CBSE Previous Year Question Papers Class 10 Biology – 2023

CBSE Class 10 Previous Year Question Papers for Biology help you to understand the level of questions asked in the previous exams, along with the changes in pattern. Practicing class 10 PYQ enhances time-management skills while appearing in the board examination. CBSE 10th biology previous year’s paper makes you understand the importance of different topics that have been asked previously.

Solving previous year questions will boost your confidence level to appear in the examination with proper knowledge of different topics that will be asked. PYQ for class 10 enhances the understanding of the topic and acts as a checkpoint to see the level of preparation you have done. 

Students are also advised to go through CBSE Class 10 Biology Sample Papers with answers on the official website of Geeks for Geeks for a better understanding of the exam pattern. You can find the CBSE class 10 biology previous year question paper with solutions pdf for free download here.

Overview of CBSE Class 10 Biology Paper – 2023 

A detailed overview of the CBSE Class 10 pyq Biology – 2023 is given below:

Number of Questions Asked	13
Total Time Allotted	3 hours
Paper Section	3 Sections (A, B, C, D and E) – All Compulsory
Types of Questions Asked	Short Answer Types, Long Answer Types, Case Study, and MCQs

CBSE Class 10 Biology Solved Question Paper – 2023

Question 1: Select from the following the correct statement about tropic movement in plants:

• (a) It is due to the stimulus of touch and temperature.
• (b) It does not depend upon the direction of stimulus received.
• (c) It is observed only in roots and not in stems.
• (d) It is a growth related movement.

Answer:

(d) Trophic movements are growth movements that happen in the stimulus’s direction. In this instance, the reaction affects the protoplasm from one angle. A tropic movement may travel in the stimulus’s direction or away from it.

Question 2: The statement that correctly describes the characteristic(s) of a gene is:

• (a) In individuals of a given species, a specific gene is located on a particular chromosome.
• (b) A gene is not the information source for making proteins in the cell.
• (c) Each chromosome has only one gene located all along its length.
• (d) All the inherited traits in human beings are not controlled by genes.

Answer:

(a) A gene has a specific position on a certain chromosome in an individual of that species. There is an allele, which is a different version of a gene. Homologous chromosomes have alleles at the same location.

Question 3: Consider the following statements about small intestine and select the one which is NOT correct:

• (a) The length of the small intestine in animals differs as it depends on the type of food they eat.
• (b) The small intestine is the site of complete digestion of food.
• (c) The small intestine receives secretions from liver and pancreas.
• (d) The villi of the small intestine absorb water from the unabsorbed food before it gets removed from the body via the anus.

Answer:

(d) In vertebrates, the large intestine is the last segment of the digestive system. Here, water is absorbed, and the leftover waste is held in feces until it is eliminated by egestion or defecation.

Question 4: An organism which breaks down the food material outside the body and then absorbs it is

• (a) a plant parasite, Cuscuta.
• (b) an animal parasite, Tapeworm.
• c) a bacteria, Rhizobium.
• (d) a fungi, Rhizopus

Answer:

(d) Fungi are organisms that break down food into basic compounds outside of the body before absorbing it. Examples of fungi include yeast, mushrooms, and bread mold.

Question 5 and 6: These consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:

• (a) Both (A) and (R) are true and (R) is the correct explanation of (A).
• (b) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
• (c) (A) is true, but (R) is false.
• (d) (A) is false, but (R) is true

Assertion (A): The anaerobic respiration which takes place in yeast, has one of the end products as an acid. Reason (R): During anaerobic respiration, there is incomplete breakdown of glucose.

Answer:

(A) is false, but (R) is true. Yeast and other bacteria break down food, such as glucose, into ethanol and carbon dioxide, and they release energy when there is no oxygen present.

Assertion (A): Genes inherited from the parents decide the sex of a child. Reason (R): X chromosome in a male child is inherited from his father.

Answer:

(A) is true, but (R) is false. Male humans have XY chromosomes, whereas female humans have XX chromosomes. Both X and Y chromosomal gametes are produced by the male. There is just one kind of X chromosome gamete produced by the female. Men always inherit their mother’s X chromosome and their father’s Y chromosome.

Section B

Question 7: List two reasons to show that the existence of decomposers is essential in an ecosystem.

Answer:

• Decomposers are organisms that eat dead or decaying organic substances.
• Microorganisms such as bacteria and fungus are known as decomposers because they have the ability to break down organic material that is dead or decaying and release nutrients.

