Sunday, February 1, 2026

The Nineteenth Century 1815-1914 Class 10 | Making of Global World Notes + PYQ [PDF].

The Nineteenth Century 1815-1914  

INTRODUCTION:

The nineteenth century brought dramatic changes to the world economy and society. Economic, political, social, cultural, and technological factors worked together to reshape how countries traded, how people migrated for work, and how capital moved across borders. This section explores how a global economy took shape during 1815-1914, driven by Britain's food needs, technological advances like railways and steamships, the darker side of colonialism, and the large-scale migration of Indian indentured labourers.

 

The Nineteenth Century 1815-1914 Class 10


Three types of economic flows

Economists identify three main types of movement in international economic exchanges during this period:

1.   Flow of trade – mainly trade in goods like cloth, wheat, cotton

2.   Flow of labour – migration of people searching for employment

3.   Flow of capital – movement of money for investments over long distances

All three flows were closely connected and affected people's lives more deeply than ever before.

Class 10 Science – Chapter: How Do Organisms Reproduce?


A World Economy Takes Shape

Britain's food problem

In the nineteenth century, Britain faced a dilemma: should it grow its own food or import it? Population growth from the late eighteenth century increased demand for food grains, and as cities expanded and industries grew, food prices rose.

Under pressure from landowners, the British government restricted corn (grain) imports through laws called the Corn Laws. Industrialists and urban workers were unhappy with high food prices and forced the government to abolish the Corn Laws.

What happened after Corn Laws were scrapped?

After the Corn Laws were removed, food could be imported into Britain more cheaply than it could be produced within the country. British agriculture could not compete with imports, so vast areas of land were left uncultivated and thousands of workers lost their jobs. Many flocked to cities or migrated overseas.

As food prices fell, consumption in Britain rose. From the mid-nineteenth century, faster industrial growth also led to higher incomes, which meant more food imports.

Global response to British demand

Around the world—in Eastern Europe, Russia, America, and Australia—lands were cleared and food production expanded to meet British demand.

But it was not just about clearing land. Railways were needed to link farms to ports, new harbours had to be built, and people had to settle on these lands. All these activities required capital (which flowed from financial centres like London) and labour (which led to migration).

Mass migration

Nearly 50 million people emigrated from Europe to America and Australia in the nineteenth century. Worldwide, an estimated 150 million people left their homes and crossed oceans in search of better lives.

Chapter 3: The Making of a Global World — NCERT


Role of Technology

Why technology mattered

Technological advances like railways, steamships, and the telegraph transformed the nineteenth-century world. But these technologies were often driven by larger social, political, and economic needs—especially colonization, which stimulated new investments in faster and cheaper transport.

Example: The meat trade

Until the 1870s, animals were shipped alive from America to Europe and slaughtered on arrival. But live animals took up ship space, many died during the voyage, and meat remained an expensive luxury.

The development of refrigerated ships changed everything. Now animals could be slaughtered in America, Australia, or New Zealand and transported to Europe as frozen meat. This reduced costs and lowered meat prices, allowing Europe's poor to add meat, butter, and eggs to their previously monotonous diet of bread and potatoes.

Better living conditions created social peace within European countries and increased support for imperialism abroad.

Class 10 Science – Chapter 6: Control and Coordination


Late Nineteenth-Century Colonialism

The darker side

The nineteenth century was not only about expanding trade and prosperity. In many parts of the world, closer ties to the global economy meant loss of freedoms and livelihoods. Late-nineteenth-century European conquests brought painful economic, social, and ecological changes to colonized societies.

Carving up Africa

In 1885, major European powers met in Berlin to divide Africa among themselves. Britain, France, Belgium, and Germany became colonial powers, and the US also took colonies from Spain in the late 1890s.

Section: THE SENSE OF COLLECTIVE BELONGING (Chapter 2: Nationalism in India — NCERT)


Rinderpest, or the Cattle Plague

What was Rinderpest?

Rinderpest was a devastating cattle disease that arrived in Africa in the late 1880s. It was carried by infected cattle imported from British Asia to feed Italian soldiers invading Eritrea in East Africa.

