Life Processes | Chapter 5 | Grade-7 | Science and Technology Notes - New Course 2079-2081

Grade-Class 7 Science and Technology Notes of Chapter-5 "Life Processes". Under Chapter-5 'Life Processes' of Class 7 Science subject, Students and teachers will be able to find the notes and solutions of fill in the blanks with suitable words, multiple choice questions (MCQs), match the followings, state whether the following statements are True or False, short answer questions, long answer questions, answer in a single word/single sentence, differentiate between, give reasons (explain), diagrammatic questions, glossary, extra word meanings in Nepali language and extra question answers. The below science notes of Chapter-5 "Life Processes" of class-grade 7 is based on new curriculum of the year 2077/2078-2021 published by Government of Nepal, Ministry of Education, Science and Technology, Curriculum Development Centre. Credit to "Vidyarthi Pustak Bhandar".

Test Your Concept!

1. Fill in the blanks.

a. Breathing is a combined form of inhalation and exhalation.

b. Oxygen is absorbed by diffusion from alveoli of the lungs.

c. Plants take carbon dioxide gas for respiration.

d. Plants have stomata and lenticels for respiration.

e. Plants have xylem and phloem for transportation.

Also Check:

Energy In Daily Life | Chapter 7 | Grade-7 | Science and Technology Notes - New Course 2079-2081

Information and Communication | Chapter 2 | Grade-7 | Science and Technology Notes - New Course 2079-2081

Scientific Studies | Chapter 1 | Grade-7 | Science and Technology Notes - New Course 2079-2081

2.  Multiple choice questions (MCQs):

a. Through which organ does transpiration occur efficiently?

A) leaves

B) roots

C) flowers

D) stem

Answer: A) leaves

b. Which of the following governs the opening and closing of the stomata?

A) xylem

B) guard-cells

C) ground cells

D) phloem

Answer: B) guard-cells

c. Which statement is correct about transpiration?

A) Water is gained by animals.

B) Water is lost by animals.

C) Water is lost by plants.

D) Water is gained by plants.

Answer: C) Water is lost by plants.

d. Which of the following carries food from leaves to other parts of plants?

A) phloem

B) xylem

C) lenticel

D) stomata

Answer: A) phloem

e. Which of the following gas is used by plants in respiration?

A) oxygen

B) water

C) carbon dioxide

D) nitrogen

Answer: C) carbon dioxide

3. Short answer type questions:

a. Which is the site of gaseous exchange in the lungs?

Answer: Alveoli is the site of gaseous exchange in the lungs.

b. Which structure separates the thorax from the abdomen?

Answer: Diaphragm separates the thorax from the abdomen.

#The structure that separates the thorax from the abdomen is Diaphragm.

c. List the various types of respiratory organs in animals.

Answer: The list of the various types of respiratory organs in animals are -

• lungs,
• gills,
• trachea,
• mouth,
• skin, etc.

d. How does an Amoeba respire?

Answer: An amoeba respires through their general body surface (cell membrane).

e. Write the function of the xylem.

Answer: The function of the xylem is - Xylem transports water and minerals from the soil to the leaves for the preparation of food in plants.

f. List the organs which are concerned with excretion.

Answer: The list of organs which are concerned with excretion are -

• leaves,
• stem,
• body surface,
• mouth,
• skin,
• kidneys,
• lungs,
• skin,
• liver,
• large intestine, etc.

g. Name the specialized cells which surround the stomata.

Answer: The name of the specialized cells which surround the stomata is guard cell.

h. What are the functions of stomata?

Answer: The functions of stomata are - (choose as per your need😊)

• The main function of stomata is the exchange of gases by opening and closing the pores in the leaves.
• Stomata helps in removing water from the leaves.
• Stomata takes carbon dioxide and gives out oxygen during the process of photosynthesis.
• Stomata helps in regulating water movement through transpiration.

i. Define absorption.

