Thomas Malthus
1766–1834
Thomas Malthus studied population growth. He explained how a rapidly growing population can increase pressure on food and other resources.
1766–1834
Thomas Malthus studied population growth. He explained how a rapidly growing population can increase pressure on food and other resources.
Chapter 14
Population and Natural Environment
Population and Natural Environment
Textual Dictionary
Every word below is taken from this chapter, and the meanings are given in English.
| Word (Pronunciation) | Meaning | Synonyms | Antonyms | Example Sentence |
|---|---|---|---|---|
| population (pop-yoo-LAY-shun) | The number of people living in a place. | people; inhabitants | — | The population of Bangladesh grew over time. The number of people in Bangladesh increased over time. |
| density (DEN-si-tee) | The number of people in a particular area. | concentration; thickness | sparseness; emptiness | Population density is found by dividing total population by total area. |
| resources (ree-SOR-siz) | Useful supplies provided by nature or available for use. | supplies; materials | waste; shortage | A growing population needs more natural resources. |
| shortage (SHOR-tij) | A condition in which there is not enough of something. | lack; scarcity | abundance; plenty | Population growth may cause a shortage of food and land. |
| pollution (puh-LOO-shun) | The harmful contamination of air, water, or soil. | contamination; dirt | cleanliness; purity | Excessive chemicals can cause soil pollution and water pollution. |
| renewable (ree-NOO-uh-bul) | Able to be replaced or used again naturally. | replaceable; reusable | non-renewable; limited | A solar panel uses a renewable resource to produce electricity. |
| extinction (ek-STINGK-shun) | The complete disappearance of a kind of living thing. | disappearance; destruction | survival; existence | The loss of forests can lead to the extinction of living things. |
Dictionary entries: 7
1. How to Use This Sheet
- Read the chapter before studying the vocabulary.
- Cover the meaning column and test yourself on each word.
- Read each example sentence carefully.
- Use the example sentences as models for your own writing practice.
- Review the synonyms and antonyms to strengthen your vocabulary.
- Use only the words taken from this chapter when completing the activities.
Textual Dictionary
| Word (Pronunciation) | Meaning | Synonyms | Antonyms | Example Sentence |
|---|---|---|---|---|
| population (pop-yoo-LAY-shun) | The number of people living in a place. | people; inhabitants | — | A growing population needs more food and land. A growing number of people needs more food and land. |
| density (DEN-si-tee) | The number of people per square kilometre of land. | concentration; thickness | sparseness; emptiness | High population density can make germs spread faster. In a densely populated place, germs may spread quickly. |
| resources (ree-SOR-siz) | Useful supplies provided by nature or available for use. | supplies; materials | waste; shortage | People must use natural resources carefully. People should use useful supplies from nature carefully. |
| shortage (SHOR-tij) | A condition in which there is not enough of something. | lack; scarcity | abundance; plenty | A shortage of land may create problems for growing families. A lack of land may create problems for growing families. |
| pollution (puh-LOO-shun) | The harmful contamination of air, water, or soil. | contamination; dirt | cleanliness; purity | Careless use of chemicals can increase water pollution. Chemicals used carelessly can make water harmful. |
| renewable (ree-NOO-uh-bul) | Able to be replaced or used again naturally. | replaceable; reusable | non-renewable; limited | Solar energy comes from a renewable resource. Solar energy comes from a resource that can be used naturally again. |
| extinction (ek-STINGK-shun) | The complete disappearance of a kind of living thing. | disappearance; destruction | survival; existence | The loss of forests may cause the extinction of living things. When forests disappear, some living things may disappear completely. |
Dictionary entries: 7
◆ Key Points
- Population means the number of people living in a place.
- Population density means the number of people per square kilometre of land.
- Population density is found by dividing the total population by the total area.
- As population grows, the need for food, water, shelter, clothing, and land increases.
- Growing human needs can put pressure on natural resources.
- Population growth may cause shortages of food, clothing, housing, and land.
- Germs can spread faster in denser populations.
- Clearing forests can change ecosystems, destroy habitats, and cause extinction.
- Excessive chemical fertilisers and pesticides can cause soil and water pollution.
- Burning fossil fuel can release harmful gases that cause air pollution, global warming, and acid rain.
- Science and technology can help produce more food and reduce the use of non-renewable resources.
- Solar panels use renewable resources, and hybrid cars can reduce the use of fossil fuel.
◆
2. Key Words - Main Table (1-15)
| Word (Pronunciation) | Meaning | Synonyms | Antonyms | Example Sentence |
|---|---|---|---|---|
| population (ˌpɒp.jəˈleɪ.ʃən) | The number of people living in a place. | people; inhabitants; residents | — | The population of Bangladesh was 14 crore 97 lac 72 thousand and 364 in 2011. This sentence gives the population at a particular time. |
| natural (ˈnætʃ.ər.əl) | Existing in nature or provided by nature. | native; environmental; organic | artificial; man-made | Growing human needs can put pressure on natural resources. Resources from nature must be used carefully. |
| environment (ɪnˈvaɪ.rən.mənt) | The surroundings in which people, animals, and plants live. | surroundings; ecosystem; habitat | — | Population growth has several impacts on the environment. Growth in population can change our surroundings. |
| increasing (ɪnˈkriː.sɪŋ) | Becoming greater in number or amount. | growing; rising; expanding | decreasing; falling; reducing | World human is increasing. The number of people in the world is becoming greater. |
| resources (rɪˈzɔːr.sɪz) | Useful supplies provided by nature or available for use. | supplies; materials; assets | waste; shortage; lack | We need more food, land and other natural resources for a growing population. A growing population needs more useful supplies. |
| growing (ˈɡrəʊ.ɪŋ) | Increasing in size, number, or amount. | developing; rising; increasing | shrinking; decreasing; reducing | People use agricultural machinery to grow a lot of food in the shortest period. Machines help people produce more food quickly. |
| problems (ˈprɒb.ləmz) | Difficult matters that need attention or a solution. | difficulties; troubles; issues | answers; solutions; advantages | What are the problems with population growth? The question asks about difficulties caused by population growth. |
| solutions (səˈluː.ʃənz) | Ways of solving problems. | answers; remedies; resolutions | problems; questions; difficulties | Do we have any solutions to these problems? The lesson asks how these difficulties can be solved. |
| resolve (rɪˈzɒlv) | To solve a problem or difficulty. | solve; settle; fix | create; worsen; complicate | How do we resolve these problems? The question asks how we can solve the difficulties. |
| growth (ɡrəʊθ) | An increase in size, number, or amount. | increase; rise; development | decline; decrease; reduction | Population growth may cause shortages of food, clothing, housing, and land. A larger population may create shortages. |
| density (ˈden.sə.ti) | The number of people per square kilometre of land area. | concentration; closeness; crowdedness | sparseness; emptiness; openness | Population density is the number of people per square kilometre land area. Density shows how many people live in a land area. |
| area (ˈeə.ri.ə) | The amount of surface covered by a place. | region; place; space | — | Population density can be found by dividing total population by total area of a country. The land area is used in calculating density. |
| country (ˈkʌn.tri) | A nation with its own land and government. | nation; state; land | — | Population density can be found by dividing total population by total area of a country. A country has a population and a total area. |
| high (haɪ) | Great in amount, level, or degree. | great; elevated; excessive | low; small; limited | Population density in Bangladesh is very high. Many people live within the land area. |
| needs (niːdz) | Things that are necessary for living or doing something. | requirements; necessities; demands | luxuries; extras; wants | The more population grows, the more human needs increase. A larger population requires more necessary things. |
◆ Key Points
- Population means the number of people living in a place.