How it spread

Entering Africa from the east, Rinderpest moved west "like forest fire," reaching Africa's Atlantic coast by 1892 and the southern tip (Cape) by 1897. Along the way, it killed 90 percent of the cattle.

Impact on African livelihoods

Historically, Africa had abundant land and a small population. Africans sustained themselves through land and livestock and rarely worked for wages. Europeans who came to Africa to establish plantations and mines faced a labour shortage because Africans saw no reason to work for wages when they had enough land and cattle.

Employers used many methods to force Africans into wage labour: heavy taxes (payable only through wages), inheritance laws that displaced peasants from land, and confinement of mineworkers in compounds.

The loss of cattle due to Rinderpest destroyed African livelihoods. Planters, mine owners, and colonial governments monopolized the remaining cattle and forced Africans into the labour market. Control over scarce cattle resources enabled European colonizers to conquer and subdue Africa.

Class 10 Students (Board Exam 2026)! Chapter 6 Life Processes complete notes.


Indentured Labour Migration from India

What was indentured labour?

In the nineteenth century, hundreds of thousands of Indian and Chinese labourers went to work on plantations, in mines, and in construction projects around the world. Indian indentured workers were hired under contracts that promised return travel to India after five years of work.

Where did they come from?

Most Indian indentured workers came from present-day eastern Uttar Pradesh, Bihar, central India, and dry districts of Tamil Nadu. In the mid-nineteenth century, these regions experienced cottage industry decline, rising land rents, and land clearance for mines and plantations. Poor people failed to pay rents, became indebted, and were forced to migrate.

Where did they go?

Main destinations were the Caribbean islands (Trinidad, Guyana, Surinam), Mauritius, and Fiji. Tamil migrants went to Ceylon and Malaya, and workers were also recruited for tea plantations in Assam.

How were they recruited?

Recruitment was done by agents who were paid commissions. Many migrants hoped to escape poverty, but agents often provided false information about destinations, work, and living conditions. Some migrants were even forcibly abducted.

Living and working conditions

On arrival, labourers found conditions harsh, with few legal rights. Nineteenth-century indenture has been called a "new system of slavery."

But workers found their own ways of surviving: some escaped (though they faced severe punishment if caught), and others created new forms of cultural expression blending old and new traditions. In Trinidad, the Muharram procession became a carnival called "Hosay" where workers of all races joined. Rastafarianism and "chutney music" are other examples of cultural fusion born from the indenture experience.

Most indentured workers stayed on after contracts ended, creating large communities of people of Indian descent in these countries (like Nobel Prize-winner V.S. Naipaul and cricketers Shivnarine Chanderpaul and Ramnaresh Sarwan).

From the 1900s, India's nationalist leaders opposed indenture as abusive and cruel, and it was abolished in 1921.

Class 10 Students (Board Exam 2026)! Chapter 4 Carbon and its Compounds


Indian Entrepreneurs Abroad

Bankers and traders

Indian bankers like the Shikaripuri Shroffs and Nattukottai Chettiars financed export agriculture in Central and Southeast Asia using their own funds or money borrowed from European banks. They had sophisticated systems for transferring money over long distances.

Indian traders and moneylenders also followed European colonizers into Africa. Hyderabadi Sindhi traders established trading emporia at busy ports worldwide, selling local and imported goods to growing numbers of tourists.

Chapter 3 Metals & Non-metals 


Indian Trade, Colonialism and the Global System

Decline of Indian cotton exports

Historically, fine Indian cottons were exported to Europe. But with British industrialization, the government imposed tariffs on cloth imports to protect local industries, and the inflow of Indian cotton began to decline.

From the early nineteenth century, British manufacturers sought overseas markets. Indian cotton textile exports dropped from 30 percent around 1800 to 15 percent by 1815, and below 3 percent by the 1870s.

What did India export instead?

While manufactured exports declined, raw material exports increased rapidly. Between 1812 and 1871, raw cotton exports rose from 5 percent to 35 percent. Indigo (used for dyeing cloth) and opium (exported to China) were also major exports.

