Cells are the basic unit of structure and function in living organisms. The key components of cells include the nucleus, cytoplasm, cell membrane, and in plant cells cell walls, vacuoles, and plastids. Cells divide through mitosis to grow and reproduce. As cells become specialized through division of labor, they develop distinct shapes and chemical functions to perform roles like conducting nerve impulses, absorbing water and minerals in roots, moving mucus in the lungs, or transporting nutrients in plants. Tissues are groups of similar cells that work together, such as muscle or gland tissues. Organs are composed of multiple tissue types organized to perform a specific function, and organ systems integrate to keep the whole organism alive.

1. Cells and Tissues

2. 1.Cell Structure
• Cell: a box like structure present in
animals and plants.
• Photomicrographs: photograph of
cells through microscope.

3. Section
• Sections: The slices of specimen of
specimen to be examined.
– Longitudinal section: along the length.
– Transverse section: cross the specimen.

4. How to examine specimen?
1. Razor Blade and specimen is being
cut directly (Plant Cell).
2. Soaked in wax before being cut
(Animal Cell).
3. Sections are treated with dyes
called “stains”.

5. Standard structure of cells
• Nucleus
• Cell membrane
• Cytoplasm
All cells have these structures

6. Cytoplasm
• Many particles in the cytoplasm perform
particular tasks, they are called organelles.
• Cytoplasm: Jelly like structure inside the cell.
• Ribosomes: Build up cell protein.
• Mithocondria: Generate energy for the cell’s
living process.
• Contain enzymes either in cell membrane of
in cytoplasm.
• Made by lipids and proteins.

7. Cell Membrane
• A thin layer of cytoplasm around the
cell.
• Control the substance enters and
leave the cells.
• Made of lipids.
• Good substance enter, bad substance
leave and stay outside.

8. Nucleus
• Absorb stain more than cytoplasm.
• Contain chromosomes.
• Control type and amount of enzyme
produced.

9. Mithocondria
• Most numerous in region of rapid
chemical activity.
• Responsible for providing energy
from food substance.
• Present in both animal and plant
cells.

10. Plant Cells
• Cell Wall
• Vacuole
• Plastids
Additional structure present in
Plant Cell

11. Cell Wall
• Not as selective as Cell membrane
• Behind, there is cell membrane that
attached to the cell wall.
• 2 cells share the same cell wall.

12. Vacuole
• Contain cell sap.
• Give pressure to outside.
• Contain sugar
• Animal cell have vacuole but only in
small amount, this is because they
they have particular job and not
permanent.

13. Plastids
• Organelles that found in plant cells
but not in animal cells.
• Store food.
• If contain green pigment chlorophyll
it’s called chloroplast.

14. 2. Cell division and cell
specialization
• When a cell are develop to do
specific task, it becomes specialized.
• Growth is the result of cell division
and the enlargement of a cell.
• Cell which have ability to divide are
called stem cells.

15. Process of cell Division in
Animal cells
1. Nucelus Divide
2. Cytoplasm pinch off the nucleus
3. They divide completely and one of
the cell may be specialized and the
other one may retain the ability to
divide.

16. Process of cell division in plant
cells
1. A plant cell about to divide has a large
nucleus and no vacuole.
2. The nucleus divides first and new cell
wall develops and separate the two
cells.
3. Cellulose added to the cell wall.
Vacuoles form in one of the cell.
4. This vacuole join to form larger
vacuole. This takes in water and the
cell swell. The other one will retain
ability to divide again.

17. Specialization of Cells
• Most cells, when they have finished
dividing and growing become
specialized.
This means that:
1. They do one particular job
2. They develop a distinct shape
3. Special kinds of chemical reactions
take place in their cytoplasm.

18. Nerve cells
• Conduct electrical impulses to and
from the brain.
• Some of them are very long and
connect distant parts of the body to
the spinal cord and brain.
• Their chemical reaction cause
impulses to travel along the fibre.

19. Root hair cells
• Absorb water and mineral salts from
the soil.
• The hair like projection penetrates
between soil particles and offers a
large surface area.
• The cell membrane is able to control
which dissolved substance enter the
cell.

20. Ciliated cells
• Found in the lining of trachea.
• Have a cytoplasmic hair called cilia.
• Flicking movement move the mucus
upward and carries dust and bacteria
away from the lungs.

21. White Blood Cell
• Found in bloodstream.
• Engulfing bacteria.
• It is able to change it’s shape and
move about.

22. Phloem Cell
• The point at which 2 cells meet have
several holes and this is the path for
food to pass. Through this point
cytoplasm from one cell also
communicate with others.

23. Root hair cells
• Use to absorb water and minerals.

24. Nerve cells
• Specialized in conducting impulses of
an electrical nature along the fibre.

25. Specialization of cells
• Specialization of cells can also refer
to division of labour.
• Function of organelles can also being
said as division of labour.

26. 3. Tissues and Organs
• Some microscopic animals only have
1 cell.
• A cell cannot survive by itself.

27. Tissues
• Made of hundreds same type of cells.
• Each tissues have it’s own function.

28. Epithellium Arrangement
• Ex: lining of mouth cavity
• Protect organs from physical and
chemical damage.

29. Tube arrangement
• Carries liquid from one place to
another place.

30. Muscle tissues
• Contraction of this kind of tissues
help to move food along the food
canal or to close down small blood
vessels.

31. Gland arrangement
• Make chemicals which are released
into the central space.

32. Organs
• Consist of several tissues group
together.

33. System
• Consist of organs

34. Organism
• When all organs work together to
make 1 independent plant or animal