- Population density means the number of people per square kilometre of land area.
- Population density is found by dividing total population by total area.
- A growing population needs more food, water, shelter, clothing, and land.
- Growing human needs can put pressure on natural resources.
- Population growth may cause shortages of food, clothing, housing, and land.
- Germs can spread faster in denser populations.
- Clearing forests can change ecosystems and destroy habitats.
- The loss of forests can cause the extinction of living things.
- Excessive chemical fertilisers and pesticides can cause soil and water pollution.
- Burning fossil fuel can cause air pollution, global warming, and acid rain.
- Science and technology can help produce more food and reduce the use of non-renewable resources.
3. Key Words - Main Table (16-30)
| Word (Pronunciation) | Meaning | Synonyms | Antonyms | Example Sentence |
|---|---|---|---|---|
| pressure (PRESH-er) | A force or demand that makes something difficult (a strong demand or force). | strain; stress; burden | relief; ease; comfort | Growing human needs can create pressure on natural resources. Growing needs can put a heavy demand on nature. |
| shortage (SHOR-tij) | A situation in which there is not enough of something (a lack of supply). | lack; scarcity; deficiency | abundance; plenty; surplus | Population growth may cause a shortage of land. A growing population may leave too little land. |
| shelter (SHEL-ter) | A place that provides protection or a home (a protected place to live). | housing; home; refuge | exposure; homelessness; openness | A growing population needs more shelter. More people need more protected homes. |
| clothing (KLOH-thing) | Things worn to cover and protect the body (items worn on the body). | clothes; garments; dress | — | Population growth may increase the need for clothing. More people may need more clothes. |
| diseases (di-ZEE-ziz) | Illnesses that affect people or other living things (health problems). | illnesses; sicknesses; ailments | health; wellness; fitness | Population growth can make people get diseases easily. A growing population may make illness spread more easily. |
| germs (JURMZ) | Very small organisms that can cause disease (disease-causing microorganisms). | microbes; organisms; pathogens | — | Germs can spread faster in denser populations. Disease-causing organisms may move quickly among many people. |
| medical (MED-i-kəl) | Related to the treatment or prevention of disease (connected with health care). | health; clinical; therapeutic | nonmedical; unhealthy; harmful | A growing population may have less chance of getting medical services. More people may have fewer opportunities for health services. |
| opportunities (op-er-TOO-ni-teez) | Chances to do or use something (available chances). | chances; possibilities; openings | barriers; obstacles; restrictions | Opportunities for using natural resources may get reduced. There may be fewer chances to use resources. |
| reduced (ri-DOOST) | Made smaller in amount or number (made less). | decreased; lowered; diminished | increased; enlarged; expanded | The opportunities for using natural resources may be reduced. The available chances may become fewer. |
| forests (FOR-ists) | Large areas covered mainly by trees (wooded areas). | woodlands; forests; groves | deserts; clearings; wastelands | People clear forests to cultivate more crops. People remove trees to grow more crops. |
| cultivate (KUL-ti-vayt) | To prepare land and grow crops (to farm plants). | farm; grow; plant | neglect; abandon; ignore | People clear forests to cultivate more crops. People clear wooded land so that crops can be grown. |
| livestock (LYVE-stok) | Farm animals kept for use or production (animals raised on farms). | farm animals; cattle; stock | wildlife; wild animals; pets | People clear forests to farm more livestock. People remove forests to raise more farm animals. |
| ecosystem (EE-koh-sis-təm) | A community of living things and their surroundings (living systems and their environment). | ecological system; habitat system; environment | — | The loss of forests causes changes in the ecosystem. When forests disappear, the living system can change. |
| habitats (HAB-i-tats) | The natural homes of living things (places where organisms live). | homes; environments; living places | — | The loss of forests causes the destruction of habitats. Removing forests destroys the natural homes of living things. |
| extinction (ek-STINGK-shən) | The complete disappearance of a kind of living thing (the end of a species). | disappearance; destruction; elimination | survival; existence; continuation | The loss of forests can cause the extinction of living things. Some living things may disappear completely. |
Dictionary entries: 15
◆Key Points
- Population growth can create pressure on natural resources.
- A shortage means that there is not enough of something.
- Food, water, shelter, clothing, and land are important human needs.
- Germs can spread faster when populations are denser.
- Medical services and education services may become less available as population grows.
- Clearing forests removes habitats and changes ecosystems.
- Excessive use of chemical fertilisers and pesticides can cause soil and water pollution.
- Science and technology can help produce more food for a growing population.
- Solar panels use renewable resources to produce electricity.
- Hybrid cars can reduce the use of fossil fuel.
