Biology Official Board 2024-2025 (English Medium) ICSE Class 10 Question Paper Solution

The number of live births per thousand people per year is called ______.

Mortality

Population density

Population growth rate

Natality

The structure that lies at the junction of the choroid and the iris and is itself a part of the choroid is called ______.

Ciliary body

Suspensory ligament

Pupil

Lens

Assertion (A): Seminal vesicles pour an alkaline secretion into the semen as it passes through the ureter.

Reason (R): The female vagina is acidic and needs to be neutralized for sperm survival.

(A) is true and (R) is false.

(A) is false and (R) is true.

Both (A) and (R) are true.

Both (A) and (R) are false.

The hormone that induces vigorous contractions of the uterus in a pregnant mother is ______.

Oestrogen

Prolactin

Oxytocin

Progesterone

A scientist wanted to conduct a genetic experiment on mice. He cut the tails of all the mice and made them reproduce. What will be the phenotype of the offsprings?

All the offsprings will be tailless.

There will be a mix of tailed and tailless offsprings.

All the offsprings will have tails.

Tail of the offsprings cannot be predicted.

Assertion (A): A turgid plant cell is in a balanced state.

Reason (R): In a turgid cell, turgor pressure and wall pressure are equal and in the same direction.

(A) is true and (R) is false.

(A) is false and (R) is true.

Both (A) and (R) are true.

Both (A) and (R) are false.

The optimum temperature for photosynthesis is ______.

10 – 15°C

60 – 65°C

40 – 45°C

25 – 35°C

Ajay and Vijay are siblings. Ajay can roll his tongue while Vijay cannot. What is the genotype of their parents?

Both the parents are homozygous dominant.

Both the parents are homozygous recessive.

One parent is homozygous dominant, and the other is homozygous recessive.

Both the parents are heterozygous dominant.

Assertion (A): Deficiency of Antidiuretic hormone causes an increase in urination.

Reason (R): Antidiuretic hormone acts on the kidney to reabsorb water from the kidney tubules.

(A) is true and (R) is false.

(A) is false and (R) is true.

Both (A) and (R) are true.

Both (A) and (R) are false.

A phase of cell division where the spindle fibres disappear is ______.

Telophase

Prophase

Metaphase

Anaphase

Assertion(A): Arachnoid layer helps in speeding up the transmission of nerve impulses along the axons.

Reason(R): Axon endings at the synapse secrete acetylene.

(A) is true and (R) is false.

(A) is false and (R) is true.

Both (A) and (R) are true.

Both (A) and (R) are false.

Many nuclear power plants are constructed near water sources. They use water for cooling their machinery and release it back into the water stream. Identify the kind of pollution caused.

Radiation pollution

Water pollution

Industrial pollution

Thermal pollution

Owls are nocturnal animals. They are active at night and hunt small animals for food. Owls have large eyes and can see well at night. This is due to ______.

Cones and Rhodopsin

Rods and Iodopsin

Rods and Rhodopsin

Cones and Iodopsin

Sunil tried to match the tropic movements in plants with the stimulus they respond to. The tabulation is given below:

Identify the correct pair:

P and R

Q and S

R and S

P and S

Observe the following picture, identify the defect and the cause of the defect.

Simple goitre, under secretion of thyroxine.

Ex-ophthalmic goitre, over secretion of thyroxine.

Simple goitre, over secretion of thyroxine.

Ex-ophthalmic goitre, under secretion of thyroxine.

Name the following:

The fully developed part of the ovary containing a mature egg.

Name the following:

The wax-like layer on the epidermis of leaves which reduces transpiration.

Name the following:

The ear ossicle in contact with the oval window of the inner ear.

Name the following:

The physiological process which is the starting point of all food chains.

Name the following:

An insect which is a classic example of natural selection due to industrial melanism.

Given below is the diagram of a human heart. Read the information below the diagram and fill in the blanks:

The heart is enclosed by a membrane called (a) ______. The ventricles give rise to two large blood vessels called (b) ______ and (c) ______. The flaps of the cuspid valves are kept in position by (d) ______. (e) ______ arteries supply oxygenated blood to the walls of the heart.

Arrange the terms in the group in the correct order. Write them in a logical sequence beginning with the term that is underlined.

Palisade cells, Cuticle, Upper epidermis, Spongy cells.

Arrange the terms in the group in the correct order. Write them in a logical sequence beginning with the term that is underlined.

Hepatic portal vein, Stomach, Hepatic vein, Liver.

Arrange the terms in the group in the correct order. Write them in a logical sequence beginning with the term that is underlined.

