Science Flashcards
What is the need for separation?
To separate harmful or non-useful substances.
To separate useful components, if we need to use them separately.
Two separate particles of different sizes and materials.
Example, Tea leaves are separated from tea with a strainer.
Example, stone pieces from wheat, rice, and pulses are handpicked. 
Principles of separation
- The substance present in a mixture retain their original property like particle size, density, et cetera.
- We use the differences in any anyone of these properties in the components of a mixture to separate them.
What are the different methods of separation?
Solid-solid
Handpicking is the process of removing the impurities or non-substances by using hands.
We can use handpicking process to separate slightly larger sized impurities, like pieces of dust, stones, and husk from wheat, rice, and pulses.
Winnowing is the process used to separate heavier and lighter components of a mixture by wind or by blowing air. 
State the characteristics of living organisms
Living organism need food
Living organism show
Living organism respire
Living organism respond to stimily
Living organism excrete
Living organism reproduce their own kind
Living organisms show movement
Living organisms die
Living organisms may have all the characteristics mentioned above, while nonliving things may not show all of these at the same time.
Which of the nonliving listed below were once apart of a living thing?
Butter, leather, wool, cooking oil, apple rubber. 
Why do living organisms need food?
Organisms that our living need energy which they get from food.
Go eat food
Categorise the following as living things or nonliving things
Dry leaves – nonliving
Ants – living
Plough – nonliving
Mushroom – living
Sewing machine – nonliving
Radio – nonliving
Boat – nonliving
Earthworm – living 
What is stimuli? Give three examples, explaining how different living organisms respond to it.
Changes in our surroundings that make us respond to them are called stimuli. Example closing the eyes automatically when someone enters a dark place.
Example, wild animals running away when bright light is flash towards them
Example in some plants like Minosa, commonly known as touch me not
Living organisms show movement. Comment.
Animals move from one place to another, and also other body movements. Plants are generally anchored in soil so that they do not show movement. However, various substances like water minerals, and the food synthesised by them.
Why is excretion important?
The process of getting rid of waste by organisms is known as excretion. Not all the food that is eaten is completely used. Only part of it is utilised by the body while the rest is removed. 
Give two vegetative structures which help to form new plants 
A part of a potato with a bird grows into a new plant (modified stem)
In roses, cutting of stem helps to form a new plant
Identify an animal which
1.provides young ones
2.lays eggs
- Cat/cow/dogs most of the mammals
- Hen/pigeon all birds
Explain with the help of suitable examples how handpicking can be used as method of seperation.
The method in which substances in a mixture can be separated by just picking them out with the help of hand from the mixture is known as handpicking.
Examples
Stones from wheat
Separating insects from rice
To superset various types of vegetables from the baskets containing mixture of vegetables.
Winnowing cannot be done in a closed room. Give reasons.
No winnowing is not possible enclosed room. The reason is that we winnowing needs wind which occurs only when air moves since there is no wind in a closed room, winnowing can take place.
How does the framer separate grains from bundles of stalks?
The famous separate green seeds from the bundles of STALKS by threshing. This stalks are beaten to free the grain seeds.