4. Subject Terms and Definitions
| Word (Pronunciation) | Meaning | Synonyms | Antonyms | Example Sentence |
|---|---|---|---|---|
| population (pop-yoo-LAY-shun) | The number of people living in a place. | people; inhabitants; residents | — | The population of Bangladesh was 14 crore 97 lac 72 thousand and 364 as of 2011. |
| density (DEN-si-tee) | The number of people per square kilometre of land area. | concentration; closeness; crowdedness | sparseness; emptiness; openness | Population density in Bangladesh is very high. |
| resources (ree-SOR-siz) | Useful supplies provided by nature or available for use. | supplies; materials; assets | waste; shortage; lack | We need more food, land and other natural resources for growing population. |
| shortage (SHOR-tij) | A condition in which there is not enough of something. | lack; scarcity; deficiency | abundance; plenty; surplus | We will face the issue of a shortage of food, clothing, housing, and land when population grows. |
| ecosystem (EE-koh-sis-təm) | A system of living things and their surroundings. | ecological system; habitat system; environment | — | The loss of forests causes the changes of ecosystem. |
| habitats (HAB-i-tats) | The natural homes of living things. | homes; environments; living places | — | The loss of forests causes the destruction of habitats of living things. |
| extinction (ek-STINGK-shun) | The complete disappearance of a kind of living thing. | disappearance; destruction; elimination | survival; existence; continuation | The loss of forests causes the extinction of living things. |
| pollution (puh-LOO-shun) | Harmful contamination of the air, water, or soil. | contamination; dirt; impurity | cleanliness; purity; cleanness | Excessive use of chemical fertiliser and pesticide can cause soil pollution and water pollution. |
| renewable (ree-NOO-uh-bul) | Able to be replaced or used again naturally. | replaceable; reusable; restorable | non-renewable; limited; exhaustible | A solar panel uses renewable resources to produce electricity. |
| fossil fuel (FOS-il fyoo-əl) | A fuel used to produce energy that is not renewable. | fuel; energy source; non-renewable resource | renewable resource; clean energy; solar energy | Fossil fuel is burnt in power plants and factories to produce more electricity and goods. |
◆ Key Points
- Population means the number of people living in a place.
- Population density means the number of people per square kilometre of land area.
- Population density is found by dividing total population by total area.
- Growing populations need more food, water, shelter, clothing, and land.
- Growing human needs can create pressure on natural resources.
- A shortage occurs when there is not enough of something.
- Germs can spread faster in denser populations.
- Clearing forests can change ecosystems and destroy habitats.
- The destruction of habitats can cause the extinction of living things.
- Excessive chemical fertiliser and pesticide can cause soil and water pollution.
- Burning fossil fuel can cause air pollution, global warming, and acid rain.
- Science and technology can help produce more food and reduce the use of non-renewable resources.
- Solar panels use renewable resources to produce electricity.
5. Words in Context
Read the passage carefully. The bold words are taken from the chapter and are used in a connected context.
As the population grows, people need more food, land, water, and other natural resources. A high population density can affect the environment because people may clear forests for crops, roads, homes, and industries. The loss of forests can destroy habitats and may lead to the extinction of living things. Careless use of chemicals can cause pollution, while solar panels use a renewable resource. Reducing the use of fossil fuel can help protect the environment.
Use the table to understand how each word works in the chapter. Then read the example sentences aloud and use the words in your own sentences.
| Word (Pronunciation) | Meaning | Synonyms | Antonyms | Example Sentence |
|---|---|---|---|---|
| population (ˌpɒp.jəˈleɪ.ʃən) | The number of people living in a place. | people; inhabitants; residents | — | As the population grows, people need more food and land. |
| resources (rɪˈzɔːr.sɪz) | Useful supplies provided by nature or available for use. | supplies; materials; assets | waste; shortage; lack | Growing populations need more natural resources. |
| density (ˈden.sə.ti) | The number of people per square kilometre of land area. | concentration; closeness; crowdedness | sparseness; emptiness; openness | High population density can make germs spread faster. |
| environment (ɪnˈvaɪ.rən.mənt) | The surroundings in which people, animals, and plants live. | surroundings; ecosystem; habitat | — | Population growth has several impacts on the environment. |
| habitats (ˈhæb.ɪ.tæts) | The natural homes of living things. | homes; environments; living places | — | The loss of forests causes the destruction of habitats of living things. |
| extinction (ekˈstɪŋk.ʃən) | The complete disappearance of a kind of living thing. | disappearance; destruction; elimination | survival; existence; continuation | The loss of forests causes the extinction of living things. |
| pollution (pəˈluː.ʃən) | Harmful contamination of the air, water, or soil. | contamination; dirt; impurity | cleanliness; purity; cleanness | Excessive use of chemical fertiliser and pesticide can cause soil pollution and water pollution. |
| renewable (rɪˈnjuː.ə.bəl) | Able to be replaced or used again naturally. | replaceable; reusable; restorable | non-renewable; limited; exhaustible | A solar panel uses renewable resources to produce electricity. |
| fossil fuel (ˈfɒs.əl ˌfjuː.əl) | A fuel used to produce energy that is not renewable. | fuel; energy source; non-renewable resource | renewable resource; clean energy; solar energy | Burning fossil fuel can cause air pollution, global warming, and acid rain. |
6. Exercise 1 - Match the Meaning
Match each word with the correct meaning. Write the correct letter beside each word.