Cyton, Dendrites, Synaptic cleft, Axon endings.

Arrange the terms in the group in the correct order. Write them in a logical sequence beginning with the term that is underlined.

Insulin release, High blood sugar, Lowers blood sugar, Stimulates glucose uptake from blood.

Arrange the terms in the group in the correct order. Write them in a logical sequence beginning with the term that is underlined.

Sperm duct, Seminiferous tubule, Epididymis, Efferent ducts.

Read the explanation given below and name the structure:

The canal through which the testes descend down into the scrotum just before the birth of a male baby.

Read the explanation given below and name the structure:

The part of the brain that regulates the peristaltic movement of the alimentary canal.

Read the explanation given below and name the structure:

A structure that collects the soundwaves and conducts them through the external auditory canal.

Read the explanation given below and name the structure:

The point of attachment of two chromatids of a chromosome.

Read the explanation given below and name the structure:

Regulation of the opening and closing of stomata.

Given below is an outline of the human body showing the important endocrine glands. Match the glands marked (a) to (e) with their correct functions:

Endocrine glands	Functions
	1. Prepares the body to face stress
	2. Secretes tropic hormones
	3. Secretes Oestrogens
	4. Maintains blood sugar level
	5. Regulates basal metabolism
	6. Secretes Testosterone

Write the overall chemical equation for photosynthesis.

Ramesh is a farmer who has a vineyard and cultivates grapes. To improve the shape of the grapes and make them elongated he sprays a particular phytohormone at the time of fruiting.

1. Name the phytohormone that Ramesh sprays on the plant at the time of fruiting.
2. These grapes are said to be seedless. What is the technical term for the formation of such fruits?

Mention the two rafts of nitrogenous bases which pair with each other with hydrogen bonds.

State any two disadvantages of living close to an airport.

Draw a neat, labelled diagram of an animal cell showing Metaphase with four chromosomes.

What is the structure of DNA as proposed by Watson and Crick?

Name the white blood cells that show phagocytosis.

Complete the food chain by mentioning the names of the organisms in (c) and (d):

State two harmful effects of acid rain on the environment.

Given below is a picture of a tree. Mention the scientific phenomena occurring in the parts labelled (a), (b) and (c).

What is micturition?

What is biomedical waste?

Give an example of biomedical waste.

Differentiate between the functions of Urethra and Uterus.

Rachna is an expert gymnast on the balance beam. She has been vigorously practising for the Olympic Games. Lately, she has been experiencing dizziness and losing her balance during the practise sessions.

1. Which part of the membranous labyrinth is responsible for maintaining the body balance on the beam?
2. Which type of balance is maintained by the structure mentioned in (a)?

Draw a neat and well-labeled diagram of the apparatus you would set up to show that oxygen is given out during photosynthesis.

Where are Hydathodes located?

What are vestigial organs?

Give one example of a vestigial structure in the human mouth.

Ahmed had a severe throat infection. After a few days he developed an earache too. What could be the reason for the pain in his ears? Explain.

Mr. Sharma is a 76 year old man. His vision was gradually becoming blurred. He consulted an eye doctor and it was diagnosed as cataract.

1. Which part of the eye does cataract affect?
2. Why does the vision become blurred?

Given below is the diagram of a plasmolysed cortical cell of a root.

Copy the diagram and label the following parts in the diagram:

1. Cytoplasm
2. Hypertonic solution
3. Plasma membrane

Define the following:

Allele

In the last century, the human population has increased tremendously. Death rate has reduced and life expectancy has increased. This rapid growth has placed significant pressure on resources. Global cooperation is needed for environmental preservation.

1. Mention any one reason for reduction in the death rate.
2. Name any one resource that is under pressure due to population explosion.

Give two functions of the amniotic fluid.

Expand CFC.

Expand the following:

CNG

Vineet’s day begins with a cup of piping hot coffee. Caffeine is a stimulant present in coffee which increases the circulation of Adrenaline in the body. Vineet feels refreshed, alert and focussed.

1. Name the organ that is stimulated by caffeine which makes Vineet alert and focussed.
2. Give the collective term for the protective membranes of the organ mentioned in (a).
3. Which part of the autonomic nervous system increases the secretion of Adrenaline?

Explain the term Excretion.

State the difference between Nephron and Neuron.

Mention any two objectives of ‘Swachh Bharat Abhiyan.’

Give two characteristic features of Cro-Magnon man.

1. Explain the phenotype of the offsprings of the F₁ generation obtained from the initial cross.
2. Mention the phenotypic ratio of the F₂ generation offsprings
3. State Mendel’s Law of Independent Assortment.