Britain's trade surplus with India

British exports to India were much higher in value than British imports from India, giving Britain a trade surplus with India. Britain used this surplus to balance its trade deficits with other countries—a system called multilateral settlement.

India's trade surplus also helped Britain pay "home charges" (remittances by British officials, interest on India's debt, and pensions). Thus, India played a crucial role in the late-nineteenth-century world economy.

Class 10 History (NCERT) Chapter 2 — Section 2: Differing Strands within the Movement


MCQs PYQ

 

1.   The Corn Laws in Britain restricted the import of:
A. Textiles
B. Food grains
C. Coal
D. Machinery
Answer: B

2.   After the Corn Laws were abolished, British agriculture:
A. Expanded rapidly
B. Could not compete with cheap imports
C. Became more profitable
D. Stopped completely
Answer: B

3.   Refrigerated ships were important because they:
A. Made voyages faster
B. Allowed transport of perishable food like meat over long distances
C. Reduced ship size
D. Stopped diseases
Answer: B

4.   Rinderpest entered Africa in the:
A. 1850s
B. Late 1880s
C. 1920s
D. 1950s
Answer: B

5.   Rinderpest killed what percentage of African cattle?
A. 50%
B. 70%
C. 90%
D. 100%
Answer: C

6.   Indentured labour from India mainly went to:
A. Europe and America
B. Caribbean, Mauritius, Fiji
C. China and Japan
D. Africa only
Answer: B

7.   The indentured labour system was abolished in:
A. 1857
B. 1905
C. 1921
D. 1947
Answer: C

8.   Indian cotton textile exports declined because:
A. India stopped production
B. British imposed tariffs and industrialized
C. There was no demand
D. All cotton was used domestically
Answer: B

9.   Britain used its trade surplus with India to:
A. Invest in Indian industries
B. Balance deficits with other countries
C. Stop all imports
D. Reduce Indian exports
Answer: B

10.                 The Shikaripuri Shroffs and Nattukottai Chettiars were:
A. British officials
B. Indian bankers and traders who financed export agriculture
C. African tribal leaders
D. European industrialists
Answer: B

Chapter 2: Acids, Bases & Salts. 



Short Answer Questions (PYQ)

 

Q1. What were the Corn Laws? Why were they abolished?

Answer: The Corn Laws restricted food grain imports into Britain to protect local landowners. They were abolished because industrialists and urban workers were unhappy with high food prices caused by these restrictions. After abolition, food could be imported cheaply, benefiting consumers but hurting British farmers.

Q2. How did technology help expand nineteenth-century trade?

Answer: Railways, steamships, and telegraph made transport faster and cheaper, helping move food and goods over long distances. Refrigerated ships allowed perishable foods like meat to be transported, lowering prices and increasing consumption. Colonization also stimulated investment in these technologies.

Q3. What was Rinderpest? How did it affect Africa?

Answer: Rinderpest was a cattle disease that arrived in Africa in the late 1880s and killed 90 percent of the cattle. This destroyed African livelihoods because Africans depended on livestock. European colonizers then monopolized remaining cattle and forced Africans into wage labour on plantations and mines.

Q4. Why did indentured labourers migrate from India?

Answer: Most came from regions experiencing cottage industry decline, rising rents, and land clearance for plantations and mines. Poor people became indebted and migrated hoping to escape poverty. Recruitment agents also tempted or forcibly took workers by providing false information about work and destinations.

Q5. How did India's role in global trade change in the nineteenth century?

Answer: Indian cotton textile exports declined sharply due to British tariffs and industrialization. India began exporting raw materials like raw cotton, indigo, and opium instead. Britain's trade surplus with India helped balance Britain's deficits with other countries, making India crucial to the global economy.

Class 10 Science Chapter-1: Chemical Reactions and Equations.


Long Answer Questions (PYQ)

 

Q1. Explain how a global agricultural economy developed in the nineteenth century.

