Answer No 1:
Cell can be described as the basic unit of organization of all living things. All living things, whether prokaryotes or eukararyotes, will be made up of a cell or different cells. Prokaryotes are one- celled whereas eukaryotes are made up of many cells.
Answer No 2:
A group of tissues which work together make up an organ whereas, group of organs which work together will make up an organ system.
For example, the organs such as the heart, the lungs, the liver, the kidneys etc are made up of different tissues which work together so that these organs can perform their prescribed functions.
Answer No 3:
Different organs work together in an organ system so that an organ system can perform its functions.
For example, in the circulatory system, the heart, capillaries, veins, arteries work together so that they can provide transport blood.
Answer No 4:
Different tissues perform different functions. Different tissues will work together to make organs of an organ system. These organs will work together to make the organ system perform its function.
Answer No 5:
Every organ of an organ system has a vital role to play for the proper functioning of the organ system. Malfunction of any of the organs will result in the functions being not performed. For example, the function of the heart is to pump blood. If the heart stops working then the circulatory system will not be able to transport oxygen.