ICSE Living Science Biology for Class 6 Solutions Chapter 1 Life on Earth
Check Your Progress
Fill in the blanks.
Question 1.
A ………… is the basic unit of life.
Answer:
A cell is the basic unit of life.
Question 2.
Living beings that have many cells are called …………. organisms.
Answer:
Living beings that have many cells are called multicellular organisms.
Question 3.
Green plants make food from water and carbon dioxide in the presence of …………
Answer:
Green plants make food from water and carbon dioxide in the presence of sunlight.
Question 4.
………….. respiration involves breaking down of food in each cell using the oxygen taken in.
Answer:
Internal or cellular respiration involves breaking down of food in each cell using the oxygen taken in.
Question 5.
The movement of animals from one place to another is called …………..
Answer:
The movement of animals from one place to another is called locomotion.
Question 6.
Flowers of the ………… plant change their position to face the sun.
Answer:
Flowers of the sunflower plant change their position to face the sun.
Check Your Progress
Fill in the blanks.
Question 1.
The reaction which an organism produces towards a stimulus is called …………..
Answer:
The reaction which an organism produces towards a stimulus is called response.
Question 2.
The stem of a plant grows towards the source of ………….
Answer:
The stem of a plant grows towards the source of light.
Question 3.
The ………….. of an organism is the time between its birth and death.
Answer:
The life span of an organism is the time between its birth and death.
Question 4.
The average life span of a cat is ………….. years.
Answer:
The average life span of a cat is 12-14 years.
Question 5.
…………. is the condition when living beings are no longer alive.
Answer:
Death is the condition when living beings are no longer alive.
A. Tick the most appropriate answer.
Question 1.
A unicellular organism is made up of –
a. only one cell.
b. no cell.
c. many cells.
d. two cells
Answer:
a. only one cell.
Question 2.
Green plants are –
a. non-living
b. autotrophs.
c. heterotrophs.
d. dead
Answer:
b. autotrophs.
Question 3.
Human beings give out carbon dioxide through –
a. lungs.
b. ears.
c. kidneys.
d. heart.
Answer:
a. lungs.
Question 4.
The average life span of human beings is –
a. 70-80 years.
b. 20-30 years.
c. 100-150 years.
d. 24-40 years
Answer:
a. 70-80 years.
Question 5.
Reproduction is the characteristic feature of –
a. plants only.
b. animals only.
Answer:
Living beings reproduce to produce more of their own kind to continue their race.
Praticle Question 1.
Name three unicellular animals.
Answer:
Three unicellular animals are:
(a) Amoeba
(b) Paramecium and
(c) Chlamydomonas.
Praticle Question 2.
How does growth in unicellular organisms differ from growth in multicellular organisms ?
Answer:
Unicellular organisms like Amoeba grow with an increase in the size of the single cell whereas growth in multicellular organisms results from an increase in the number of cells.
Praticle Question 3.
How is the movement of a non-living thing different from that of a living being ?
Answer:
A living being shows movement using energy from within whereas non-living things cannot move on their own. They need external force to provide the energy to move.
D. Answer in detail.
Question 1.
What are autotrophs ? How do they differ from heterotrophs ?
Answer:
Autotrophs are those living beings who manufacture their own food e.g. green plants make their own food using carbon dioxide and water in the presence of sunlight and chlorophyll. Heterotrophs are those organisms which cannot make their own fpod and depend on plants and other anint&ls for their food; e.g’.’-animals and non-green plants.
Question 2.
What is respiration ? What are the various stages it involves? p/
Answer:
The process of toting in oxygen and using it to break down food to release energy, carbon-dioxide and water vapour is called as respiration. It involves two stages.
- Breathing or external respiration – It involves taking in oxygen and giving out carbon-dioxide.
- Internal or cellular respiration – It involves breaking down of food in each cell using the oxygen taken in.
Question 3.
Explain how plants and animals excrete waste products.
Answer:
In many animals, including human beings, excess water along with urea is removed in the form of urine. Carbon dioxide produced during respiration is also a waste product and given out through the lungs. The body gets rid of excess water and salts in the form of sweat through the skin.
