BIOLOGY MADE EASY - 6th Standard

BIOLOGY MADE EASY

Define Soil Profile

A vertical section of soil from surface down to the bedrock showing different layers (horizons) is call soil profile. A soil profile visually shown 03 regions

1)    A - Horizon

2)    B - Horizon

3)    C - Horizon

Define Fertilization

The fusion of male cell with the female cell (or egg cell) is called fertilization.

Define Node

The point on the stem from where the leaves and branches arise is called a node.

Define Weathering

The process of breaking down of huge pieces of rock and its minerals in fine particles by the physical, chemical and biological agents is called weathering. Depending upon the natural agents involved, weathering can be classified into 3 types:

1)    Physical weathering

2)    Chemical weathering

3)    Biological weathering

Define Lamina

The thin, flat and extended part of the leaf which is mostly green in color is called lamina.

Define Afforestation

The planting of more trees to reduce the loss of fertile top layer of soil is called afforestation.

One word for unweathered parent rock present below the C-horizon is Bedrock.

One word for the part of the flower that develops into seed is Ovule.

Largetst particle of soil is called as gravel.

The stalk that joins leaf to the stem is known as Petiole.

The part of the plant above the soil is called Shoot System.

Did you know that the leaves of Opuntia are reduced to pointed structures called spines to provide protection and reduce loss of water.

Why is clayey soil not very suitable for the growth of plants?

This type of soil is not very suitable for the growth of plants because water occupies the whole space between the particles as it has high water holding capacity and it becomes difficult for plants to respire due to lack of oxygen.