Presentation on theme: "Cells Mr Heffernan. Cells What are cells? – Cells are the basic building blocks of living thing. Can we see cells with our eyes? – No, we need to use."— Presentation transcript:
Cells What are cells? – Cells are the basic building blocks of living thing. Can we see cells with our eyes? – No, we need to use a microscope because they are too small. How are new cells formed? – New cells are formed by a process called cell division. Do animal and plant cells have the same structure? – No, some of the parts are the same but plant cells have a cell wall animal cells do not.
Cell Division Cells can divide to form two identical cells. This process is called Cell Division. Cell division allows living things to grow. Humans grow from a single cell called a zygote by cell division. One Cell divides To form two identical cells
Animal Cells Animal cells have three main parts – A cell membrane – A nucleus – Cytoplasm The cell membrane is a very thin layer surrounding the cell. The nucleus is the control centre of the cell. Cytoplasm is a watery fluid between the nucleus and the cell membrane. Cell membrane Nucleus Cytoplasm
Plant Cells Plant cells also have a cell membrane, a nucleus and cytoplasm. Plant cells also have a cell wall. The cell wall is found outside the cell membrane in plant cells. Cell membrane Cytoplasm Nucleus Cell Wall
Tissues Plants and animals contain many different types of cells. Cells on the inside of your cheek are very different from red blood cells. A group of similar cells which carry out the same function are called Tissues.
Examples of Tissues Tissues are a group of cells which carry out the same function Red blood Cells Bone Cells Cheek Cells
Organs A structure that contains two or more tissues working together is called an organ. Some examples of organs are ―Lungs ―Heart ―Brain ―Kidneys ―Leaves ―Roots Is this what a heart looks like? NO! It looks more like this and it is about the size of your closed fist
Systems A system is a number of organs working together. Examples of systems in the human body are —The respiratory system —The digestive system —The reproduction system For more information on the digestive system follow the link http://www.daviddarling.info/encyclopedia/D/digestive_system.html http://www.daviddarling.info/encyclopedia/D/digestive_system.html
CellsTissuesOrgansSystemsOrganisms An organism is a living thing. Organisms are composed of a number of systems. These systems work together to allow the organism to function properly and stay alive Organisms are organised as shown below