Answer: The process in which the digested food passes through the intestinal wall into the bloodstream is called absorption.

Or,

Absorption is the process of absorbing nutrients and other materials to the cells after digestion and to transport unnecessary substances.

j. What is transpiration?

Answer: The loss of water in the form of water vapour from the aerial parts of living plants is called transpiration.

Or,

Transpiration is a type of excretion in plants where the excess water is removed in the form of water vapour.

4. Long answer type questions:

a. What is breathing? Describe briefly.

Answer: The process of taking air in for oxygen and giving out carbon dioxide into air with the help of respiratory organs is known as breathing.

Breathing or respiration takes place in both living plants and animals. All living beings get food by different methods. Burning of the food taken by them in the body to release energy is also known as breathing (respiration). Respiration takes place in two steps - aerobic respiration (in the presence of oxygen) and anaerobic respiration (in the absence of oxygen). The organs used to breathe by living beings are leaves, lenticels, gills, lungs, skin, trachea, mouth, body surface, etc. 

#Breathing is a simple process of inhaling oxygen and exhaling carbon dioxide.

b. Define:

i) cutaneous respiration

Answer: The process of breathing through the moist skin by organisms is called cutaneous respiration.

Earthworm, roundworms, etc. have cutaneous respiration. Also frog has the cutaneous respiration while they are inside water. 

ii) pulmonary respiration

Answer: Respiration through lungs is called pulmonary respiration.

#Pulmonary respiration is the process of air flowing into the lungs during inhalation and out of the lungs during exhalation.

iii) internal transportation

Answer: The process of carrying the materials like oxygen, water food to the cells and unnecessary metabolic products to the excretory organs is called internal transportation.

Or,

The process of transferring food, water, minerals, waste, etc. by the help of xylem and phloem in plants and food, nutrients, oxygen, waste, etc. by the help of blood, blood vessels and heart in higher animals is called internal transportation.

iv) conducting tissues

Answer: A group of cells that are responsible for transporting food materials and water to different parts of plants is called conducting tissue. Xylem and phloem are the two conducting tissues in plants.

v) role of diffusion in body

Answer: The process in in which the substances flow from the part with more concentration to the part having less concentration is known as diffusion in body. The role of diffusion in the body is that it control the flow of the substances.

vi) excretory organs of lower animals.

Answer: Lower animals have variation in a large range in their excretion process. Lower animals excrete through body surface by diffusion, mouth, skin, nephridia, malpighian tubules, etc.

c. What is the role of a leaf in excretion? Give your own view.

Answer: Leaves play important role in excretion in plants. Most of the carbon dioxide exits through stomata in leaves. Many excretory products accumulate in leaves. Plants shed leaves to get rid excretory products.

Or,

Leaf of plants helps in excretion in many ways. Excess of water in plants is discarded by transpiration. Leaf helps inhalation and exhalation of carbon dioxide and oxygen in plants respectively and excreted through stomata presents on leaf. Besides these, leaf helps in excretion through a process called abscission. Abscission is falling off old and yellow leaves. By the help of this process plants get rid off toxins, etc.

Or,

The role of a leaf in excretion in plants are as followings :-

• Excess of water in plants is removed by transpiration.
• Carbon Dioxide and Oxygen that can be considered as waste product of respiration and photosynthesis respectively are excreted out with help of stomata present on leaves.
• Leaf also helps in excretion by process called Abscission.

#how does a leaf help in excretion in plants?

d. Describe the functions of the kidneys in short.

Answer: The functions of the kidneys in short are -

• Kidneys/It remove waste products from the body.
• Kidneys/It remove drugs from the body.
• Kidneys/It balance the body's fluids.
• Kidneys/It release hormones that regulate blood pressure.
• Kidneys/It produce an active form of vitamin D that promotes strong, healthy bones.
• Kidneys/It control the production of red blood cells (RBC).

