Class 3 NSO : Soil types

What is soil

Soil is formed by erosion that is breaking up of rocks , by the action of sun, wind and rain. It forms at the surface of land and  is the “skin of the earth.” Soil is capable of supporting plant life and is vital to life on earth.

Soil contains a lot of different things;  a few essential ingredients are listed below:

Sediment Every soil contains some mixture of sediments.  The three main sediments are sand, silt, and clay. The type of sediments  determines a soil’s typeIdeal soils (for farming) are a mixture of the three. 

Organic Matter – Soil contains a lot of partially decomposed organisms which is called organic matter. Microbes in the soil break it down to make important nutrients. Most organic matter comes from plants. This is also called Humus and is dark brown or black in color.

Minerals – There are tons of different minerals in the soil. They’re used by plants for growth. When plants die, their minerals return to the Earth.

Types of soil and properties

 

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Class 3 NSO : papers

Grade 3 NSO papers

 

nso-ieo-imo-nco

nso-ieo-nco-imo

nso-ieo-imo-nco

nso-imo-ieo-nco

NSO_1

Grade3NSO_2

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Grade 3 Science (NSO) : Earth and Universe

A look at the previous lessons on earth and universe :

Grade 2 Science (NSO) : Earth and universe

Weather and The Sky: Earth and Sky fundamentals

Earth’s Revolution

The motion around the sun along its orbit is called a revolution . The amount of time it takes for a single trip around the sun is called a period of revolution. The period for the Earth to revolve around the sun is 365.24 days or one year. The .24 days is why every four years February has 29 days.

There are 4 seasons in an year .In Autumn and Spring the northern and southern hemispheres are tilted equally toward the sun.In Summer the Earth is on the other side of the sun and the northern hemisphere is tilted  toward the sun and gets better sun rays. In winter the northern hemisphere is tilted away from the sun. That’s how we get seasons.

Earth’s orbit around the sun is slightly elliptical, Earth is actually slightly closer to the sun in the winter than it is in the summer.It is the tilt of Earth’s axis that causes the seasons.

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Grade 3 Science(NSO) : Human body part 2

We have already covered Skeletal, immune, cardiovascular, muscular and integumentary system in part 1.

Grade 3 Science (NSO) : Human body part 1

Lymphatic system :

It is responsible for the removal of interstitial fluid from tissues. It absorbs and transports fatty acids and fats as chyle from the digestive system. It transports white blood cells to and from the lymph nodes into the bones.

-picks up fluids leaked from the capillaries
-supports immune systems: houses white blood cells
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Grade 3 Science (NSO) : Food part 3 – Preservation of food

Food Decay and Preservation

Bacteria and fungi are the main groups of  decomposer organisms. Food decay is also known as food spoilage.

Bacteria and fungi need Food , Warmth and Moisture to grow.

There are several ways to stop or slow down the decay of foods. This is known as Food Preservation.

 

Food preservation methods

 Freezing

Bacteria cannot reproduce at low temperatures.

Bacteria and fungi need warmth to grow. In low temperatures they stop growing.

Following is the list of food preserved by freezing;

  • Meat
  • Fish
  • Fruits
  • Vegetables
  • Fresh foods
  • Cooked foods

Drying

Removing water prevents the microorganisms from growing, or digesting the food.

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Grade 3 Science (NSO) : Food Part 1 – Food Types

A look at the grade 2 lesson

Grade 2 Science(NSO) : Food

Food can be divided into three types

Energy giving food

Give us energy to work. They contain carbohydrate and fats.

Carbohydrates

They are found in foods like rice, pasta, cassava, yam etc. when starchy foods are eaten and digested, simple sugars like glucose are obtained. It is this glucose that the body uses for energy.

There are two major types of carbohydrates:

1. Simple carbohydrates (Sugar)

  • Fruits
  • Milk
  • White sugar you would find in a sugar bowl
  • Chocolates

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Grade 3 Science (NSO) : Birds

Bird, a warm-blooded vertebrate that lays eggs and has feathers and wings.

Type of beaks

 

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Grade 3 Science (NSO) : Flower, fruit and seed

Before starting lets take a look at the Grade 2 lessons

Plant – Types of plants

Plants – Parts we eat

Plants: Fruits

Plants : Uses of different plants

Flower

Responsible for reproduction

Colour and fragarence of flowers attract insects who act as pollinators.

Flower parts that we eat :

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Grade 3 Science(NSO) : Leaf

Functions of a leaf

Absorbs sunlight

Help in exchange of gases

Carries out photosynthesis

Apex : Tip of leaf

Base : Attaches to petiole ; if petiole is absent attaches directly to stem

Margin : Edge of leaf

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Grade3 Science (NSO) : Plants :Roots

Plants :Roots

Root

Root is the underground part of the plants body. It fixes the plant within the soil and absorbs water and mineral nutrients from the soil. It also stores excess food.

Function of roots

  • Roots attach the plant body to the ground. It provides support to the plant and helps in holding the plant firmly in the ground.
  • Root hairs of the plant absorb water and mineral from the soil and pass it to the stem.
  • Some roots like carrot, radish etc. store food.
  • Root bind the soil which otherwise may be blown away by wind or washed away by water. Root prevents soil erosion.

Types of roots

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