Answer: Britain's population growth increased food demand, but the Corn Laws kept prices high by restricting imports. After the Corn Laws were abolished, cheap food imports made British agriculture uncompetitive, and workers lost jobs and migrated overseas. To meet British demand, lands were cleared for agriculture in Eastern Europe, Russia, America, and Australia. Railways were built to link farms to ports, which required capital (from London) and labour (through migration). Nearly 50 million Europeans migrated, and by 1890 a global agricultural economy had emerged, with food traveling thousands of miles and being grown by migrant workers on large farms.

Q2. Discuss the impact of Rinderpest on Africa and its people.

Answer: Rinderpest was a cattle disease that arrived in Africa in the late 1880s through infected cattle imported to feed Italian soldiers. It spread rapidly across Africa and killed 90 percent of the cattle by the late 1890s. This destroyed African livelihoods because Africans depended on land and livestock and rarely worked for wages. European colonizers monopolized the remaining scarce cattle resources and used heavy taxes, changed inheritance laws, and confined workers to force Africans into wage labour on plantations and mines. Control over cattle enabled Europeans to conquer and subdue Africa, showing the destructive impact of colonialism.

Q3. Describe the system of indentured labour migration from India. What were the living and working conditions?

Answer: In the nineteenth century, hundreds of thousands of Indians migrated as indentured labourers to Caribbean islands, Mauritius, Fiji, Ceylon, and Malaya under contracts promising return after five years. Most came from eastern UP, Bihar, central India, and Tamil Nadu, where cottage industries declined, rents rose, and people became indebted. Recruitment agents tempted or forcibly abducted workers using false information. On arrival, conditions were harsh with few legal rights, and the system has been called "new slavery." Workers survived by escaping (risking punishment) or creating new cultural forms like "Hosay" carnival and chutney music, blending different traditions.


Conclusion

The nineteenth century saw the emergence of a truly global economy driven by trade, labour migration, and capital flows. Britain's food needs reshaped agriculture worldwide, new technologies like railways and refrigerated ships transformed trade, but colonialism also brought suffering through conquest, forced labour, and diseases like Rinderpest. India played a crucial role by exporting raw materials and providing indentured labour, while also helping Britain balance its global trade through surplus earnings. For board exams, focus on examples like Corn Laws, Rinderpest, indentured labour, and India's changing trade patterns—these are frequently tested.


Download Class 10 Social Science Notes PDF

Looking for class 10 Social Science notes PDF download or class 10 The Nineteenth Century (1815-1914) notes PDF? This complete guide covers all topics from Chapter 3 with NCERT-based explanations, making it perfect for your CBSE Board 2026 preparation.

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·       Complete NCERT syllabus coverage

·       MCQs with answers

·       Short and long questions

·       Exam-focused content

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Wednesday, January 28, 2026

How Do Organisms Reproduce (Reproduction) Class 10 Complete Notes & MCQs [PDF].

How Do Organisms Reproduce 

INTRODUCTION:

How Do Organisms Reproduce? is one of those Class 10 Biology chapters that feels long at first, but becomes very easy once you see the pattern: one set of methods for asexual reproduction, one clear process for sexual reproduction in plants, and a fixed set of diagrams and steps for human reproduction. This chapter repeatedly appears in the board paper through “differentiate between…”, “draw and label…”, and “explain the process…” type questions, so it’s a high-return chapter for your time. In this blog, we’ll build the concepts from the basics—DNA copying and variation—then cover every asexual method with examples, pollination-to-fruit formation in flowering plants, and the complete human reproductive system (fertilization, placenta, menstrual cycle, contraception, and sex determination) in a clean, exam-ready format.


What is reproduction?

Reproduction is the biological process by which organisms produce new individuals of their own kind, ensuring continuity of species and maintaining population stability.

Why is reproduction important?

·       Ensures existence and continuity of species

·       Passes genetic information (DNA) to next generation

·       Creates variations which form the basis of evolution

DNA copying in reproduction

Before any organism reproduces, its DNA (genetic material) must be copied so that the new organism gets the same information. DNA copying is not 100% accurate—small variations occur during the process, which creates diversity and helps species adapt to changing environments.

