Points to Remember
• Cell is the basic structural and functional unit of living organisms. All living organisms are made up of cells.
• Cells vary in shapes and size. The size of a cell is measured in micrometers (µm).
• Cells are combined together to form tissues. The tissues are combined together to form organs. Many organs are combined together to form the organ system.
• The sense organ eye is concerned with vision.
• Respiration is the process in which energy is released while food is oxidised. It consists of external respiration and internal respiration (cellular respiration).
• There are two types of respiration depending upon the availability of oxygen. They are aerobic respiration and anaerobic respiration.
• Selective permeability of plasma membrane enables the cell to maintain homeostasis.
• Diffusion involves movement of molecules from the region of their higher concentration to the region of their lower concentration which can occur without a semi permeable membrane.
• Osmosis involves movement of solvent molecules from the region of their higher
concentration to the region of their lower concentration which can take place through a semi permeable membrane.
• Homeostasis is the maintenance of a constant internal environment of the body.
• Metabolism involves release and utilisation of energy or energy exchange within the organisms. It can be divided into two categories namely anabolism and catabolism.
• The repeated anabolic and catabolic reactions in the metabolic process maintain the homeostatic condition of the body.
1. Alveoli Tiny air sacs of the lungs which allow for rapid gaseous exchange.
2. Eukaryotic An organism having cells each with a distinct nucleus within which the genetic material is contained.
3. Organelles Specialized structures within a cell that perform a specific function.
4. Micron Small unit of measurement that measures length which is one thousand of a millimetre.
5. Haemoglobin Iron containing red pigment of red blood cells of vertebrates, which gives red colour to blood.
6. Prokaryotic Typically unicellular microorganism that lack a distinct nucleus and membrane bound organelles.
7. Diaphragm The muscle that separates the chest (muscle) cavity from the abdomen.
8. Pleura Protective covering of the lungs.
9. Metabolism The sum of all chemical reactions by which living organisms sustain their life.
1. The Science of Biology - Raven, Johnson. McGraw Hill.
2. Histology and Cell Biology - Kierstenburm
3. Elsevier’s Dictionary of the Genera of life
4. Cell Biology Organelle Structure and function.
1. h t t p s : / / s c i e n c i n g . c o m / l e v e l s - organization-biology-8480388.html
2. http://www.biologyreference.com/Gr-Hi/ History-of-Biology-Cell-Theory-and-Cell-Structure.html
3. http://www.biologyreference.com/A-Ar/ Animalia. html