Life and Cells for Secondary 1

1. Prepared by T. Gemma Hilado
Life and Cell for M1

2. Topic Outline
• Features of Life
• Using a Microscope
• Cell Structures
• Cell Processes: Diffusion and Osmosis
• Review Questions

3. Organism
• Each living thing is called organism.

4. Features of Life
1. Organisms are made of cells.
• Feature 1
• Feature 2
• Feature 3

6. 2. Organisms need food for energy.

7. 3. Organisms grow.

8. 3. Organisms respond to their
surroundings.

9. 4. Organisms respond to their surroundings.
Stimulus- a change in the surroundings that affects an
organism. (ex. Light, sound, odor, temperature, etc)
Response- An organism reacts to a stimulus with a
response.

10. 5. Organisms reproduce.
A. Sexual Reproduction
- Involves two parents and produces offspring that
closely resemble to the parents.
B. Asexual Reproduction
- Involves only one parent and produces offspring
that are identical to the parent.

11. Sexual reproduction in Plants

12. Sexual reproduction in Animals

13. Asexual reproduction in Plants

15. 6. Organisms adapt to the environment

16. Using a Microscope

17. Using a Microscope

18. Microscope
1.Light Microscope – magnifies
tiny organisms up to 1,000
times.-Uses light and lenses.
2. Electron Microscope –
magnifies up to a million times.-
Uses electrons.

19. Overview of Cell Structure

20. Objectives:
1. To be able to identify parts of an animal cells
and its functions.
2. To be able to difference between animal and
plant cells.
3. To be able to do Osmosis and Diffusion
experiments.

21. Cell Types
• Prokaryotic
• Eukaryotic

23. Cell Structures

24. Cell – a unit of life for all living things.
- each cell has a membrane.
Cell membrane- a thin layer that surrounds and
holds the parts of the cell together.

25. Animal Cell

26. Plant Cell

27. Organelles
• Cellular machinery
• Two general kinds
– Derived from membranes
– Bacteria-like organelles

28. Plasma Membrane
• Contains cell contents
• Double layer of phospholipids & proteins

29. Cell Walls
• Found in plants, fungi, & many protists
• Surrounds plasma membrane

30. Nucleus
• Control center of cell
• Double membrane
• Contains
– Chromosomes
– Nucleolus

31. DNA
• Hereditary material
• Chromosomes
– DNA
– Proteins
– Form for cell division
• Chromatin

32. Nucleolus
• Most cells have 2 or more
• Directs synthesis of RNA
• Forms ribosomes

33. Endoplasmic Reticulum
• Helps move substances within cells
• Network of interconnected membranes
• Two types
– Rough endoplasmic reticulum
– Smooth endoplasmic reticulum

34. Rough Endoplasmic Reticulum
• Ribosomes attached to surface
– Manufacture proteins
– Not all ribosomes attached to rough ER
• May modify proteins from ribosomes

35. Smooth Endoplasmic Reticulum
• No attached ribosomes
• Has enzymes that help build molecules
– Carbohydrates
– Lipids

36. Mitochondria
• Have their own DNA
• Bound by double membrane

37. Chloroplasts
• Derived form photosynthetic bacteria
• Solar energy capturing organelle

38. Cells
White Blood CellsRed Blood Cells