Importance of DNA copying:

·       Ensures transfer of specific body design features to offspring

·       Creates variations helpful for survival

·       Maintains species continuity

Types of reproduction

Feature

Asexual reproduction

Sexual reproduction

Number of parents

One

Two (male and female)

Gamete formation

No gametes formed

Gametes (sex cells) formed

Fertilization

Does not occur

Fusion of male and female gametes

Genetic variation

Minimal (only from DNA copying errors)

High (combination of two parents' DNA)

Speed

Fast

Slower

Examples

Bacteria, Amoeba, Hydra, potato

Most animals, flowering plants, humans


Asexual reproduction

Asexual reproduction involves only one parent and produces offspring genetically identical (clones) to the parent.

 

Fission

Division of parent organism into two or more daughter cells.

Binary fission: Parent divides into TWO daughter cells

·       Amoeba: Can divide in any plane

·       Paramecium: Divides transversely (across the body)

·       Leishmania (causes Kala-azar): Divides longitudinally (along the flagellum)

Multiple fission: Parent divides into MANY daughter cells at once

·       Plasmodium (malaria parasite): Nucleus divides many times, then cytoplasm divides to form many daughter cells simultaneously

Budding

A small outgrowth (bud) develops on parent body, grows, and detaches to form new individual.

Example: Hydra, Yeast

Process in Hydra:

1.   Small bulge appears on parent body

2.   Bud develops mouth, tentacles (miniature Hydra)

3.   Bud detaches and becomes independent organism

Fragmentation

Organism breaks into two or more fragments; each fragment grows into complete organism.

Example: Spirogyra (algae)

When mature Spirogyra filament grows too long, it simply breaks into smaller fragments, and each fragment grows into new Spirogyra.

Regeneration

Ability of an organism to develop complete organism from broken body parts.

Example: Planaria, Hydra

If Planaria is cut into pieces, each piece regenerates missing parts (head, tail) and grows into complete Planaria. This happens because specialized cells proliferate and differentiate into different cell types.

Note: Regeneration is different from reproduction—it's primarily a survival mechanism, not a method of producing multiple offspring.

Spore formation

Organism produces tiny reproductive units called spores in structures called sporangia.

Example: Rhizopus (bread mould), ferns, mosses

Process in Rhizopus:

1.   Thread-like structures (hyphae) grow from fungus

2.   Blob-like structures (sporangia) develop at tips of hyphae

3.   Inside sporangia, nucleus divides many times to form spores

4.   Sporangia burst, releasing spores into air

5.   Spores land on moist surface and germinate into new Rhizopus

Advantages of spores:

·       Covered by thick protective wall (survives harsh conditions)

·       Light and small (easy dispersal by wind, water, animals)

Vegetative propagation

New plants grow from vegetative parts (roots, stems, leaves) without seeds.

Natural vegetative propagation examples:

·       Potato, ginger: New plants from underground stems (tubers, rhizomes)

·       Bryophyllum: Buds on leaf margins fall and grow into new plants

·       Sugarcane, rose, grapes: Stem cuttings grow into new plants

Artificial vegetative propagation methods:

·       Cutting: Cut stem/root planted in soil grows into new plant

·       Layering: Stem bent and buried; develops roots while attached to parent

·       Grafting: Parts of two different plants joined to grow as one (useful for fruit trees)

Table: Advantages and disadvantages of vegetative propagation

Advantages

Disadvantages

Faster than growing from seeds

Plants have less vigor, more prone to diseases

Retains exact characteristics of parent (good varieties preserved)

No genetic variation (all offspring identical)

Can grow seedless plants (banana, grapes, orange)

Requires more care and resources

Produces flowers/fruits in shorter time

Cannot adapt to changing environment

 History Class 10 Chapter 3: The Making of a Global World — NCERT


Sexual reproduction

Sexual reproduction involves two parents (male and female); their gametes (sex cells) fuse to form a zygote which develops into offspring with characteristics from both parents.

Why is sexual reproduction better for survival?

Sexual reproduction creates variations by combining DNA from two different individuals. These variations increase chances of survival in changing environments because some individuals may have traits suited to new conditions.