| Word (Pronunciation) | Meaning | Synonyms | Antonyms | Example Sentence |
|---|---|---|---|---|
| 1. population (pop-yoo-LAY-shun) | (A) The surroundings in which people, animals, and plants live. | people (মানুষ); inhabitants (বাসিন্দা); residents (অধিবাসী) | — | The population of Bangladesh was 14 crore 97 lac in 2011. |
| 2. density (DEN-si-tee) | (B) Able to be replaced or used again naturally. | concentration (ঘনত্ব); closeness (নিকটতা); crowdedness (ভিড়পূর্ণতা) | sparseness (বিরলতা); emptiness (শূন্যতা); openness (উন্মুক্ততা) | Population density in Bangladesh is very high. |
| 3. resources (ree-SOR-siz) | (C) A condition in which there is not enough of something. | supplies (সরবরাহ); materials (উপকরণ); assets (সম্পদ) | waste (অপচয়); shortage (ঘাটতি); lack (অভাব) | We need more food, land, and other natural resources. |
| 4. shortage (SHOR-tij) | (D) The number of people living in a place. | lack (অভাব); scarcity (দুর্লভতা); insufficiency (অপর্যাপ্ততা) | abundance (প্রাচুর্য); plenty (প্রাচুর্য); excess (অতিরিক্ততা) | Population growth may cause a shortage of food, clothing, housing, and land. |
| 5. pollution (puh-LOO-shun) | (E) The natural homes of living things. | contamination (দূষণ); dirt (ময়লা); impurity (অশুদ্ধতা) | cleanliness (পরিচ্ছন্নতা); purity (বিশুদ্ধতা); cleanness (নির্মলতা) | Excessive use of chemical fertiliser can cause soil pollution. |
| 6. renewable (ree-NOO-uh-bul) | (F) A fuel used to produce energy that is not renewable. | replaceable (পুনঃস্থাপনযোগ্য); reusable (পুনর্ব্যবহারযোগ্য); restorable (পুনরুদ্ধারযোগ্য) | non-renewable (অপুনর্নবীকরণযোগ্য); limited (সীমিত); exhaustible (নিঃশেষযোগ্য) | A solar panel uses renewable resources to produce electricity. |
| 7. extinction (ek-STINGK-shun) | (G) Harmful contamination of the air, water, or soil. | disappearance (অদৃশ্য হয়ে যাওয়া); destruction (ধ্বংস); elimination (বিলুপ্তি) | survival (বেঁচে থাকা); existence (অস্তিত্ব); continuation (ধারাবাহিকতা) | The loss of forests causes the extinction of living things. |
| 8. environment (in-VAI-ruhn-muhnt) | (H) The complete disappearance of a kind of living thing. | surroundings (পরিবেশ); ecosystem (বাস্তুতন্ত্র); habitat (আবাসস্থল) | — | Population growth has several impacts on the environment. |
| 9. habitats (HAB-i-tats) | (I) Useful supplies provided by nature or available for use. | homes (বাসস্থান); environments (পরিবেশ); living places (জীবের স্থান) | — | The loss of forests causes the destruction of habitats of living things. |
| 10. fossil fuel (FOS-uhl FYOO-uhl) | (J) The number of people per square kilometre of land area. | fuel (জ্বালানি); energy source (শক্তির উৎস); non-renewable resource (অপুনর্নবীকরণযোগ্য সম্পদ) | renewable resource (পুনর্নবীকরণযোগ্য সম্পদ); clean energy (পরিচ্ছন্ন শক্তি); solar energy (সৌরশক্তি) | Burning fossil fuel can cause air pollution, global warming, and acid rain. |
Answer Key: 1–D, 2–J, 3–I, 4–C, 5–G, 6–B, 7–H, 8–A, 9–E, 10–F
Worked Example Series
Ex. Find the increase in the world population from the early 1800s to today.
Sol: Increase = 700 crore − 100 crore
= 600 crore
= Ans. 600 crore
Ex. Find the increase in Bangladesh's population from the 1970s to 2011, using the given approximate figures.
Sol: Increase = 14 crore 97 lac − 7 crore 60 lac
= 7 crore 37 lac
= Ans. 7 crore 37 lac
Ex. Find the population density of Bangladesh in 2001. Population: 12 crore 93 lac; total area: 1,47,570 square kilometres.
Sol: Density = 12 crore 93 lac1,47,570
= 12,93,00,0001,47,570
≈ 876 people per square kilometre
= Ans. Approximately 876 people per square kilometre
Ex. Find the population density of Bangladesh in 1961. Population: 5 crore 52 lac; total area: 1,47,570 square kilometres.
Sol: Density = 5 crore 52 lac1,47,570
= 5,52,00,0001,47,570
≈ 374 people per square kilometre
= Ans. Approximately 374 people per square kilometre
7. Exercise 2 - Fill in the Blanks
Word Bank
population · density · resources · shortage · pollution · renewable · extinction · environment · habitats · fossil fuel
Fill in each blank with a suitable word from the word bank.
- The number of people living in a place is called the __________.
- Population __________ means the number of people per square kilometre of land area.
- Growing human needs can put pressure on natural __________.
- Population growth may cause a __________ of food, clothing, housing, and land.
- Excessive use of chemical fertiliser can cause soil and water __________.
- Solar panels use a __________ resource to produce electricity.
- The loss of forests can cause the __________ of living things.
- Population growth has several impacts on the __________.
- The loss of forests causes the destruction of __________ of living things.
- Burning __________ can cause air pollution, global warming, and acid rain.
