The Cell Theory Unit 3 – Lesson 2 Notes

Vocabulary Cells The basic units of structure and function of living things. Organelles The structures that make up a cell. Literally means “many organs”. Humans have organs. Cells have organelles! Cells are a tiny life form.

History of Cells Before microscopes, people didn’t know about microscopic life. Their views were extremely misinformed. An example: people thought insects were born from meat! HOW DID WE LEARN THAT CELLS EXIST?  We have old dead scientists to thank!

Scientists – Robert Hooke Looked at cork cells. Cells were dead. The cells looked like “empty rooms”. Hooke was the first scientist to give “cells” their name.

Scientists – Anton van Leeuwenhoek Examined blood, rainwater, and scrapings from his teeth. He observed living cells. He called them “Animalcules”. The smallest of these are known today as bacteria.

Scientists – Matthias Schleiden Viewed plant parts.

Scientists – Theodor Schwann Viewed animal parts.

Scientists – Rudolph Virchow Discovered that all living things come only from other living things.

The Cell Theory 1. All living things are made of cells.

The Cell Theory 2. Cells are the basic units of structure and function in living things. CELL TISSUE ORGAN ORGAN SYSTEM ORGANISM

The Cell Theory 3. All living cells come from other living cells.

What Does it Mean to Be Living? All living things : have DNA can grow and develop reproduce respond to stimuli keep homeostasis (a balance) obtain and use energy

Cells All living things can be classified into 6 categories: Archaebacteria Bacteria Protists Fungi Plants Animals

Cells 3 of these kingdoms live life as a single cell! We say they are unicellular! Archaebacteria Bacteria Protists archaebacteria bacteria protists

Cells 3 of these kingdoms live life as a cluster of cells. We say they are multicellular! Fungi Plant Animal fungi animal plant

Multicellular or Unicellular?

Multicellular Organisms Multicellular organisms are ORGANIZED. The cells don’t just float around at random, They work together to make different structures. cells make tissue…

CELL TISSUE ORGAN ORGAN SYSTEM ORGANISM

Comparing Cells There are many different types of cells, we categorize them into two types. Prokaryotes Eukaryotes

Prokaryotes Prokaryotes – lack membrane bound organelles. Examples: Archaebacteria Bacteria Uhh, what’s a membrane?

BACTERIA

Eukaryotes Eukaryotes – cells that contain membrane bound organelles. Examples: Protists Fungi Plants Animals

Protists Amoeba – single cell organism - moves with a pseudopod (foot like projection)  Paramecium – single cell organism - has cilia – short hair-like projections

Fungi There are four types of fungi: sac fungi zygote fungi club fungi imperfect fungi Sac FungiImperfect Fungi Zygote Fungi Club Fungi

Eukaryotes We will be discussing animal cells and plant cells in later units. Animal CellPlant Cell

ANIMAL CELL

Different Cells Do Different Jobs Red Blood Cell Nerve Cell

PLANT CELL

Different Cells Do Different Jobs Guard Cell Cells in Leaf

ProkaryoteEukaryoteUnicellularMulticellular Archaebacteria Bacteria Protist Fungi Plant Animal