Or,

The functions of the kidneys in short are as follows:

• Removal of waste product - To purify the blood kidneys help to remove waste materials from our body.
• Control of blood pressure - Kidneys produce different hormones (renin, angiotensin, aldosterone, prostaglandin, etc.) that help to regulate water and salt in the body, which plays vital roles in the maintenance of good blood pressure control.
• Removal of excess fluid - Kidneys regulate the fluid balance by excreting excess amount of water as urine while retaining the necessary amount of water in the body, that is essential for living.
• Red blood cell (RBC) production - In kidneys, a hormone called Erythropoietin is present which plays important role in producing Red Blood Cell (RBC). If there is a failure of kidneys, production of RBC is decreased and causes low hemoglobin (anemia).
• To maintain healthy bones - Kidneys convert vitamin D into it's active form which is essential for the absorption of calcium from food, growth of the bones and teeth, and keep the bones strong and healthy.

#what are the functions of kidneys?

e. List the various excretory organs of animals and their role in excretion.

Answer: The list of various excretory organs of animals and their role in excretion are given below:-

• Body Surface - Mostly unicellular and some multicellular animals excrete unnecessary things through the body surface by the process of diffusion, like, protozoans, poriferans, coelenterates, etc.
• Mouth - Coelenterates use mouth and body surface to excrete waste substances.
• Skin - The skin excretes urea, salt and excess water in the form of sweat.
• Kidneys - The kidneys remove waste substance, balance the body's fluid, remove drugs, regulate blood pressure, controls RBC, etc.
• Lungs - The lungs help to throw out carbon dioxide and water vapour of the animals body.
• Liver - The liver changes more harmful ammonia into less harmful urea.
• Large intestine - Large intestine expels the undigested solid waste in the form of faecal matters.

f. Explain in your own words how excretion takes place in plants.

Answer: Removal of of the waste and toxic products from the body is called an excretion. Below are the ways of excretion takes place in plants -

• Plants excretes through the process of Transpiration.
• Plants excretes through the minutes pores called stomata present in the leaves.
• Plants excretes through lenticels (barks of stem and skin of fruits and vegetables).

Or,

Plants produce two gaseous waste products i.e. oxygen during photosynthesis and carbon dioxide during respiration. Excretion of gaseous waste in plants takes place through stomatal pores on leaves. Excess of water is also excreted from the plant body through the stomatal pores and from the surfaces of fruits and stems.

g. How does respiration take place in insects?

Answer: The respiration takes place in insects by following ways -

Insects have a network of air tubes called tracheae (malpighian tubules) for gas exchange. Oxygen rich air rushes through spiracles into the tracheal tubes, diffuses into the body tissue, and reaches every cell of the body. Similarly, carbon dioxide from the cells goes into the tracheal tubes and moves out through spiracles.

Or,

The respiration takes place in insects through the malpighian tubules (tracheal tubes) connected to the digestive tract.

h. Describe the internal transportation in human beings in short.

Answer: The internal transportation in human beings are carried out by the components of the transport system in humans - heart, blood and blood vessels. 

The heart pump oxygenated blood throughout the body and receives deoxygenated blood from the various body parts and sends this impure blood to the lungs for oxygenation. Blood transports the following substances - Gases, oxygen and carbon dioxide, between the lungs and rest of the body and nutrients from the digestive tract and storage sites to the rest of the body. The blood vessels transport blood throughout the body.

#What are the components of the transport system in human beings? What are the functions of these components?

5. Differentiate between:

a. respiration in insects and fish.

Answer: The difference between respiration in insects and fish are -

Respiration in Insects.	Respiration in Fish.
1. Insects breathe through small branched tubes called tracheal tubes.	1. Fish breathes through the gills.
2. The respiration in insects is known as tracheal respiration.	2. The respiration in fish is known as gills respiration.
3. Insects use tracheal system to take oxygen from environment through openings called spiracles.	3. Fish use gills to take oxygen dissolved in water and diffuse carbon dioxide out of the bloodstream.

b. aerobic and anaerobic respiration.