Reasons showing the existence of decomposers are important in the ecosystem:

• It is decomposers who recycle the nutrients. This facilitates the release of the nutrients into their natural reservoir. For example, carbon from the deceased animal will return in less complex forms—carbon dioxide—to the air in the pool.
• Waste is broken down by the decomposing microbe, preventing it from becoming a haven for pathogens. Without the decomposers, the deceased organisms will likewise remain in their current state.

Question 8: Name the part of the human excretory system where nephrons are found. Write the structure and function of nephrons.

Answer:

Each of your kidneys is made up of about a million filtering units called nephrons.

Nephrons:

1. The kidney’s functional unit is the nephron.
2. A renal tubule and a renal corpuscle make up this structure.

Structure of nephrons:

• Nephrons are basic filtering units of kidneys.
• Each kidney possesses a large number of nephrons (approx. 1-1.5 million).
• The components of the nephron:
• Glomerulus,
• Bowman’s capsule
• Long renal tubule

Functions of nephron:

1. The renal artery, which divides into capillaries connected to the glomerulus, allows blood to reach the kidney.
2. The solute and water are moved to Bowman’s capsule.
3. Selective reabsorption of glucose and salts occurs in the proximal convoluted tubule.
4. Filtrate now descends into the Henle loop.
5. Proceed to the distal convoluted tubule and ultimately enter the collecting duct after that.

Question 9: Write the sequence of events that involve the response of a person when a dust particle is inhaled through the nose by him.

Answer:

1. Following inhalation of a dust particle through the nose, the following happens:
2. The dust particle passes via the nasal passages after entering the nostrils.
3. Mucous membranes that secrete mucus line the nasal passages. The dust particle becomes stuck in the mucus.
4. Mucus containing the trapped dust particle is moved towards the back of the throat by microscopic hair-like structures on the nasal tube surface known as cilia.
5. To remove the dust particle and associated mucus from their body, the individual may cough or swallow.
6. The immune system may be triggered if the dust particle enters the lungs and causes irritation.
7. Breathing becomes challenging because to inflammation and swelling in the airways caused by the production of histamine and other substances during the immunological response.
8. Shortness of breath, wheezing, and coughing are possible symptoms for the person.
9. The reaction can be more severe and necessitate medical treatment if the person already has a pre-existing illness, such allergies or asthma.

Section C

Question 10: . (a) (i) Why does a kitchen garden called an artificial ecosystem while a forest is considered to be a natural ecosystem? (ii) While designing an artificial system at home, write any two things to be kept in mind to convert it into a self-sustaining system. Give reason to justify your answer.

OR

(b) (i) Construct a food chain of four trophic levels comprising the following: Hawk, snake, plants, rat. (ii) 20000 J of energy was transferred by the producers to the organism of second trophic level. Calculate the amount of energy that will be transferred by organisms of the third trophic level to the organisms of the fourth trophic level.

Answer:

(i) A kitchen garden is sometimes seen as an artificial ecosystem because it is designed and maintained by humans, who utilize different methods to encourage the development of particular plants, including fertilizer, irrigation, and pest control. The plants in the garden are usually chosen for their aesthetic worth, food value, or potential to produce herbs. The garden is usually created to suit the needs and preferences of the gardener.
A forest, on the other hand, is regarded as a natural ecosystem as humans do not directly affect or control it. Over time, the flora, fauna, and temperature of a forest have changed to accommodate local soil, climate, and other environmental conditions. Even while people can engage in activities like hiking, hunting, and lumber harvesting, a forest’s natural processes—such as photosynthesis, decomposition, and nutrient cycling—maintain its ability to sustain itself.
All things considered, the primary distinction between a man-made ecosystem such as a kitchen garden and a naturally occurring ecosystem such as a forest is in the extent of human involvement and oversight in both its establishment and upkeep.

(ii) To establish a self-sustaining artificial environment at home, there are a few key considerations that must be made. Here are two important things to remember:

1. Employ a variety of plants: Biodiversity is one of the most important components of an ecosystem that can support itself. You may establish a healthy ecosystem that is more self-sufficient and less dependent on outside inputs like pesticides and fertilizers by growing a wide variety of plants. This is due to the fact that every species of plant has certain needs that when combined can contribute to the creation of a balanced environment that is home to a wide range of beneficial insects, pollinators, and other creatures.
2. Include natural nutrient cycle: Nutrient cycling is necessary for a self-sustaining environment. Nutrient cycling between organisms should be a natural feature of the ecosystem, rather than depending on artificial fertilizers or other outside inputs. Compost or other organic materials, for instance, can be used to enrich the soil with nutrients that plants can absorb. The nutrients from the plants are then returned to the soil for use by the following generation of plants when they die or are harvested.