Answer Key
- population
- density
- resources
- shortage
- pollution
- renewable
- extinction
- environment
- habitats
- fossil fuel
Textual Dictionary
| Word (Pronunciation) | Meaning | Synonyms | Antonyms | Example Sentence |
|---|---|---|---|---|
| population (পপিউলেশন) | কোনো স্থানে বসবাসকারী মানুষের সংখ্যা (the number of people living in a place) | people (মানুষ); inhabitants (বাসিন্দারা); residents (অধিবাসীরা) | — | The population of Bangladesh is growing. বাংলাদেশের জনসংখ্যা বৃদ্ধি পাচ্ছে। |
| density (ডেনসিটি) | প্রতি বর্গকিলোমিটার ভূমিতে মানুষের সংখ্যা (the number of people per square kilometre) | concentration (ঘনত্ব); closeness (সন্নিকটতা); crowdedness (ভিড়পূর্ণতা) | sparseness (বিরলতা); emptiness (শূন্যতা) | Population density can be found by dividing total population by total area. মোট জনসংখ্যাকে মোট ক্ষেত্রফল দিয়ে ভাগ করে জনঘনত্ব নির্ণয় করা যায়। |
| resources (রিসোর্সিজ) | প্রকৃতি থেকে পাওয়া বা ব্যবহারের উপযোগী সরবরাহ (useful supplies provided by nature) | supplies (সরবরাহ); materials (উপকরণ); assets (সম্পদ) | waste (অপচয়); shortage (ঘাটতি); lack (অভাব) | We need more food, land and other natural resources. আমাদের আরও খাদ্য, ভূমি ও অন্যান্য প্রাকৃতিক সম্পদ দরকার। |
| shortage (শর্টিজ) | কোনো কিছুর অপর্যাপ্ত অবস্থা (a condition in which there is not enough of something) | lack (অভাব); scarcity (দুর্লভতা); insufficiency (অপর্যাপ্ততা) | abundance (প্রাচুর্য); plenty (প্রচুরতা); excess (অতিরিক্ততা) | Population growth may cause a shortage of food and land. জনসংখ্যা বৃদ্ধি খাদ্য ও ভূমির ঘাটতি ঘটাতে পারে। |
| pollution (পলিউশন) | বায়ু, পানি বা মাটির ক্ষতিকর দূষণ (harmful contamination of air, water, or soil) | contamination (দূষণ); dirt (ময়লা); impurity (অশুদ্ধতা) | cleanliness (পরিচ্ছন্নতা); purity (বিশুদ্ধতা); cleanness (নির্মলতা) | Excessive use of chemical fertiliser can cause soil pollution. অতিরিক্ত রাসায়নিক সার ব্যবহার মাটিদূষণ ঘটাতে পারে। |
| renewable (রিনিউয়েবল) | প্রাকৃতিকভাবে পুনরায় প্রতিস্থাপনযোগ্য (able to be replaced naturally) | replaceable (প্রতিস্থাপনযোগ্য); reusable (পুনর্ব্যবহারযোগ্য); restorable (পুনরুদ্ধারযোগ্য) | non-renewable (অপুনর্নবীকরণযোগ্য); limited (সীমিত); exhaustible (নিঃশেষযোগ্য) | A solar panel uses renewable resources to produce electricity. একটি সৌর প্যানেল বিদ্যুৎ উৎপাদনে নবায়নযোগ্য সম্পদ ব্যবহার করে। |
| extinction (এক্সটিংকশন) | কোনো জীবের সম্পূর্ণ বিলুপ্তি (the complete disappearance of a kind of living thing) | disappearance (অদৃশ্য হয়ে যাওয়া); destruction (ধ্বংস); elimination (বিলুপ্তি) | survival (বেঁচে থাকা); existence (অস্তিত্ব); continuation (ধারাবাহিকতা) | The loss of forests causes the extinction of living things. বনভূমি হারিয়ে গেলে জীবন্ত প্রাণীর বিলুপ্তি ঘটে। |
Worked Example Series
Ex. Find the increase in Bangladesh's population from 2011 to 2022.
Sol:
Increase = 16 crore 51 lac − 14 crore 97 lac
Increase = 1 crore 54 lac
Ans. Increase = 1 crore 54 lac
Increase = 16 crore 51 lac − 14 crore 97 lac
Increase = 1 crore 54 lac
Ans. Increase = 1 crore 54 lac
Ex. Find the increase in Bangladesh's population from 1961 to 1974.
Sol:
Increase = 7 crore 64 lac − 5 crore 52 lac
Increase = 2 crore 12 lac
Ans. Increase = 2 crore 12 lac
Increase = 7 crore 64 lac − 5 crore 52 lac
Increase = 2 crore 12 lac
Ans. Increase = 2 crore 12 lac
Ex. Find the increase in Bangladesh's population from 1981 to 1991.
Sol:
Increase = 12 crore 14 lac − 8 crore 99 lac
Increase = 3 crore 15 lac
Ans. Increase = 3 crore 15 lac
Increase = 12 crore 14 lac − 8 crore 99 lac
Increase = 3 crore 15 lac
Ans. Increase = 3 crore 15 lac
Ex. Find the population density of Bangladesh in 1974. Use a total area of 1,47,570 square kilometres.
Sol:
Density = 7,64,00,0001,47,570
Density ≈ 517.7 people per square kilometre
Density ≈ 518 people per square kilometre
Ans. Approximately 518 people per square kilometre
Density = 7,64,00,0001,47,570
Density ≈ 517.7 people per square kilometre
Density ≈ 518 people per square kilometre
Ans. Approximately 518 people per square kilometre
8. Exercise 3 - Synonyms and Antonyms
Read each word and choose the correct synonym or antonym as directed.
| Word (Pronunciation) | Meaning | Synonyms | Antonyms | Example Sentence |
|---|---|---|---|---|
| population (পপুলেশন) | কোনো স্থানে বসবাসকারী মানুষের সংখ্যা (the number of people living in a place) | people (মানুষ); inhabitants (অধিবাসী); residents (বাসিন্দা) | — | The population of Bangladesh is growing. বাংলাদেশের জনসংখ্যা বৃদ্ধি পাচ্ছে। |
| natural (ন্যাচারাল) | প্রকৃতিতে বিদ্যমান বা প্রকৃতি থেকে পাওয়া (existing in or provided by nature) | native (স্থানীয়); organic (জৈব); environmental (পরিবেশগত) | artificial (কৃত্রিম); man-made (মানুষের তৈরি) | Growing human needs put pressure on natural resources. বর্ধমান মানবিক চাহিদা প্রাকৃতিক সম্পদের ওপর চাপ সৃষ্টি করে। |
| environment (এনভায়রনমেন্ট) | মানুষ, প্রাণী ও উদ্ভিদ যে পরিবেশে বাস করে (the surroundings where living things live) | surroundings (পারিপার্শ্বিক পরিবেশ); ecosystem (বাস্তুতন্ত্র); habitat (আবাসস্থল) | — | Population growth has several impacts on the environment. জনসংখ্যা বৃদ্ধির পরিবেশের ওপর বিভিন্ন প্রভাব রয়েছে। |
| increasing (ইনক্রিসিং) | সংখ্যা বা পরিমাণে বেশি হওয়া (becoming greater in number or amount) | growing (বর্ধমান); rising (বৃদ্ধিশীল); expanding (প্রসারিত) | decreasing (হ্রাসমান); falling (কমতে থাকা); reducing (কমানো) | World human population is increasing. বিশ্বের মানব জনসংখ্যা বৃদ্ধি পাচ্ছে। |
| resources (রিসোর্সিজ) | প্রকৃতি থেকে পাওয়া বা ব্যবহারের উপযোগী সরবরাহ (useful supplies from nature or available for use) | supplies (সরবরাহ); materials (উপকরণ); assets (সম্পদ) | waste (অপচয়); shortage (ঘাটতি); lack (অভাব) | We need more food, land and other natural resources. আমাদের আরও খাদ্য, ভূমি ও অন্যান্য প্রাকৃতিক সম্পদ দরকার। |
