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Humus – What is it? | NCERT Science Class VII | Chapter 17 | (Gujarati Explanation for Eng Medium)

Humus is formed by decomposers such as bacteria, fungi, beetle, ants etc which falls under the saprotrophs. These decomposers decomposes or degrades the dead matter fallen on the forest floor such as leaves, plant parts, fruits, dead animal remails, fecal matter etc and converts it into dark colored substance. This dark color substance is called Humus.

Humus forms the top layer of the soil. It is very rich in nutrients. Eventually it gets absorbed by roots of plants from soil and therefore, it increases the soil fertility.

Remember: Based on how animals, plants and organisms obtain their food, they are divided into different categories such as autotrophs, heterotrophs and saprotrophs.

Saprotrophs : (sapro = dead); feeds on dead or decaying matter; e.g: yeast, bacteria, fungi, mushroom, beetles, ants, insects

This video explains what is humus from the chapter 17 of NCERT science class VIII in Gujarati for English medium.

Forests: Our Lifeline | Part 1 | Forests, Shrubs, Herbs, Creepers & Climbers

NCERT Science Class VII | Chapter 17 | Forests: Our Lifeline (Gujarati Explanation for Eng Medium) 2

Herbivores, Carnivores & Omnivores | Autotrophs, Heterotrophs & Saprotrophs | NCERT Science Class VII

You can find this chapter online on NCERT e-book here : NCERT Science Class VII Chapter 17.

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NCERT Science Class VII | Chapter 17 | Forests: Our Lifeline (Gujarati Explanation for Eng Medium) 2

This video explains about CROWN, CANOPY and UNDERSTOREY from NCERT science class VII chapter 17. It explains in Gujarati with english terms.

What is crown, canopy and understorey in forest?
Forests serve as green lungs and water purifying system in nature.

CROWN : it is the branchy part of the tree above the stem. Crowns are of different size and shape & different trees have different types of crown.

CANOPY : branches of the tall trees looks like a roof over the other plants in the forest. This structure formed by individual tree crowns in a forest is called canopy. It stops sunlight and rainwater from directly falling on the forest floor.

UNDERSTOREY : It is the level below the canopy. Plant layers growing beneath the forest canopy such as small trees, shrubs, herbs, grasses etc. forms understorey. It receives less sunlight than forest canopy.

00:05 introduction

00:34 Crown of the tree

02:44 Canopy of forests

06:05 Understorey in forests

Have you seen the part one of this chapter? Forests: Our Lifeline | Part 1 | Forests, Shrubs, Herbs, Creepers & Climbers

You can find this chapter online on NCERT e-book here : NCERT Science Class VII Chapter 17.

If you want learn Genetics visit this page.