OR

(i) The term “food chain” describes the sequence of events in an ecosystem in which a living thing feeds another living thing, which is then eaten by a larger creature. A food chain is created when nutrients and energy are transferred between organisms at various trophic levels.
Plants → Rats → Snakes → Hawks

(ii) Generally, 10% or so of the energy available at a given trophic level is transmitted to the subsequent level. The 10% rule applies to this. As a result, the following formula may be used to determine how much energy will be transported from third-trophic level organisms to fourth-trophic level species:

Energy available at the third trophic level = 10% of the energy available at the second trophic level = 0.1 x 20,000 J = 2,000 J

Therefore, 2,000 J of energy will be transferred from the organisms of the third trophic level to the organisms of the fourth trophic level.

Question 11: (a)

(i) State the role of ATP in cellular respiration.

(ii) What ensures sufficient exchange of gases in plants?

iii) State the conditions on which the direction of diffusion of gases in plants depend upon.

OR

(b)

(i) What is the internal energy reserve in plants and animals?

(ii) How desert plants perform photosynthesis if their stomata remain closed during the day?

Answer:

(a) (i) The energy produced during cellular respiration is instantly put to use in the production of ATP, a molecule that powers every other function in the cell. ATP is broken down in these activities to provide a set quantity of energy that can power the cell’s endothermic reactions.
(ii) All of the cells in a plant are in touch with air because of the vast intercellular gaps and the stomata that allow for gas exchange. Here, diffusion is used to exchange oxygen and carbon dioxide. They may enter cells or exit them and take to the air.
(iii) The plant’s needs and the surrounding circumstances determine the diffusion’s direction.
It is necessary to preserve the ion concentration gradient and adjust the plants’ membrane potential to maintain the direction of diffusion.

OR

(b) (i) Carbohydrates that are not utilized right away are stored as starch, which acts as the plant’s internal energy reserve and is used as needed. Animals store part of the energy they receive from their meal as glycogen in their bodies.

(ii) During the night, desert plants absorb carbon dioxide and create an intermediate that is subsequently affected by the energy that chlorophyll absorbs during the day.

Section D

Question 12:

(a) What happens when the egg is not fertilised?

(b) How is sperm genetically different from a human egg/ova?

(c) List any three contraceptive methods practised for family planning. Mention how these methods work.

Answer :

(a) The endometrium, the inner lining of the uterus that is primarily maintained for the implantation of fertilized eggs, degenerates and is released from the uterus as menstural bleeding if the egg is not fertilized. We refer to this process as menstruation.

(b)

• Sperm are the male gametes that fertilize with the female gamete.
• An ovum is the female egg that is fertilized after a sexual encounter.
• The female egg has XX+22 chromosomes, whereas the sperm has XY+ 22 chromosomes.
• Following fertilization, a zygote develops into an embryo, and eventually a newborn, whose gender is determined by the mother’s and father’s respective sets of chromosomes.

(c) Artificial methods or techniques, such as contraception, are primarily employed to prevent pregnancy resulting from sexual activity.
Contraception:

1. A contraceptive technique or device is one that prevents conception.
2. It is sometimes referred to as fertility control, anticonception, or birth control.

Methods of contraception:

• Barriers: Devices known as barrier contraceptives work by preventing sperm from accessing the uterus in order to prevent pregnancy. Among them are diaphragms, cervical caps, spermicide-containing contraceptive sponges, female and male condoms. Condoms are the most widely used birth control technique among them.
• Intra-uterine devices (IUDs): Intrauterine contraceptive implants are placed inside the uterus to prevent conception by functioning as a barrier. Copper-T prevents conception by releasing copper ions, which cause sperm to resent each other by altering their motion pattern.
• Oral contraceptives: Oral pills, often known as progestogens or progesterone-estrogen combinations, are tablets that women take in small dosages. Pills impede ovulation and implantation and change the quality of cervical mucus, which limits or delays sperm entrance into the female vaginal canal.

Section E

Question 13: In order to trace the inheritance of traits Mendel crossed pea plants having one contrasting character or a pair of contrasting characters. When he crossed pea plants having round and yellow seeds with pea plants having wrinkled and green seeds, he observed that no plants with wrinkled and green seeds were obtained in the F1 generation. When the F1 generation pea plants were cross-bred by self-pollination, the F₂ generation had seeds with different combinations of shape and colour also.

