Questions

A biosphere is the sum of all the ecosystems established on planet Earth.

An ecosystem is an area in which the plants and animals all interact to create a living environment. Therefore ecosystem is a smaller unit of earth, all ecosystems together form the earth.

The branch of biology that studies the different structures and functions of the cell is called Cell Biology or Cytology.

 A cell is the smallest unit of life that can replicate independently, and cells are often called the "building blocks of life"

Cell Biology deals with :

• Life cycle 

• Structure and organisation of cell organelles and their physiological properties. 

• Metabolic processes 

• Interactions with their environment 

• Signalling pathways.

A DVD is an example of Optical Disc.