Cell as a unit of life

Cell as a Unit of LifeObjectiveidentify that cell is the basic unit of living things,Identify, draw, label the general structures of animal cells and plant cellsstate the function of each cell structure,state the similarities and differences between an animal cell and a plant cell.What is cellCell as a unit of lifeAll living organism are made up of cellsCells are the smallest living parts in a living thingCell is microscopic and could only be observed by microscope.Some living things are very simple. They are made up of only one cell.Some living things are very complex. The human body is made up of 50 to 60 trillion cells.

Cells are very small. We cannot see them with the naked eye.We need the help of a microscope to see cells.A microscope is a tool that enables us to look at small things which cannot be seen with the naked eye.A microscope is very expensive. It must be handled with care.Plant cellStructure of cellFunctionNucleusControl all activities of the cellVacuolesStores salt and sugar solutions, hold waste substancesCytoplasmA place where all chemical reactions take placeCell membrane Control the movement of substances into or out of the cell Cell wall Support and gives the cell a regular shape ChloroplastsA place where plants make food by photosynthesis. Contain chlorophyll which is used to trap sunlight for photosynthesis.

Animal cell

Comparing Animal Cell and Plant Cell Differences Functions Of Cell StructuresEvery cell structure performs a function for the cell.The function of a chloroplast is to carry out photosynthesis to make food for the plant.Only cells that contain chloroplasts can carry out photosynthesis. The cells in a plant root for example, cannot carry out photosynthesis.The nucleus can control all activities of the cell because it contains chromosomes. Chromosomes carry genetic information that control the cells activities.The cell membrane is the structure that controls what substances move into or out of the cell.Food passes through the cell membrane before it enters the cell.Waste materials pass through the cell membrane before they leave the cell.The cell wall is a strong structure that gives the plant cell a regular shape . The animal cell does not have a regular shape because it does not have a cell wall.Unicellular and Multicellular OrganismsObjectiveState the meaning of unicellular and multicellular organismsGive examples of unicellular and multicellular organisms

UnicellularUni means oneCellular - cellUnicellular organisms are vey small.Need microscope to view themExample

MulticellularMulti - more than oneCellular - cellExample of multicellular organismsHydra, insects birds and fernsExample of microorganismsMucor and Spirogyra

Cell in human body

Organisation of cellsSystems of the human bodySystemFunctionDigestive systemTo digest food so that it can be absorbed easily and used by the bodyNervous SystemTo help the body respond to changes inside and outside the bodyRespiratory systemTo enable gas exchange to take placeReproductive systemTo produce reproductive cellsBlood circulatory systemTo carry oxygen and food to all parts of the ody and waste substances to the kidneysSkeletal systemTo support the weight of the body and protect soft organExcretory systemTo remove toxic substances from the bodyMuscular systemTo help the body to moveLymphatic systemTo defend the body against disease with the help of lymphocytesEndocrine SystemTo produce hormones to control the bodys activities and developmentConclusion