Answer: The difference between aerobic and anaerobic respiration are -

Aerobic Respiration	Anaerobic Respiration
1. Oxygen is present.	1. Oxygen is absent.
2. Gases are exchanged.	2. Gases are not exchanged.
3. Aerobic Respiration takes place in the cytoplasm and the mitochondria.	3. Anaerobic Respiration takes place only in the cytoplasm.
4. Glucose breaks down into carbon dioxide and water.	4. Glucose breaks down into ethyl alcohol, carbon dioxide, and energy.
5. Aerobic Respiration is found in all higher organisms like mammals.	5. Anaerobic Respiration is found in all lower organisms such as bacteria and yeast.
6. Aerobic Respiration releases more energy.	6. Anaerobic Respiration releases less energy than aerobic respiration.

c. excretion in plants and animals.

Answer: The difference between excretion in plants and animals are -

Excretion in Plants.	Excretion in Animals.
1. The process of removal of unwanted gas (oxygen, carbon dioxide), waste products (water, resins, gums, latex), etc. from plants is known as excretion in plants.	1. The process of removal of unwanted gas (oxygen, carbon dioxide), waste products (sweats, urea, uric acid, bile pigments, excess salts), etc. from animals is known as excretion in plants.
2. Excretion in plants involves transpiration, storing, diffusion.	2. Excretion in animals involves precipitation, discharge of urine, cellular respiration.
3. Plant doesn't have any particular organ for excretion.	3. Animals have skin, lungs and kidney for excretion.

d. inhalation and exhalation.

Answer: The difference between inhalation and exhalation are -

Inhalation	Exhalation
1. The process of taking in air containing oxygen into the lungs through the nose is called inhalation.	1. The process of taking out air containing carbon dioxide from the body through the nose is called exhalation.
2. Chest cavity size increases.	2. Chest cavity size decreases.
3. Volume of lungs become inflated.	3. Volume of lungs deflated.
4. The air pressure reduces inside the lungs.	4. The air pressure increases inside the lungs.
5. The behaviour of the ribcage moves forward and outward.	5. The behaviour of the ribcage moves downward and inward.
6. Oxygen is taken into the blood.	6. Carbondioxide is taken off from the blood.

6. Give reasons:

a. Cells need energy.

Answer: Cells are the smallest structural and functional units of an organism. Each cell of an organism performs certain functions such as nutrition, transport, excretion and reproduction. To perform these functions, the cell needs energy.

Or,

Cells need energy because they have to do work. Work need energy. They'll die without ATP (Adenosine Tri Phosphate). Cells do life processes in organism which needs energy.

Or,

No living cell in an organism remains without any function. To carry out any metabolic activity in living organism, energy is essential. So, all living cells require energy for survival and proper functioning.

Or,

Cells need energy because to generate and maintain the biological order that keeps them alive.

b. Respiration is called cellular respiration.

Answer: Respiration is called the cellular respiration because it takes place within the cells using enzymes as the catalyst.

Or,

Respiration is called the cellular respiration because it takes place inside the cells where oxygen reacts with foods to release energy.

To release energy in cell, oxygen reacts with food inside the cells and the respiration takes inside the cell.

c. Frequent urination is done in winter.

Answer: Frequent urination is done in winter because sweating does not occur, urine is diluted and clear and the urination is regular.

Or,

We sweats less in winter. It means more fluid for our kidneys to process which makes us frequent urination in winter.

Or,

Frequent urination is done in winter because when we’re cold, our body prepares to stave off hypothermia by constricting our blood vessels to prevent blood flow to our skin and extremities. This causes an increase in blood pressure, which our body then tries to regulate by forcing our kidneys to filter out excess fluid.

d. We should drink more water in summer.

