Cell, tissue, organ, organ system, organism

Question 1 What is a cell?

Question 2 What is the function of muscle cell?

Question 3 What is the photosynthetic cell?

Question 4 What are tissues?

Question 5 What is the function of muscle tissue?

Question 6 What is the function of photosynthetic tissue?

Question 7 What are organs.Name few organs?

Question 8 What is the function of heart?

Question 9 What is the function of stomach?

Question 10 What is the function of brain?

Question 11 What is the function of lungs?

Question 12 What is the function of roots?

Question 13 What is the function of stem?

Question 14 What is the function of leaves?

Question 15 What is the function of flowers?

Question 16 What is an organ system?

Question 17 Give 2 example of organ system in animals?

Cell

Cell is the smallest unit of life which has a definite structure and perform a specific function.There are many different shapes and sizes.Most of the cells are specialised to perform different function.They are called specialised cells.

Muscle cells are specialised to contract and relax so that they can bring about movement in body parts.

Photosynthetic cells are specialised to carry out photosynthesis and make food.There are many types of specialised cells in animals and plants which perform different functions.

Tissues

The group of similar cells which work together to perform a particular function is called tissue.

A multicellular organism is made up of millions of cells.The cells in multicellular organism do not work as single cells, they work in groups of similar cells.

Muscle tissue is a group of muscle cells joined together which is specialised to contract and relax so as to move body parts.

Photosynthetic tissue is a group of photosynthetic cells joined together which is specialised to do photosynthesis and make food.There are many types of tissue as there are cells.

Organs

An organ is a collection of different tissues which can work together to perform a particular function in the body of an organism.

The different tissue combine together to form organs.These organs perform different tasks for the animals or the plants.

The multicellular organism are made up of many different organs which do different jobs for the organism.

Some of the organs which are found in the bodies of animals are heart, stomach, lungs, brain, kidney, eyes, mouth, hands etc.

The function of heart is to pump blood around the body.

The function of stomach is to digest food.

The function of brain is to control all the parts of a body.

Lungs are the organs of breathing.The function of lungs is to take in oxygen and give out carbon dioxide.

The various organs found in the body of a plant are roots, stem, leaves, flower, fruits.

Roots absorb water and dissolved mineral salts from the soil.

Stem carries water and mineral from the roots to the leaves, and the prepared food from the leaves to other parts of the plants.It holds branches and leaves.

The leaves prepare food for the plant by the process of photosynthesis.

The flowers are the reproductive organs which lead to the formation of fruits and seed.The fruit protects the seeds.

Organ system

A group of interconnected organs which work together to do a big job for the organism is called organ system.

All the multicellular animals and plants have many organ system in their bodies to carry out various life processes.

For Ex:Digestive system, circulatory system, muscular system, skeletal system, excretory system etc.

The function of digestive system is to break down the food into simple substance which can be absorbed by the body.The main organs of the digestive system are:Mouth, food pipe, stomach, small intestine, large intestine, rectum, anus.Each organ of digestive system perform a different function such as ingestion, digestion, absorption, assimilation and egestion.

The plants have 2 main organ system:Root system and shoot system.The root system consist of various types of roots whereas shoot system is made up of organs like stem, leaves, flowers, fruits.

Organism

An organism is an animal or plant which can exist on its own.

An organism is made up of many different organ system which work together to perform all the functions necessary for maintaining .

For Ex:Human being is an organism.It is made up of many different organ system.All the organ system work together to make man a living organism.

A cat, dog, neem tree, mango tree, rose plant are all organism which are made of many different organ systems working together.