Unit 2:What is a Cell?

Cells are: different shapes and sizes

Cell Theory1. All Living things are made of one or

more cells.

2. All cells come from pre-existing cells– Cell reproduce

• Asexual reproduction

• Sexual reproduction

3. All cells carry out life’s activities – Exchanging O2 and CO2, – Producing proteins– replacing dying/dead cells

Scientists and Cell Theory

• Pasteur -• Redi -• Hooke -• Brown -• Schwann- • Schlieden-• Virchow-• Van Leewuenhoek-

In your Groups!

All cells are characterized as either:

• A prokaryote (prokaryotic)Or

• A Eukaryote (Eukaryotic)

KNOW THESE TERMS!!

A Prokaryotic Cell:• Have genetic material that

is NOT contained in a nucleus

• Genetic material is “floating” in the cytoplasm

• Usually smaller than eukaryotic cells

• Considered the earliest cells

• No membrane bound organelles: nucleus, chloroplast, or mitochondria

A eukaryotic cell:• Genetic material is

contained within the NUCLEUS

• Genetic material is separated form the rest of the cell

• Can be unicellular or Multicellular

Cells can be:• Unicellular – only 1 cell large

• Ex’s bacteria, ameba’s, paramecia

Cells can be

• Multicellular – made of many cells• Can be simple organisms • or complex• Ex. Hydras and humans

Parts of Cells

• Cells contain many internal structures called organelles

• Each organelle performs a specific function vital to life

• Letters A-Q represent cell organelles

Cell Organelles:

• Microscopic structures that make up the cell

• Each organelle performs a specific function for the cell

• Ex of organelles:

– nucleus

– Mitochondria

– Chloroplasts

– Golgi bodies

Differences b/w plant and animal Cell

1. Vacuole:• Plants have 1 large vacuole• Animal cells have multiple smaller vaculores2. Chloroplasts are plants only!!!

(photosynthesis)3. Cell Wall found in plant cells only!!4. Centrioles found in animal cells only!!!5. Shape: boxy shapes = plant

rounded = animal

Plants vs. Animal Cells:

• Plant Animal

1. Boxy shape roundish shape

2. Chloroplasts none

3. None Centrioles

4. Cell wall none

5. 1 large Vacuole many small vacuoles