| shortage (শর্টিজ) | কোনো কিছুর অপর্যাপ্ত অবস্থা (a condition in which there is not enough of something) | lack (অভাব); scarcity (দুর্লভতা); insufficiency (অপর্যাপ্ততা) | abundance (প্রাচুর্য); plenty (প্রচুরতা); excess (অতিরিক্ততা) | Population growth may cause a shortage of food and land. জনসংখ্যা বৃদ্ধি খাদ্য ও ভূমির ঘাটতি ঘটাতে পারে। |
| pollution (পলিউশন) | বায়ু, পানি বা মাটির ক্ষতিকর দূষণ (harmful contamination of air, water, or soil) | contamination (দূষণ); dirt (ময়লা); impurity (অশুদ্ধতা) | cleanliness (পরিচ্ছন্নতা); purity (বিশুদ্ধতা); cleanness (নির্মলতা) | Excessive use of chemical fertiliser can cause soil pollution. অতিরিক্ত রাসায়নিক সার ব্যবহার মাটিদূষণ ঘটাতে পারে। |
| renewable (রিনিউয়েবল) | প্রাকৃতিকভাবে পুনরায় প্রতিস্থাপনযোগ্য (able to be replaced naturally) | replaceable (প্রতিস্থাপনযোগ্য); reusable (পুনর্ব্যবহারযোগ্য); restorable (পুনরুদ্ধারযোগ্য) | non-renewable (অপুনর্নবীকরণযোগ্য); limited (সীমিত); exhaustible (নিঃশেষযোগ্য) | A solar panel uses renewable resources to produce electricity. একটি সৌর প্যানেল বিদ্যুৎ উৎপাদনে নবায়নযোগ্য সম্পদ ব্যবহার করে। |
| extinction (এক্সটিংকশন) | কোনো জীবের সম্পূর্ণ বিলুপ্তি (the complete disappearance of a kind of living thing) | disappearance (অদৃশ্য হয়ে যাওয়া); destruction (ধ্বংস); elimination (বিলুপ্তি) | survival (বেঁচে থাকা); existence (অস্তিত্ব); continuation (ধারাবাহিকতা) | The loss of forests causes the extinction of living things. বনভূমি হারিয়ে গেলে জীবন্ত প্রাণীর বিলুপ্তি ঘটে। |
| density (ডেনসিটি) | প্রতি বর্গকিলোমিটার ভূমিতে মানুষের সংখ্যা (the number of people per square kilometre) | concentration (ঘনত্ব); closeness (সন্নিকটতা); crowdedness (ভিড়পূর্ণতা) | sparseness (বিরলতা); emptiness (শূন্যতা); openness (উন্মুক্ততা) | Population density can be found by dividing total population by total area. মোট জনসংখ্যাকে মোট ক্ষেত্রফল দিয়ে ভাগ করে জনঘনত্ব নির্ণয় করা যায়। |
Answer Key
- population — people; inhabitants; residents
- natural — artificial; man-made
- environment — surroundings; ecosystem; habitat
- increasing — decreasing; falling; reducing
- resources — supplies; materials; assets
- shortage — abundance; plenty; excess
- pollution — cleanliness; purity; cleanness
- renewable — non-renewable; limited; exhaustible
- extinction — survival; existence; continuation
- density — sparseness; emptiness; openness
Worked Example Series
Ex. Find the increase in Bangladesh's population from 1991 to 2001.
Sol:
Increase = 12 crore 93 lac − 12 crore 14 lac
Increase = 79 lac
Ans. Increase = 79 lac
Ex. Find the increase in Bangladesh's population from 2001 to 2011.
Sol:
Increase = 14 crore 97 lac 72 thousand 364 − 12 crore 93 lac
Increase = 2 crore 4 lac 72 thousand 364
Ans. Increase = 2 crore 4 lac 72 thousand 364
Ex. Find the increase in Bangladesh's population from 2011 to 2022.
Sol:
Increase = 16 crore 51 lac − 14 crore 97 lac 72 thousand 364
Increase = 1 crore 53 lac 27 thousand 636
Ans. Increase = 1 crore 53 lac 27 thousand 636
Ex. Find the population density of Bangladesh in 2011. Use a total area of 1,47,570 square kilometres.
Sol:
Density = 14,97,72,3641,47,570
Density ≈ 1,014.9 people per square kilometre
Density ≈ 1,015 people per square kilometre
Ans. Approximately 1,015 people per square kilometre
9. Exercise 4 - Make Sentences
Instruction: Make a sentence with each word. The model sentences are given in the answer key below.
| Word (Pronunciation) | Meaning | Synonyms | Antonyms | Example Sentence |
|---|---|---|---|---|
| population (pop-yoo-LAY-shun) | The number of people living in a place. | people; inhabitants; residents | — | The population of Bangladesh is growing. The number of people in Bangladesh is increasing. |
| density (DEN-si-tee) | The number of people per square kilometre of land area. | concentration; closeness; crowdedness | sparseness; emptiness; openness | Population density in Bangladesh is very high. Many people live within the land area. |
| resources (ree-SOR-siz) | Useful supplies provided by nature or available for use. | supplies; materials; assets | waste; shortage; lack | We need natural resources for a growing population. People need useful supplies from nature. |
| shortage (SHOR-tij) | A condition in which there is not enough of something. | lack; scarcity; insufficiency | abundance; plenty; excess | Population growth may cause a shortage of food and land. A larger population may create a lack of food and land. |
| pollution (puh-LOO-shun) | The harmful contamination of air, water, or soil. | contamination; dirt; impurity | cleanliness; purity; cleanness | Excessive use of chemical fertiliser can cause soil pollution. Too much chemical fertiliser can make the soil harmful. |
| renewable (ree-NOO-uh-bul) | Able to be replaced or used again naturally. | replaceable; reusable; restorable | non-renewable; limited; exhaustible | A solar panel uses a renewable resource to produce electricity. Solar energy can be used naturally again. |
| extinction (ek-STINGK-shun) | The complete disappearance of a kind of living thing. | disappearance; destruction; elimination | survival; existence; continuation | The loss of forests causes the extinction of living things. When forests disappear, some living things may disappear completely. |
| environment (in-VY-ruh[n]-ment) | The surroundings in which people, animals, and plants live. | surroundings; ecosystem; habitat | — | Population growth has several impacts on the environment. Population growth can change our surroundings. |
Worked Example Series
Ex. Find the increase in Bangladesh's population from 1961 to 1974.
