The structures form the ultrastructure of the cell.įigure 2.9: Diagram of the cell ultrastructure of an animal cell. The diagram shows the structures visible within a cell at high magnification. photosynthesis).įigure 2.9 shows a two-dimensional drawing of an animal cell. Some functions performed by cells are so vital to the existence of life that all cells perform them (e.g. Your body contains several billion cells, organised into over 200 major types, with hundreds of cell-specific functions. You will learn more about this in the following chapter: Cell division.Ĭells are the smallest form of life the functional and structural units of all living things. The contents of cells from similar species are basically the same.ĭNA (the hereditary information of cells) is passed from 'parent' cells to 'daughter' cells during cell division.
This information is known as 'hereditary information' and is contained within DNA.
Cells contain the information necessary for the creation of new cells.Energy flow occurs in cells through the breakdown of carbohydrates by respiration.The activity of an organism depends on the total activity of independent cells.The modern understanding of cell theory extends the concepts of the original cell theory to include the following: The cell theory applies to all living things, however big or small. cells are the basic building blocks of life.new cells are created by old cells dividing into two.all living things are made of cells and their products.It is an explanation of the relationship between cells and living things. The cell theory developed in 1839 by microbiologists Schleiden and Schwann describes the properties of cells.
The differences between plant and animal cells can be linked to Grade 9. The roles of the organelles within the cells need to be introduced and relate structure and location of organelles to their function.Ĭells differ in size, shape and structure and therefore carry out specialised functions. In this section the learners now expand their knowledge and learn the various cell structures and related functions.
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