
• Statement II is also correct since energy is absorbed during the melting process, which raises the temperature of the water formed.
• Statement III is incorrect because energy is not absorbed to decrease the temperature; rather, it is absorbed to change the state from solid to liquid.
• Thus, the correct answer is (b) I and II only, as both these statements accurately describe the process of melting ice.

Ans: (a)
Bases have bitter taste and soupy in touch.

Ans: (c)
Amphoteric oxides are the oxides which react both with acids as well as bases.

ZnO + 2HCl → ZnCl₂ + H₂O 
ZnO + 2NaOH → Na2ZnO₂ + H₂O

Ans: (a)

• The magnetic field strength of an electromagnet is not fixed; it can be adjusted based on various factors.
• By changing the current flowing through the coil or the number of turns in the coil, the strength can be increased or decreased.
• This flexibility is what makes electromagnets useful in many applications, as they can be tailored to specific needs.
• Thus, the correct answer is that the magnetic field strength can be varied.

Ans: (b)
The formula of washing soda is Na₂CO₃·10H₂O

Ans: (c)

• Sunil and Rohit both run to the end of the street and then return to the origin.
• During the return, Sunil is ahead of Rohit, meaning he has covered more ground.
• However, since they both started and ended at the same point (the origin), their displacement from the origin is the same.
• Thus, Sunil has run a greater distance but his displacement is lesser than Rohit’s because Rohit has not gone as far back.

Ans: (a)

During intense exercise, there may not be enough oxygen available to complete the process, so a substance called lactate is made. Our body can convert this lactate to energy without using oxygen.

Ans: (c)

KOH solution should be taken in the small test tube inside the flask and water should be taken in the beaker.

Ans: (b)

• When magnesium ribbon is burned, it produces magnesium oxide, which is basic in nature.
• When this ash is dissolved in water, it forms a solution that turns red litmus blue, indicating it is a basic solution.
• Additionally, it turns phenolphthalein pink, which further confirms its basicity.
• Thus, the correct answer is that the solution is basic.

Ans: (c)

• Blood cells and plasma are separated using centrifugation, which spins the mixture to separate components based on density.
•  Petrol and water can be separated using a separating funnel, which allows the two liquids to layer and be drained separately.
• Iron filings and sand are not separated by threshing, but rather by sieving, which uses a mesh to filter out different particle sizes.
• Salt and water can be separated by evaporation, where water evaporates, leaving salt behind.

Ans: (a)

Earthworms breathe through their skin. The skin of an earthworm always remains moist, which helps in breathing.

Ans: (a)

While collecting nectar, the bees also carry pollen grains with them. Pollen grains are produced in the anther which is represented by Q.

Ans: (a)

• Methyl orange shows red colour in acidic medium and would remain orange with water.
• Hence, option (a) is correct.
• Clove oil would retain its odour with both acid and water.
• Phenolphthalein is colourless in acidic as well as neutral medium.
• Both acid and water will have no effect on red litmus paper.

Ans: (a)

• Both statements are true: SO₂ gas does indeed turn the China rose indicator dark pink/magenta when dissolved in water.
• SO₂ is a non-metallic oxide: It reacts with water to form an acidic solution, which explains the color change in the indicator.
• Correct explanation: Statement 2 accurately explains why statement 1 is true, as the acidic nature of the solution affects the indicator's color.
• Thus, the correct option is (a), as both statements are true and the second statement explains the first.

Ans: (c)

• The correct answer is (c) because when an iron nail is placed in a blue copper sulfate solution, a chemical reaction occurs, leading to the formation of a brown deposit of copper on the nail.
• This happens due to the displacement reaction where iron displaces copper from the solution.
• Options (a) and (b) are incorrect as they misrepresent the reactions and processes involved.
• Option (d) is also incorrect because crystallization is a physical change, not a chemical one.

Ans: (d)

From the options given, only pollen represents the male gamete structure. Therefore, it will have half the number of chromosomes present in other cells.

Ans: (c)

• Statement 1 is true because cartilage is indeed found at the ends of bones in joints and in the ear.
• Statement 2 is false because cartilage is actually a flexible tissue, allowing for movement and support.
• Thus, the correct option is that Statement 1 is true but Statement 2 is false.
• This means that while cartilage serves important functions, it is not accurate to say it lacks flexibility.

Ans: (a)

Optics is the study of light. Optics, a segment of physics, evaluates and analyses the properties and behaviours of light.

Ans: (b)

• Paramecium is a single-celled organism that is covered in tiny hair-like structures known as cilia.
• These cilia help it to move and also assist in feeding by sweeping food particles into its oral groove.
• Amoeba, on the other hand, uses pseudopodia for movement and feeding, while yeast and jellyfish do not have cilia.
• Thus, the correct answer is Paramecium, as it is specifically known for having cilia all over its body.

Ans: (b)
Strong alkalis undergoes complete ionisation in water that produces a high concentration of hydroxide ions into the solution.

Ans: (c)
Sulphuric acid (H2SO4) is a strong acid which completely ionises into ions.

Ans: (c)
The pH value of a solution indicates the acidic or basic nature of the solution. If the pH value is less than 7 (e.g., sulphuric acid), then the solution is acidic in nature and if more than 7 (e.g. sodium hydroxide), then the solution is basic in nature. Therefore, the correct decreasing order of solutions based on pH value is : 
Sodium hydroxide > water > sulphuric acid 

Ans: (a)

• Natural fibres can come from both plants and animals, not just plants. This makes option (a) incorrect.
• Option (b) is true because lint refers to the cotton fibres that are separated from the seeds.
• Option (c) is correct as yarns are indeed used in the processes of knitting and weaving to make fabrics.
• Option (d) is also accurate since the cotton plant does grow well in black soil, which helps retain moisture.

