1. Where do Living Things Come From?
Early theory -
Spontaneous generation: living things can come from nonliving materials.
Ex – rats from grain stored in dark room
- maggots from rotting meat

2. Discovery of Cells By Robert Hooke in 1665. Made a simple microscope.
Looked at cork cells. Only saw cell walls.
Named them after the rooms or “cells” of a monastery.

3. Led to the Cell Theory All living things are made of cells.
A cell is the basic unit of structure and function in a living thing.
Cells only come from other cells.

4. Modern Compound Microscope
Instrument for observing small objects
Magnify images up to 2000X their size

5. Introduction to Cells Cells are the basic units of organisms
Cells can only be observed under microscope
Basic types of cells:
Bacterial Cell
Animal Cell
Plant Cell

6. Number of Cells Organisms may be: Unicellular – composed of one cell
Multicellular- composed of many cells that may organize

7. Cells May be Prokaryotic or Eukaryotic
Prokaryotes are bacterial cells.
Very simple They lack a nucleus or membrane-bound structures called organelles
Eukaryotes include most other (plants, fungi, & animals)
Complex cells
They have a nucleus and membrane-bound organelles
Cells May be Prokaryotic or Eukaryotic

8. Prokaryotes Nucleoid region contains the DNA Cell membrane & cell wall
ONLY ORGANELLE: Ribosomes, which make proteins.
These are tiny structures that are NOT covered with membranes

9. Eukaryotic Cell Contain 3 basic cell structures: Nucleus Cell Membrane
Cytoplasm with organelles

10. Two Main Types of Eukaryotic Cells
Animal Cell
Plant Cell

11. Organelles – “Tiny Organs”
Cell structures that make it possible for cells to carry out all life functions
Can only be observed under a microscope
Have specific functions
Found throughout cytoplasm
Most are surrounded by a membrane

12. Control Organelle Nucleus Controls the normal activities of the cell
Bounded by a nuclear membrane
Contains chromosomes

13. Nucleus Each cell has fixed number of chromosomes that carry genes
Genes determine which proteins a cell will make.

14. Nucleus surrounded by a membrane
Similar in structure to the cell membrane – made of phospholipid bilayer
Similar in function – controls what enters and leaves nucleus

15. Nucleolus Cell may have 1 to 3 nucleoli Inside nucleus
Cannot be seen when cell divides
Makes ribosomes that make proteins

16. Smooth & Rough Endoplasmic Reticulum – long tubes
Rough ER has ribosomes on its surface & makes proteins to EXPORT
Smooth ER lacks ribosomes & makes proteins that are used in the cell

17. Golgi Bodies Stacks of flattened sacs
Have a receiving side (closest to nucleus) &
a shipping side Receive & modify proteins made by RER
Transport vesicles with modified proteins pinch off the ends
Transport vesicle

18. Lysosomes Contain digestive enzymes
Break down food and worn out cell parts for cells
Programmed for cell death (lyse & release enzymes to break down & recycle cell parts)

19. Cell Powerhouse Mitochondrion ( mitochondria ) Rod shape organelle
Site of Cellular respiration:
Changes sugars to energy of ATP

20. Mitochondria
Active cells like muscles have more mitochondria than other cells

21. ATP supplies energy for all of a cell’s activities

22. Surrounding the Cell Cell membrane
Lies immediately against the cell wall in plant cells
Made of protein and phospholipids
Selectively permeable

23. Cell or Plasma Membrane
Cell membrane
Living layer
Controls the movement of materials into and out of the cell
Selectively permeable

24. Proteins in the cell membrane - a. transport material across membrane b. serve as attachment sites for molecules

25. Cell membrane is a phsopholipid bilayer. Hydrophilic end – outward.
Hydrophobic end - inward

26. Cytoplasm of a Cell Cytoplasm
Jelly-like substance enclosed by cell membrane
Provides a medium for chemical reactions to take place

27. Cytoplasm
Contains the organelles

28. Special Plant Cell Organelles
Chloroplast
Contains the green pigment chlorophyll
Traps sunlight to make to make sugars (food)
Process called photosynthesis

29. Plant Cell
Cell wall
Dead layer
Made of cellulose
Freely permeable

30. Plant Cell
Cell wall
Protects and supports the enclosed substances (cytoplasm)
Prevents entry of excess water into the cell
Give shape to the cell

31. Plant Cell Organelles Vacuole Plants have a large central vacuole
Contains cell sap:
Water, sugars, proteins, minerals, wastes, & pigments

32. Different kinds of plant cells –specialized for different jobs
Onion Epidermal Cells
Root Hair Cell
root hair
Guard Cells

33. Animal cell No cell wall, no large central vacuole, and no chloroplast
cytoplasm
No cell wall, no large central vacuole, and no chloroplast
nucleus
mitochondrion
cell membrane
glycogen granule

34. Organelle Unique to Animal Cells
Near the nucleus
Paired structures
Help cell divide

35. Different kinds of animal cells
white blood cell
red blood cell
cheek cells
sperm
nerve cell
muscle cell
Amoeba
Paramecium

36. Similarities between plant cells and animal cells
Both have a cell membrane surrounding the cytoplasm
Both have a nucleus
Both contain mitochondria and other organelles

37. Differences between plant cells and animal cells
Relatively smaller in size
Relatively larger in size
Irregular shape
Regular shape
No cell wall
Cell wall present

38. Differences between Plant Cells and Animal Cells
Vacuole small or absent
Large central vacuole
Nucleus at the center
Nucleus near cell wall

39. The cell is the Basic Unit of Life
Unicellular organisms are made of one cell only
The cells of multicellular organisms are specialized to perform different functions
e.g. mesophyll cells for photosynthesis and root hair cells for water absorption

40. Levels of organization
Cells are grouped together and work as a whole to perform special functions

41. Tissue A group of similar cells to perform a particular function
Animals : epithelial tissue, muscular tissue
Plants : vascular tissue, mesophyll

42. Organ
Different tissues group together to carry out specialized functions
Heart : consists of muscles, nervous tissue and blood vessels
Leaf : consists of epidermis, mesophyll and vascular tissue

43. The Structures of a Leaf (Plant Organ)
Chloroplast
Palisade Mesophyll Cell
Spongy Mesophyll Cell
Air Space
Stoma

44. The Structures of a Heart (Animal Organ)

45. System
Several organs and tissues work together to carry out a particular set of functions in a co-ordinated way
Human : digestive, respiratory, excretory, circulatory and reproductive systems
Plant : root and shoot systems

46. Human Body Systems Examples of systems : Digestive System
Respiratory System
Circulatory System
Nervous System
Reproductive System

47. Levels of Organization
CELLS (muscle cells,nerve cells)
TISSUES (muscle, epithelium)
ORGANS (heart, lungs, stomach)
SYSTEMS (circulatory system)
ORGANISM (human)

48. It’s You!