Name two cell-organelles that are double membrane bound. What are the characteristics of these two organelles ? State their function and draw labelled diagrams of both.
 Chloroplasts and mitochondria are organelles which have double membrane . 

Mitochondria - is called the power house of the cell as it produces cellular energy in the form of ATP. It is bounded by two membrane, the inner membrane forms inner foldings called cristae. The matrix has a single circular DNA molecule. 

Chloroplasts - are also double membrane bound organelles which help to trap the solar energy and produce food. The stroma contains many flattened disc like structures called thylakoids which are arranged in stacks to gorm grana. The chloroplasts consists of the pigment chlorophyll that helps to convert sun's energy to chemical energy. 

Functions of :

Mitochondria - It produces the cellular energy in the form of ATP.

Chloroplasts - trap the energy of the sun and produce food.