Sol: Increase = 7 crore 64 lac − 5 crore 52 lac
Increase = 2 crore 12 lac
Ans. Increase = 2 crore 12 lac
Increase = 2 crore 12 lac
Ans. Increase = 2 crore 12 lac
Ex. Find the increase in Bangladesh's population from 1974 to 1981.
Sol: Increase = 8 crore 99 lac − 7 crore 64 lac
Increase = 1 crore 35 lac
Ans. Increase = 1 crore 35 lac
Increase = 1 crore 35 lac
Ans. Increase = 1 crore 35 lac
Ex. Find the increase in Bangladesh's population from 1981 to 1991.
Sol: Increase = 12 crore 14 lac − 8 crore 99 lac
Increase = 3 crore 15 lac
Ans. Increase = 3 crore 15 lac
Increase = 3 crore 15 lac
Ans. Increase = 3 crore 15 lac
Ex. Find the growth of the world population from the early 1800s to today.
Sol: Growth = 700 crore − 100 crore
Growth = 600 crore
Ans. Growth = 600 crore
Growth = 600 crore
Ans. Growth = 600 crore
Ex. Find the population density formula for a country.
Sol: Population density = Total populationTotal area
For Bangladesh, total area = 1,47,570 square kilometres
Therefore, density = Population1,47,570 people per square kilometre
Ans. Population density is found by dividing total population by total area.
For Bangladesh, total area = 1,47,570 square kilometres
Therefore, density = Population1,47,570 people per square kilometre
Ans. Population density is found by dividing total population by total area.
10. Vocabulary MCQ (1-10)
Practice Questions
Meanings of Key Words
1. What does population mean?
A. The number of people living in a placeB. The land area of a countryC. The amount of rainfallD. The number of factories
Sol: [A] Population means the number of people living in a place.
2. Which word means the number of people per square kilometre of land?
A. GrowthB. DensityC. ExtinctionD. Shortage
Sol: [B] Population density shows how many people live in a square kilometre.
3. In the chapter, what are natural resources?
A. Useful supplies from natureB. Harmful gases onlyC. Diseases in dense populationsD. Roads and industries
Sol: [A] Resources are useful supplies provided by nature or available for use.
4. A shortage of food means that there is—
A. more than enough foodB. no need for foodC. not enough foodD. fresh food everywhere
Sol: [C] A shortage is a condition in which there is not enough of something.
Environment and Effects
5. Which sentence uses pollution correctly?
A. Pollution makes forests grow faster.B. Chemical fertilisers can cause soil pollution.C. Pollution means clean water.D. Pollution increases available land.
Sol: [B] Excessive chemical fertilisers can cause soil and water pollution.
6. What may happen when forests are cleared?
A. Habitats may be destroyed.B. Population density becomes zero.C. Food needs disappear.D. All resources become renewable.
Sol: [A] Clearing forests can destroy habitats and cause extinction.
7. Which word describes the surroundings in which people, animals, and plants live?
A. EnvironmentB. ShortageC. DensityD. Growth
Sol: [A] The environment is the surroundings where living things live.
Renewable Resources and Technology
8. Which example shows a renewable resource?
A. CoalB. Fossil fuelC. Solar energyD. Chemical pesticide
Sol: [C] Solar panels use a renewable resource to produce electricity.
9. What does renewable mean?
A. Able to be replaced or used again naturallyB. Unable to be used againC. Harmful to every habitatD. Made only in factories
Sol: [A] Renewable resources can be replaced or used again naturally.
Word Usage in Context
10. Which sentence uses extinction in the chapter's meaning?
A. Extinction means a rise in population.B. Forest loss can cause the extinction of living things.C. Extinction supplies more land.D. Extinction reduces the need for shelter.
Sol: [B] Extinction is the complete disappearance of a kind of living thing.
11. Quick Revision List
| Word (Pronunciation) | Meaning | Synonyms | Antonyms | Example Sentence |
|---|---|---|---|---|
| population (pop-yoo-LAY-shun) | The number of people living in a place. | people; inhabitants; residents | — | The population of Bangladesh was 14 crore 97 lac 72 thousand and 364 in 2011. This gives the number of people at a particular time. |
| density (DEN-si-tee) | The number of people per square kilometre of land area. | concentration; closeness; crowdedness | sparseness; emptiness; openness | Population density in Bangladesh is very high. Many people live within the land area. |
| resources (ree-SOR-siz) | Useful supplies provided by nature or available for use. | supplies; materials; assets | waste; shortage; lack | Growing human needs can create pressure on natural resources. More human needs can put pressure on supplies from nature. |
| shortage (SHOR-tij) | A condition in which there is not enough of something. | lack; scarcity; insufficiency | abundance; plenty; excess | Population growth may cause a shortage of food, clothing, housing, and land. A growing population may not have enough of these needs. |
| pollution (puh-LOO-shun) | The harmful contamination of air, water, or soil. | contamination; dirt; impurity | cleanliness; purity; cleanness | Excessive chemical fertiliser and pesticide can cause soil pollution and water pollution. Too many farm chemicals can make soil and water harmful. |
| renewable (ree-NOO-uh-bul) | Able to be replaced or used again naturally. | replaceable; reusable; restorable | non-renewable; limited; exhaustible | A solar panel uses a renewable resource to produce electricity. Solar energy can be used as an alternative to non-renewable resources. |
| extinction (ek-STINGK-shun) | The complete disappearance of a kind of living thing. | disappearance; destruction; loss | survival; existence; continuation | The loss of forests causes the extinction of living things. When forests are lost, some living things may disappear completely. |
Dictionary entries: 7
◆ Key Points
- Population means the number of people living in a place.