Class 10 Science – Chapter 6: Control and Coordination


Sexual reproduction in flowering plants

Structure of flower

Parts of flower:

Part

Type

Function

Sepals (Calyx)

Accessory

Protect flower bud

Petals (Corolla)

Accessory

Attract pollinators (insects, birds)

Stamens (Androecium)

Male reproductive part

Produce pollen grains (male gametes)

Carpel/Pistil (Gynoecium)

Female reproductive part

Contains ovules (female gametes)

Stamen parts: Anther (produces pollen) + Filament (stalk)

Carpel parts: Stigma (receives pollen) + Style (tube connecting stigma to ovary) + Ovary (contains ovules)

Unisexual flower: Has either stamens OR carpel (e.g., papaya, watermelon)

Bisexual flower: Has both stamens AND carpel (e.g., hibiscus, mustard)

Pollination

Pollination is the transfer of pollen grains from anther to stigma.

Type

Definition

Agents

Example

Self-pollination

Pollen transfer within same flower or between flowers of same plant

Wind, gravity

Pea, wheat

Cross-pollination

Pollen transfer between flowers of two different plants of same species

Wind, water, insects, birds

Maize, papaya

 

Why is cross-pollination better? It brings genetic material from two different plants, creating variations that help species survive. Self-pollination produces genetically uniform offspring.

 

Fertilization in plants

Steps after pollination:

1.   Pollen grain lands on stigma

2.   Pollen grain germinates, forms pollen tube that grows down through style

3.   Pollen tube reaches ovule in ovary

4.   Male gamete from pollen tube fuses with female gamete (egg) in ovule Fertilization

5.   Fertilized egg becomes zygote

6.   Zygote divides repeatedly to form embryo

7.   Ovule develops into seed (contains embryo + stored food)

8.   Ovary develops into fruit (protects seeds)

THE SENSE OF COLLECTIVE BELONGING (Chapter 2: Nationalism in India — NCERT) 


Sexual reproduction in human beings

Male reproductive system

Main organs and functions:

Organ

Function

Testes (pair)

Produce sperms (male gametes) and testosterone hormone

Scrotum

Pouch holding testes outside body (keeps temperature 2-3°C lower for sperm production)

Vas deferens

Tube carrying sperms from testes

Seminal vesicles, Prostate gland, Cowper's gland

Secrete fluids that nourish sperms and make transport easier (together = semen)

Urethra

Common passage for sperms and urine (exits through penis)

Penis

Transfers sperms into female vagina during sexual act

 

Sperm: Has 23 chromosomes (either X or Y chromosome)

 

Female reproductive system

Main organs and functions:

Organ

Function

Ovaries (pair)

Produce eggs (ova/female gametes) and hormones (estrogen, progesterone)

Fallopian tubes/Oviducts (pair)

Site of fertilization; transport egg from ovary to uterus by ciliary action

Uterus

Muscular bag where embryo implants and develops during pregnancy

Cervix

Narrow opening of uterus into vagina

Vagina

Receives sperms during sexual act; birth canal during delivery

Egg: Has 23 chromosomes (always X chromosome)

 

Fertilization and development

Process:

1.   Ovulation: One egg released from ovary every month (around day 14 of menstrual cycle)

2.   Egg enters fallopian tube

3.   If sexual intercourse occurs, sperms deposited in vagina travel through uterus to fallopian tube

4.   One sperm fuses with egg Fertilization Forms zygote (46 chromosomes)

5.   Zygote divides repeatedly while moving toward uterus

6.   Implantation: Developing embryo (blastocyst) attaches to thick, soft uterine wall

Placenta

Placenta is a disc-shaped structure embedded in uterine wall that connects developing embryo to mother.

Functions of placenta:

·       Provides nutrition (glucose, amino acids) from mother's blood to fetus

·       Provides oxygen to fetus

·       Removes waste products (CO, urea) from fetus to mother's blood

·       Acts as barrier (prevents mixing of mother's and fetus blood)

Development timeline:

·       Embryo develops all body parts by 8 weeks

·       After 8 weeks, called fetus

·       Full development takes about 9 months (280 days)

·       Birth occurs through vagina

Menstrual cycle

Menstruation is the monthly cycle in sexually mature females where uterus prepares for pregnancy.

