Organization of life

Organization of lifeNotice how your body is composed? You will know that it is composed of lots of small units and they cannot be seen by naked eyes. Those small units are called cells. Living things may be composed of one cell, but there are others which are composed of millions of cells. It is called multi cellular organisms.In general, tiny cells can only be seen with a microscope. A cell is the basic unit of all living things. It is the smallest part of a living thing which is fully alive.Scientists have agreed that based on the existence nucleus membrane, there are two kinds of cells. A cell without the nucleus membrane is called prokaryotic cell. The examples of this type of organism are bacteria and blue algae. Whereas a cell that has a membrane protecting the nucleus material is called eukaryotic cell. The examples are animals and green plant cells.Each cell in your body is active and has a particular duty. Activities inside a cell may be compared with 24 hour-operating machine which produces different kinds of products. This process looks like an activity inside the factory. Only materials needed are allowed to enter the factory. Ready products will be carried outside the factory.So, the function of a cell is similar to factory. All cell functions take place in a building called the cell membrane. The cell membrane covers the internal part of a cell and controls the delivery process of substances coming in and out the cell. Cell membrane helps to maintain the chemical balance inside and outside the cell. Food and oxygen are carried into the cell through the membrane, while the remains are cast outside through the membrane.Cytoplasm is a gel like material inside a cell membrane. Most of the materials inside cytoplasm are water and several chemical substances that support the life of a cell. Cytoplasm always moves and flows.

What are needed by living things?

What are needed by living things?
In hot weather it is very likely that your mouth and throat feel dry. You are thinking of having a glass of cold water. You are thirsty and your body needs water. All living things need water.When you dive, your body will show a reaction. Even though enough water is available, your body needs something else. It needs air. Water and air are two out of many things needed for living things to stay alive.All living things carry on respiration. To breath they need air. Air contains nitrogen, oxygen, carbondioxide, water vapor and other gasses. Without oxygen in the air, living things will die soon. Oxygen is also found in the water. Most organisms living in water get the oxygen that they need from water. Plants and animals need oxygen to get energy.Living things need air, water, space and food. Each living thing has differences for their food need, for example plants need light to get energy to produce food. You have noticed that living things grow and develop, respond to any stimulus and do other activities. Therefore, they need enough space to do such activities. To do these activities organisms need energy. Where do they get the energy from? Like cars which need fuel, living things also need fuel (energy) from the food.Questions:1. What are needed by living things?2. Why do living things need air?3. Why do living things need oxygen?4. What is oxygen?5. What does a plant need to get energy?6. What are the characteristics of a living thing?7. Why do living things need food?