- Population density means the number of people per square kilometre of land area.
- Population density is found by dividing the total population by the total area of a country.
- As population grows, the need for food, water, shelter, clothing, and land increases.
- Growing human needs can put pressure on natural resources.
- Population growth may cause shortages of food, clothing, housing, and land.
- Germs can spread faster in denser populations.
- Clearing forests can change ecosystems, destroy habitats, and cause extinction.
- Excessive chemical fertilisers and pesticides can cause soil and water pollution.
- Burning fossil fuel can cause air pollution, global warming, and acid rain.
- Science and technology can help produce more food and reduce the use of non-renewable resources.
- Solar panels use renewable resources, and hybrid cars can reduce the use of fossil fuel.
12. Practice Bank
Further Vocabulary
| Word (Pronunciation) | Meaning | Synonyms | Antonyms | Example Sentence |
|---|---|---|---|---|
| cultivate (KUL-ti-vayt) | To grow crops on land (to grow plants). | grow; farm; plant | neglect; abandon | People clear forests to cultivate more crops. People remove forests to grow more crops. |
| livestock (LIV-stok) | Farm animals kept by people (animals kept on a farm). | farm animals; cattle; animals | — | People clear forests to farm more livestock. People remove forests to keep more farm animals. |
| shelter (SHEL-ter) | A place that protects people from the surroundings (a place to live safely). | housing; home; protection | exposure; openness | People use more land for shelters, roads, and industries. People use more land for homes, roads, and industries. |
| ecosystem (EE-koh-sis-təm) | A system of living things and their surroundings (a natural community). | environment; habitat; natural system | — | The loss of forests causes changes in the ecosystem. When forests disappear, the natural system changes. |
| habitat (HAB-i-tat) | The natural home of a living thing (the place where it lives). | home; environment; dwelling | — | The loss of forests destroys the habitats of living things. When forests are lost, living things lose their natural homes. |
| deforestation (dee-for-i-STAY-shən) | The clearing or loss of forests (the removal of forests). | forest clearing; tree removal; clearing | afforestation; reforestation | Deforestation can cause soil erosion and landslides. Forest clearing can damage soil and cause landslides. |
| erosion (i-ROH-zhən) | The wearing away of soil (the loss of soil). | wearing away; washing away; loss | — | Deforestation can cause soil erosion. Clearing forests can cause the loss of soil. |
| landslides (LAND-slydz) | The movement of soil and rock down a slope (earth moving downhill). | earth movement; slope failure; rockfall | — | Deforestation can cause soil erosion and landslides. Clearing forests may make soil and rocks move downhill. |
| fertiliser (FUR-tə-ly-zər) | A substance used to help plants grow (plant food added to soil). | plant food; manure; nutrient | — | Chemical fertiliser is used in agriculture to grow plants well. Farmers use plant food to help crops grow. |
| pesticide (PEST-i-syd) | A chemical used to control harmful pests (a pest-killing substance). | pest killer; chemical; insecticide | — | Excessive use of pesticide can cause soil pollution and water pollution. Too much pest-killing chemical can harm soil and water. |
| biotechnology (BY-oh-tek-NOL-ə-jee) | The use of living things or biological processes in technology (technology used to improve plants). | biological technology; plant technology | — | Biotechnology is used to grow plants that are more nutritious and disease resistant. Biological technology helps produce better plants. |
Dictionary entries: 12
Creative Question Bank
1. A town had a population of 8 crore 99 lac people in 1981. By 2011, its population had grown to 14 crore 97 lac 72 thousand and 364. The town also needed more food, water, shelter, clothing, and land.
(a) What is population density? [2]
(b) Explain two ways in which population growth increases human needs. [4]
(c) Describe two problems that may occur when population grows. [4]
(a) What is population density? [2]
(b) Explain two ways in which population growth increases human needs. [4]
(c) Describe two problems that may occur when population grows. [4]
2. People in an area cleared forests to cultivate crops and farm more livestock. They also used the land for shelters, roads, and industries. The forest became smaller and many living things lost their homes.
(a) What is a habitat? [2]
(b) Explain two effects of clearing forests on the environment. [4]
(c) Show how the loss of forests can lead to the extinction of living things. [4]
(a) What is a habitat? [2]
(b) Explain two effects of clearing forests on the environment. [4]
(c) Show how the loss of forests can lead to the extinction of living things. [4]
3. Farmers used chemical fertilisers and pesticides to produce more food. After repeated use, the soil became polluted and harmful substances entered nearby water.
(a) What is a pesticide? [2]
(b) Why do farmers use chemical fertilisers and pesticides? [4]
(c) Explain how excessive use of these chemicals can affect soil and water. [4]
(a) What is a pesticide? [2]
(b) Why do farmers use chemical fertilisers and pesticides? [4]
(c) Explain how excessive use of these chemicals can affect soil and water. [4]
4. A power plant and several vehicles burnt fossil fuel. The gases released from them polluted the air and contributed to global warming and acid rain. A hybrid car was later introduced in the area.
(a) What is fossil fuel used for? [2]
(b) Write two harmful results of burning fossil fuel. [4]
(c) Explain how a hybrid car can reduce the use of fossil fuel. [4]
(a) What is fossil fuel used for? [2]
(b) Write two harmful results of burning fossil fuel. [4]
(c) Explain how a hybrid car can reduce the use of fossil fuel. [4]
5. Scientists developed agricultural machinery and used biotechnology to produce more nutritious, disease-resistant, and productive plants. Solar panels were also used to produce electricity from a renewable resource.
(a) What is biotechnology? [2]
(b) Describe two contributions of science and technology to food production. [4]
(c) Explain how solar panels and other technologies can help solve population problems. [4]
(a) What is biotechnology? [2]
(b) Describe two contributions of science and technology to food production. [4]
(c) Explain how solar panels and other technologies can help solve population problems. [4]
Hints: Use the chapter terms population density, natural resources, human needs, pollution, extinction, renewable resources, agricultural machinery, biotechnology, and hybrid car in your answers.