Cycle (28 days average):

1.   Day 1-5: Menstrual flow (shedding of uterine lining because no fertilization occurred)

2.   Day 6-13: Uterine lining thickens again; egg matures in ovary

3.   Day 14: Ovulation (egg released)

4.   Day 15-28: If fertilization occurs pregnancy; if not cycle repeats from day 1

Age range: Begins at puberty (10-12 years), stops at menopause (45-50 years)

Reproductive health and contraception

Why contraception? Control birth rate, prevent unwanted pregnancies, prevent sexually transmitted diseases (STDs).

Contraceptive methods:


 

 

Method

How it works

Examples

 

Barrier methods

Prevent sperm from reaching egg

Condoms (male/female), diaphragm, cervical cap

 

Chemical methods

Change hormonal balance to prevent ovulation

Oral pills, vaginal pills, IUDs

 

Surgical methods

Permanently block gamete transport

Vasectomy (males - block vas deferens), Tubectomy (females - block fallopian tubes)





 Class 10 Students (Board Exam 2026)! Chapter 6 Life Processes complete notes


Sex determination in humans

Humans have 23 pairs of chromosomes (46 total). Pair 23 are sex chromosomes.

·       Females: XX (both sex chromosomes are X)

·       Males: XY (one X, one Y chromosome)

How sex is determined:

·       Mother always gives X chromosome (her eggs have only X)

·       Father gives either X or Y chromosome (50% sperms have X, 50% have Y)

·       If sperm with X fertilizes egg XX Girl child

·       If sperm with Y fertilizes egg XY Boy child

Conclusion: Father's chromosome determines sex of child.

Class 10 Students (Board Exam 2026)! Chapter 4 Carbon and its Compounds 


MCQs PYQ

 

Q1. Sexual reproduction involves:
(a) Two parents
(b) One parent
(c) Gamete formation
(d) Fertilization
Answer: (b) One parent. (CBSE 2020)


Q2.
The causative agent of Kala-azar reproduces by:
(a) Binary fission
(b) Multiple fission
(c) Budding
(d) Fragmentation
Answer: (a) Leishmania reproduces by binary fission. (CBSE 2015)


Q3.
Vegetative propagation in Bryophyllum occurs by:
(a) Stem
(b) Root
(c) Leaf
(d) Flower
Answer: (c) Buds on leaf margins. (CBSE 2016)


Q4.
The part of flower that becomes fruit after fertilization:
(a) Ovule
(b) Ovary
(c) Stigma
(d) Style
Answer: (b) Ovary becomes fruit. (CBSE 2020)


Q5.
Fertilization in humans occurs in:
(a) Ovary
(b) Uterus
(c) Fallopian tube
(d) Vagina
Answer: (c) Fallopian tube. (CBSE 2024)


Q6.
The chromosome responsible for male child is:
(a) X from mother
(b) X from father
(c) Y from mother
(d) Y from father
Answer: (d) Y from father. (CBSE 2023)


Q7.
Spores are covered by thick walls because:
(a) To attract pollinators
(b) To survive unfavorable conditions
(c) For nutrition
(d) For photosynthesis
Answer: (b) Thick wall protects spores in harsh environments. (CBSE 2020)


Q8.
Cross-pollination is better than self-pollination because:
(a) It is faster
(b) It creates variations
(c) It needs no agents
(d) It produces more seeds
Answer: (b) Creates genetic variations. (CBSE 2021)


Q9.
Placenta functions as:
(a) Only nutritive organ
(b) Only respiratory organ
(c) Nutritive, respiratory and excretory organ
(d) Only excretory organ
Answer: (c) All three functions. (CBSE 2024)


Q10.
Binary fission in Amoeba differs from Leishmania in:
(a) Number of daughter cells
(b) Plane of division
(c) Speed
(d) DNA copying
Answer: (b) Amoeba divides in any plane; Leishmania divides longitudinally.
(CBSE 2020)

Class 10 Students (Board 2026)! Chapter 3 Metals & Non-metals


Short Answer Questions (PYQ)

 

Q1. What is DNA copying? Why is it important in reproduction?
Answer: DNA copying is the process of creating identical copies of DNA using chemical reactions. It ensures genetic information is passed to offspring and creates minor variations helpful for evolution. (CBSE 2015)


Q2. Differentiate between binary fission and multiple fission.

