Everything Life Sciences Grade 10

Project: Diagrams of cells

Diagrams of the cell are very well understood but they often give us the wrong impression

about how complicated cells really are. Learners are to do an assignment that will help you

understand the complexity of cells.

1. Learners are to find and submit a hard copy of 5 micrographs showing different cell
   organelles.


2. Of the five, learners must draw and label two so that they can demonstrate your draw-
   ing, labelling and interpretive skill.

Pay close attention to the following:

• the organelles should each comfortably occupy an A5 page


• the organelles must each have a heading that includes the view, title and magnification.


• Drawings must follow the drawing skills you have learnt. One drawing must be the
  same size as the micrograph, the other must be exactly half the size. Learners’ drawings
  must have a correct scale line.


• Learners must state the source of your micrographs according to the Harvard conven-
  tion.


• Marks will be awarded for neatness: present your work as a uniform set.


• Learners must select hardcopies well so that they can be easily recognisable and of
  high quality. Their images may be of the same organelle but only if the images show
  some significant variation.

Marks : [30]

Due Date:

Presentation:

3.5 Summary DUMMY

The discovery of cells:

• All living organisms are made of cells.


• Cells are very small therefore magnifying instruments such as lenses and microscopes
  are used to view them.


• By using a light microscope the simple features of cells can be studied. The light
  microscope uses a beam of light focused by various glass lenses.


• Electron microscopes have higher power of magnification than the ordinary light mi-
  croscope, therefore allowing us to see very small structures inside the cells. These
  microscopes use a beam of electrons focused by electromagnets to magnify objects
  instead of light rays and lenses.


• Robert Hooke (1665) used a light microscope to examine non-living cork cells.


• Antonie van Leeuwenhoek was the first person to observe living cells using a micro-
  scope.


• The development of cell theory was from the study of microscopic cells.

Chapter 3. The basic units of life 91