(1) Suggest the appropriate word for the blanks.
(a) Every living organism produces another living organism like itself is called Reproduction.
(b) Growth and Reproduction are the main characteristics of living organisms.
(c) The growth and development of living organisms due to food is called the Nutrition of living organisms.
(d) The body of living organism is made up of Cells.
(2) Birds, fish and animals can move and change their position on their own. Shed leaves, as well as vehicles like tractors and bullock carts can also change their position. What are the important differences between these two types of movements?
Answer:
Birds, fish and animals move on their own. Their movement is a characteristic of living organisms and occurs in response to stimuli. Shed leaves, tractors and bullock carts cannot move on their own. They change position only because of external forces such as wind, humans or animals.
(3) Germs of many diseases are extremely microscopic. They are so small that they cannot be seen with the naked eye. Do such living organisms reproduce? What do you think? Explain how you decided this.
Answer:
Yes, such microscopic living organisms reproduce. Reproduction is a characteristic of all living organisms. Since disease-causing germs are living organisms, they also reproduce and increase in number.
(4) Explain that animals like rats, cats and dogs show awareness of their surroundings through their behaviour? Write down your experiences about it and observations of how they behave in different situations.
Answer:
- A dog runs towards food when it smells it.
- A cat quickly runs away when it senses danger.
- Rats hide when they hear a sudden sound.
- Dogs bark at strangers.
These behaviours show that they sense their surroundings and respond to stimuli.
(5) Make a list of different types of animal movements along with the animals that move in those ways.
Answer.
- Walking – Dog, Cat, Cow
- Running – Horse, Deer
- Jumping – Frog, Rabbit
- Flying – Sparrow, Pigeon, Butterfly
- Swimming – Fish, Turtle
- Crawling – Snake, Earthworm
(6) Plants respond to stimuli. Write down as many observations and experiences as you can which demonstrate this.
Answer:
- Roots grow towards moisture in the soil.
- Branches and stems grow towards sunlight.
- Leaves of some plants fold at night and open in the morning.
- Flower buds bloom when they open their petals.
- Plants respond to changes in weather and temperature.
(7) Turtles stay in water for a long time. Why do they come to the surface repeatedly and poke their heads out of the water? Fish, however, do not try this. Why?
Answer:
Turtles come to the surface to breathe air through their lungs. Fish do not need to come to the surface because they breathe oxygen dissolved in water through their gills.
(8) The life cycle of a frog is given below in a jumbled order. Give the correct number in the boxes to put them in the proper sequence.
Answer:
From left to right in the picture:
- Tadpoles = 2
- Adult Frog = 5
- Eggs = 1
- Tadpole with hind legs = 3
- Young Frog = 4
Answer (left to right): 2, 5, 1, 3, 4
(9) Classify the following into living and non-living groups based on their characteristics.
Answer:
Living:
- Butterfly
- Fish
- Tree
Non-living:
- Stone
- Bicycle
- Book
- Air
- Kite
- Bus
(10) Write answers to the following questions.
(A) What are the effects on the animals when there is a drought and there is no food or water available for them?
Answer:
Animals do not get enough food and water. They become weak, may migrate to other places in search of food and water, and some may die.
(B) A tiger cub grows; does it also develop? Explain this statement.
Answer:
Yes. As a tiger cub grows, it not only increases in size and weight but also develops new abilities and skills. This progress in the body and abilities is called development.
Project
Talk to the elders and collect information from them about where and how natural gum is obtained and what other substances are obtained in the similar way.
Answer:
Natural gum is obtained from the stems and trunks of certain trees such as Acacia (Babool) trees. Small cuts are made in the bark of the tree. A sticky liquid oozes out and hardens on exposure to air. This hardened substance is collected as natural gum.
Other substances obtained in a similar way are:
- Rubber – obtained from rubber trees.
- Resin – obtained from pine trees.
- Latex – obtained from certain plants and trees.