(a) Write any two pairs of contrasting characteristics of the pea plant used by Mendel other than those mentioned above.

(b) Differentiate between dominant and recessive traits.

(c) State the ratio of the combinations observed in the seeds of F₂ generation (in the above case). What do you interpret from this result?

Answer:

(a) Seven pairs of contrasting characteristics of pea plants studied by Mendel in his experiments are as follows:-

I. Pea shape: Round or Wrinkled.

II. Pea color: Green or Yellow.

III. Pod shape: Constricted or Inflated.

IV. Pod color: Green or Yellow.

V. Flower color: Purple or White.

VI. Plant size: Tall or Dwarf.

VII. Position of flowers: Axial or Terminal.

(b) Difference Between Recessive and Dominant Traits

Chracteristics	Dominant Trait	Recessive Trait
Features	Even in cases when there is only one copy of the linked allele, dominant features are always shown.	Only when both linked alleles are recessive can recessive features manifest. A dominant allele reduces the likelihood that the correlated trait will appear.
Presentation	Dominant allele is denoted by a capital letter	Recessive allele is denoted by a small letter
Traits	V-shaped hairline Almond-shaped eyes Right handedness Detached earlobes Dark hair Brown eyes	Straight hairline Round eyes Left handedness Attached earlobes Blond hair, red hair Blue eyes (can also be a polygenetic trait)

(c) The ratio of combinations found in F₂ generation seeds is 9:3:3:1. Some of the F2 offspring in the cross seen above are tall plants with spherical seeds, while others are shorter plants with wrinkled seeds. A few F2 offspring had novel combinations. While some are small with spherical seeds, others are tall with wrinkled seeds. When variables governing seed color and shape recombine to generate zygotes that result in F2 offspring, new combinations of characteristics are formed in the F2 offspring. Consequently, the round seed/wrinkled seed trait and the tall/short trait are inherited separately.

OR

(c) Given below is a cross between a pure violet flowered pea plant (V) and a pure white flowered pea plant (v). Diagrammatically explain what type of progeny is obtained in F1, generation and F2, generation:

Pure violet flowered plant x Pure white flowered plant.

(VV) (vv)

Answer:

The cross is studied by monohybrid cross since it involves only one trait which is the flower color.

Conclusion – CBSE Class 10 Biology Question Paper 2023

Solving CBSE class 10 biology previous year question paper give you a chance to judge your preparations before examinations. The main purpose of providing the class 10 PYQ is to give an idea about exam pattern and the types of questions asked in exam. Questions are often repeated in exams as well. Hence, solving CBSE 10th biology previous year paper is important while studying. CBSE Previous Year Question Papers Class 10 Biology 2023 is available here.

FAQs – CBSE Class 10 Previous Year Question Paper for Biology (2023)

How was CBSE 10th Science question Paper 2023?

Science paper was rated as moderately easy. While the questions largely followed NCERT content, a few students felt that the paper was lengthy.

Why Solve CBSE Previous Year Question Papers Class 10 Science?

Practicing past Class 10 Science question papers from previous years will serve as a review for students, as these CBSE Class 10 Science question papers encompass the entirety of the CBSE Class 10 syllabus, including key topics.

Will the CBSE Science previous year papers of Class 10 help students understand the question paper format?

Reviewing past CBSE Class 10 Science papers from previous years will help students in grasping the format of the question paper, the types of questions posed, and the marking scheme followed by the CBSE board.

Why is the CBSE Class 10 Science Previous Year Papers useful for the students?

The previous year Science papers offer CBSE Class 10 students valuable insight into the formats and types of questions commonly asked in board exams.

Where can I Find CBSE Class 10 Biology Previous Year Question Paper?

You can find CBSE Class 10 biology previous year question paper on the official site of Geeks for Geeks.

CBSE Class 10 Biology Previous Year Question Paper with Solutions pdf?

You can download CBSE Class 10 biology previous year question paper with solutions pdf on the official site of Geeks for Geeks.

What are the Tips to Score High Marks in CBSE Class 10 Biology Exam?

To score high marks in CBSE Class 10 Biology, focus on understanding concepts, practice diagrams, and solve previous year papers for getting used to of the exam pattern. Regular revision helps in retaining concepts.

What is the Best Book for CBSE Class 10 Biology Preparation?

Studying NCERT along with any reference book is enough for the preparation of class 10 boards.