Plants throw out waste products, mainly in the form of harmless substances like gums, resins, tannins and latex. They release oxygen, carbon dioxide and water vapour through stomata in the leaves. Solid waste which is stored in leaves and barks of trees is thrown out when plants shed their leaves and bark.
Question 4.
Why do animals move from one place to another?
Answer:
Living organisms move from one place to another for many
reasons like :
(a) in search of food.
(b) to find a shelter.
(c) to protect themselves from their enemies.
Question 5.
Differentiate between plants and animals.
Answer:
Plants :
- Nutrition – Green plants preparetfyeir own food by photosynthesis.(Autotrophic in nature)
- They show locomotion fixed to the soil and do not show free movement Their parts show move-ment .
- Growth – Most of them grow throughout their life.
- Response to stimuli – They show slow response to external stimuli as they have no sense organs.
Animals :
- They cannot make their own food. They obtain their food from plants and other animals. (Heterotrophic in nature).
- Movement – They are from one place to another.
- They stop growing when they reach their adult size.
- They show quick responses to external stimuli as they have sense organs.
Praticle Question 1.
What is the difference between respiration and breathing ?
Answer:
Respiration :
- It is a process of oxidation of food using the oxygen taken in while breathing, to release energy, water and carbon-dioxide.
- It takes place inside the cells of an organism.
- It is also called internal or cellular respiration.
Breathing :
- It is a process of taking in oxygen (inhaling) and giving out carbon-dioxide (exhaling) in living beings.
- It takes place through nose and lungs.
- It is also called external respiration.
Praticle Question 2.
What isim anaerobic respiration?
Answer:
Some organisms do not require oxygen for breaking down of their food. They are said to perform anaerobic (without air) respiration, e.g yeasts.
Praticle Question 3.
You are travelling in a car with all the windows closed in winter. After a while you notice a mist forming on the windows. This mist is made up of tiny droplets of water. Where did they come from ?
Answer:
The mist on the car windows is nothing but the condensed water vapours which we exhale out during breathing. Since the water vapours we exhale are warm but the glass windows are cold in winters, so when the water vapours come in contact with cold glass, they get converted into tiny droplets of water due to condensation.
E. Match the following.
| 1. reproduction | a. any change in environ-ment |
| 2. excretion | b. producing more of one’s own kind |
| 3. stimulus | c. removing waste from the body |
| 4. locomotion | d. taking in oxygen and giving out carbon dioxide |
| 5. external respiration | e. movement from one place to another |
Answer:
| 1. reproduction | b. producing more of their own kind |
| 2. excretion | c. removing waste from the body |
| 3. stimulus | a. any change in environment |
| 4. locomotion | e. movement from one place to another |
| 5. external respiration | d. taking in oxygen and giving out carbon dioxide |
F. Give reasons for the following.
Question 1.
A car engine uses petrol and oxygen to run. It gives off carbon dioxide and: smoke as waste from its exhaust pipe? Can you cad the car a living thing ? Why ?
Answer:
No, we cannot call the car a living thing because it does not grow, it does not respond to stimuli and it does not reproduce.
Question 2.
A few gram seeds are soaked in water for a few hours. These seeds absorb water and become bigger in size. Can you say that seeds are showing growth ? Why ?
Answer:
Yes, the seeds are showing growth as the increase in size is due to multiplication of cells inside the seed.
G. Sort out the given terms into the groups ONLY ANIMALS, ONLY PLANTS and BOTH ANIMALS AND PLANTS.
excretion, respiration, photosynthesis, eating other living things, movement from place to place, growth towards light, growth throughout life, growth stops when adult size is reached Only Animals Only Plants Both Animals and Plant
_____, _____, _____
Answer:
ONLY ANIMALS
→ Movement from place to place – Eating other living things
→ growth stops when adult size is reached
ONLYPLANTS
→ Photosynthesis
→ growth throughout life
→ growth towards light
BOTH ANIMALS AND PLANTS
→ Excretion
→ Respiration
Living Science Biology Class 6 ICSE Solutions