KEY CONCEPT Cells are the Basic unit of life. Macrophages- play an important role in your immune system- take in a digest foreign materials (red= bacteria)

The cell theory grew out of the work of many scientists and improvements in the microscope. Many scientists contributed to the cell theory. Concluded that ALL living things are made of cells Proposed that all cells come from other cells First to identify cells and named them Made better lenses for microscopes First to note that plants are made of cells

Robert Hooke In 1665 he used the three-lens compound microscope to examine thin slices of cork He observed that cork is made of tiny, hallow compartments These compartments reminded Hooke of small rooms found in monasteries (where monks live), so he named them cells.

More was learned about cells as microscopes improved.

Cells Red blood cells cork

How does the size of a cell in a blue whale compare to the size of the cell in a tadpole?

How does the size of a cell in a blue whale compare to the size of the cell in a tadpole? A: Most cells in a whale are the same size as in a tadpole! So what makes a blue whale so much bigger? A whale has far more cells.

The Cell theory has three principles. 1. All organisms are made of cells.

2. All existing cells are produced by other living cells.

3. The cell is the most basic unit of life.

One of the 3 principles of cell theory is that ALL existing cells are produced by other existing cells. Apply this principle to a cut on your arm. (Explain what is happening throughout the healing process)

Messages are sent to skin cells to replicate Answer One of the 3 principles of cell theory is that ALL existing cells are produced by other existing cells. Apply this principle to a cut on your arm. You get a cut You start to bleed You form a scab Messages are sent to skin cells to replicate Skin cells replicate through mitosis New skin cells are created Scab falls off You are healed!

All cells share certain characteristics Cells tend to be microscopic. All cells are enclosed by a membrane. All cells are filled with cytoplasm. cell membrane Bacterium (colored SEM; magnification 8800x) cytoplasm

Draw and label picture on top of p. 24 There are two cell types: eukaryotic cells and prokaryotic cells. Eukaryotic cells have a nucleus. The nucleus holds the DNA Have membrane-bound organelles May be multi-cellular or single-celled organisms nucleus organelles cell membrane Draw and label picture on top of p. 24

Organelles: structures that are specialized to perform distinct processes within a cell. The nucleus is usually the largest and most visible organelle.

Things that have Eukaryotic Cells: PLANTS ANIMALS FUNGI

Cytoplasm: is a jellylike substance that contains dissolved molecular building blocks- such as proteins, nucleic acids, minerals, and ions Bacterium (colored SEM; magnification 8800x)

Draw and label picture on top of p. 24 Prokaryotic cells do not have a nucleus. do not have membrane-bound organelles DNA is in the cytoplasm All are microscopic, single-celled organisms cell membrane cytoplasm Draw and label picture on top of p. 24

Things that have prokaryotic cells Archaea Bacteria

Viruses Virus- An infective agent that typically consists of a DNA or RNA strand in a protein coat. multiply only within the living cells of a host Antibiotics will not work on them Vaccines prevent them Protein Coat EX: Herpes virus Influenza Chickenpox Ebola virus