Answer: Binary fission: parent divides into two daughter cells (e.g., Amoeba). Multiple fission: parent divides into many daughter cells simultaneously (e.g., Plasmodium). (CBSE 2015)


Q3. Why is vegetative propagation useful for farmers?

Answer: It preserves good characteristics of parent plant, produces plants faster than seeds, and can grow seedless plants like banana, grapes, sugarcane. (CBSE 2014)


Q4. What is pollination? Why is cross-pollination better?

Answer: Transfer of pollen from anther to stigma. Cross-pollination brings genetic material from two different plants, creating variations that improve species survival. (CBSE 2020)


Q5. List two functions of ovary in human females.

Answer: (1) Produces eggs (ova), (2) Secretes female hormones estrogen and progesterone. (CBSE 2016)

Class 10 History (NCERT) Chapter 2 — Section 2: Differing Strands within the Movement


Long Answer Questions (PYQ)

 

Q1. Explain regeneration in Planaria. How is it different from reproduction?

Answer: When Planaria is cut into pieces, each piece regenerates missing parts through cell division and differentiation. Difference: Reproduction produces new organisms from complete parent; regeneration is survival mechanism where body parts regrow. (CBSE 2015, 2014)

Q2. Describe spore formation in Rhizopus with diagram (in words).

Answer: Thread-like hyphae grow Blob-like sporangia form at tips Nucleus divides many times inside sporangia forming spores Sporangia burst, release spores Spores land on moist surface and germinate into new Rhizopus. (CBSE 2017)

Q3. How is sex determined in humans? Why are males responsible?

Answer: Humans have 22 pairs of autosomes + 1 pair of sex chromosomes. Females: XX; Males: XY. Mother always gives X; father gives X (girl) or Y (boy). Father's sperm determines sex of child. (CBSE 2020)

Q4. Explain the process of fertilization and development in humans.

Answer: Ovulation egg in fallopian tube sperm meets egg fertilization zygote (46 chromosomes) zygote divides forming embryo implantation in uterus placenta forms embryo develops for 9 months baby born. (CBSE 2020)

Q5. Differentiate between self-pollination and cross-pollination. Which is better and why?

Answer: Self: pollen transfer within same flower/plant; no agent needed; less variation. Cross: pollen transfer between two plants; needs agents (wind, insects); high variation. Cross-pollination is better because variations help species adapt to changing environment and survive. (CBSE 2020)


Conclusion

How Do Organisms Reproduce becomes easy when you organize it into three parts: (1) Asexual reproduction methods (fission, budding, fragmentation, regeneration, spores, vegetative propagation—each with clear examples), (2) Sexual reproduction in plants (flower parts, pollination, fertilization leading to seed and fruit), and (3) Human reproduction (male/female reproductive systems, fertilization, placenta, menstruation, contraception, sex determination). NCERT emphasizes to learn comparison questions like "binary vs multiple fission," "asexual vs sexual," "self vs cross-pollination." Understanding reproductive health and contraception also scores easy marks. This chapter consistently gives 6-7 marks in Board Exams.


Download Class 10 Science Notes PDF

Looking for class 10 Science notes PDF download or class 7 How Do Organism Reproduce notes PDF? This complete guide covers all topics from Chapter 3 with NCERT-based explanations, making it perfect for your CBSE Board 2026 preparation.

Key Features of These Notes:

·       Easy language explanations

·       Complete NCERT syllabus coverage

·       MCQs with answers

·       Short and long questions

·       Exam-focused content

Download PDF: Click Here.


You now have complete NCERT-based notes on “How Do Organism Reproduce" in very simple English! For more NCERT-based Class 10 Science notes, exam tips, and study materials, bookmark this page and share with your friends. If you have doubts about any concept, comment below. All the best for your board exams!



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