Ans: (d)

• Vitamin C is essential for our health and is found in high amounts in oranges.
• A lack of vitamin C can lead to a condition known as scurvy, which causes symptoms like fatigue and bleeding gums.
• The other options mention conditions related to different vitamins, such as night blindness (Vitamin A), pellagra (Niacin), and goitre (Iodine).
• Thus, the correct statement is that vitamin C is abundant in oranges and its deficiency results in scurvy.

Ans: (b)

• Statement I: This is true. Patanwadi sheep are indeed found in the state of Gujarat, particularly in the Saurashtra region.
• Statement II: This is also true. The wool produced by Patanwadi sheep is used for hosiery and other textile products due to its quality.
• Reasoning: While both statements are true, the use of Patanwadi wool for hosiery is not the reason for the sheep being found in Gujarat. They are found there due to environmental conditions suitable for sheep farming and wool production, but the use of the wool is a separate characteristic of the breed. Therefore, option (b) accurately captures that both statements are true but not causally linked.

Hence, option (b) is correct.

Ans: (d)

• Phloem tubes are not limited to the leaves; they are present throughout the plant, transporting sugars made in the leaves to other parts.
• Anaemia is actually related to a deficiency of red blood cells, not white blood cells.
• In a healthy individual, there are far more red blood cells than white blood cells in the blood.
• Thus, the correct choice is None of these as all other statements are incorrect.

Ans: (c)

Stomata are critical for gas exchange in the leaves.
Lenticels are involved in gas exchange in stems.
Roots primarily absorb nutrients and water.
Leaves perform gas exchange via stomata.

Ans: (c)

• Roots: Mainly responsible for anchoring the plant and absorbing water and nutrients from the soil.

• Stems: Support the plant and transport nutrients and water between roots and leaves, but they are not the primary site for photosynthesis.

• Leaves: The main site for photosynthesis, where chlorophyll captures sunlight to convert carbon dioxide and water into glucose and oxygen.

• Flowers: Primarily involved in reproduction and do not play a significant role in photosynthesis.

Thus, the correct answer is leaves, as they are specifically adapted for photosynthesis.

Ans: (b)

• Thick and long hair indicates that the animal is adapted to cold environments, which is typical for the Yak.
• The presence of a large chest and lungs suggests it needs to breathe well in high altitudes, where Yaks are commonly found.
• Strong hooves and horns are characteristics of Yaks, helping them navigate rugged terrains.
• Other options like Snow leopard and Tiger do not fit all the criteria, making Yak the correct choice.

Ans: (d)

• Vegetative propagation is a method of plant reproduction that does not involve seeds.
• One of the main advantages is that the traits of a species can be conserved, ensuring that the new plants are identical to the parent.
• This method is particularly useful for plants that do not reproduce sexually, allowing for their multiplication.
• Additionally, it is rapid, easier, and less expensive compared to other methods, making it a preferred choice for many gardeners and farmers.
• Therefore, the correct answer is that all these points highlight the advantages of vegetative propagation.

Ans: (d)

• Forests provide a wide range of resources that are essential for various industries and health.
• They are a significant source of timber, which is used in construction and furniture.
• Additionally, forests are rich in medicinal plants that are used in traditional and modern medicine.
• Moreover, they produce resin and gum, which have various applications in products like adhesives and cosmetics.
• Therefore, the correct answer is All of these as forests contribute multiple resources.

Ans: (b)
The acid reacts with base to form salt and water. This type of reaction is known as neutralisation reaction.

Ans: (a)
Turmeric is an acid base indicator, which changes colour when the solution turns acidic or basic. Turmeric contains a chemical called curcumin, which remains yellow in an acidic or neutral solution, but turns red in a base.

Ans: (b)

Since the salt solution formed gives a green colour with universal indicator, the salt is a neutral salt and will be formed in a neutralization reaction between a strong acid and a strong base.

Hence, option (b) is correct.

NOTE: Acetic acid (CH₃COOH) is a weak acid and Ammonium hydroxide (NH₄OH) is a weak base.

Ans: (a)

Silk is a natural protein fibre, some forms of which can be woven into textiles. The fibre is composed mainly of fibroin protein, which is produced by the larvae (silk worms) to form cocoons. Sericin is the binding protein which binds the solid fibre (fibroin).

Ans: (d)

• In humans, there are different types of teeth that serve specific functions: X for biting and cutting, Y for crushing and grinding, and Z for tearing food.
• Option D states that X, Y, and Z together total 10 teeth in the upper jaw of an adult, which is correct based on the classification of teeth.
• Other options incorrectly state the number of specific types of teeth, making them inaccurate.
• Understanding the types of teeth and their functions helps clarify why option D is the right choice.

Ans: (c)

For transportation in plants, there are two main tissues viz. xylem and phloem. These are composed of narrow tube-like structures. Xylem is responsible for transport of water, while phloem is responsible for transport of food.

(A) shows xylem and (B) shows phloem.

Ans: (a)

• Digestion of food is a chemical change.
• Cutting of a log of wood into pieces is a physical change.
• Rotting of fruits and vegetables is a chemical change. It occurs when saprophytic microbes decompose the organic matter by secreting some digestive enzymes.
• Evaporation of water from the water bodies is a physical change.

Hence, statements I and IV are false.