Answer: We should drink more water in summer because a large amount of water passes out in the form of sweat which makes urine concentrated/dense and cause dehydration.

Or,

We get dehydrated due to more humidity, temperature especially during in summer. So, to keep ourselves active, energetic and hydrated we should drink more water in summer.

e. Leaves have stomata.

Answer: Leaves have stomata to exchange gases (carbon dioxide and oxygen), for photosynthesis and for transpiration.

Or,

Leaves have stomata because they can respire like humans. Humans have nose to respire and same leaves have stomata. Leaves absorb carbon dioxide and give out oxygen through stomata which is taken by humans and animals.

Or,

Leaves have stomata to prepare food via photosynthesis, transpiration and for respiration.

Or,

Leaves have stomata because of the following reasons:-

• To receive carbon dioxide.
• To release oxygen.
• For photosynthesis.
• For Transpiration.

#why do leaves have stomata?

f. Fruit and stem have lenticels.

Answer: Lenticels permit the exchange of gases between the environment and the internal tissue spaces of the organs (stems and some fruits). So, Fruit and stem have lenticels.

Or,

Fruit and stem have lenticels because lenticels permit the entrance of oxygen and simultaneously the output of carbon dioxide and water vapour.

g. Fish can survive inside water.

Answer: Fish can survive inside water because it has gills to breathe which allows it to filter dissolved oxygen from water and also has swim bladder, skin with scales, fins, streamlined body structure, etc.

Or,

Fish can survive inside water because of the following reasons:-

• Fish has gills to respire.
• Fish has swim bladder to swim.
• Fish has fins to move swiftly.
• Fish has fin tails to change the direction.
• Fish has skin with scales to let water run over the body easily when swimming.

Or,

Fish can survive (adapt) inside water because it can only absorb oxygen dissolved in water for respiration, not from air. So, fish must have water to survive.

h. Frog have soft and moist skin.

Answer: Frog have soft and moist skin because it respire through the skin when they are underwater.

Or,

Frog have soft and moist skin because it (soft and moist skin) easily absorb the dissolved oxygen from water and helps in respiration.

Or,

Frog have soft thin and moist skin because it respire through the skin inside water for gaseous exchange.

7. Diagrammatic questions:

a. Draw a human urinary system and label it.

Answer:

Fig: Human Urinary System

b. Sketch a neat and labelled diagram of the respiratory system.

Answer:

Fig: Human Respiratory System

c. Study the diagram and answer the following questions:

i) What is it?

Answer: It is a stomata.

ii) At which part of a plant is it found?

Answer: It (Stomata) is found in leaves of a plant.

iii) How does it help plants?

Answer: It (stomata) helps plant in photosynthesis process, for respiration and transpiration.

iv) Name the bean-shaped cells.

Answer: The bean-shaped cells are guard cells.

v) What is the function of the bean-shaped cells?

Answer: The function of the bean-shaped cells (guard cells) is to open and close stomata.

d. When two plants were kept for five hours, water droplets were seen at the inner surface of the bell jar P1.

i) Which cells play a role in the evaporation of water?

Answer: Guard cells play a role in the evaporation of water.

ii) Name the process shown in the diagram.

Answer: Transpiration process.

iii) Does this process occur in animals?

Answer: No. This process doesn't occur in animals.

8. Extra Questions Answers:

a. What are the organs of the human circulatory system?

Answer: The organs of the human circulatory system are heart, arteries, veins and capillaries.

#From above grade/class-7 science notes of Chapter-5 "Life Processes" New Course 2079-2081, we hope students will be able to:

• Describe the transportation and absorption processes in plants and animals.
• Describe and compare the excretion in plants and animals.
• Introduce respiration in plants and animals and describe it's importance.

#Thanks for visiting us. We are really happy providing the notes of Grade/Class-7 Science, 'Life Processes' Notes based on new course of year 2079-2081 under Science and Technology. Please leave comments or suggestions so that we can improve.😊

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