Transcript Cells: Basic Unit of Life

Cheek Cells
Moss Cells
Cells: Basic Unit of Life
Part 1
Onion Cells
Blood Cell
MS-LS1-1: Conduct an investigation to provide
evidence that living things are made of cells: either one
cell or many different numbers and types of cells.
I. Discovery of Cells
•
First Sighting of Cells
in late 1600’s
a. Robert Hooke (1665)i. built one of the first
compound microscopes
ii. Discovered cork
cells
b. Anton van Leeuwenhoek
(1673)i. discovered creatures
swimming in pond scum
ii. First person to see
bacteria and
discovered that
yeast makes bread
rise
Cork Cells
Discovery of Cells (cont.)
c. Matthias Schleideni.stated all plants are
made of cells (1838)
d. Theodor Schwanni. stated all animals are
made of cells (1839)
e. Rudolf Virchowi. saw cells could not
develop from anything
but cells (1858)
–
Both scientists
contributed to cell
theory
Cell Theory
f. Cell Theory:
1. All organisms are
composed of one or
more cells.
2. The cell is the
basic unit of life in
all living things.
3. All cells come from
existing cells.
Question
Explain the cell theory:
a. ____________________________
b. ____________________________
c. ____________________________
Question
Explain the cell theory:
a. all organisms are made of one or more
cells.
b. the cell is the basic unit of life.
c. all cells come from other cells.
g. Microscopes
a.
Compound Microscopei. uses light to pass
through specimen
ii. Lenses magnify the
image making it appear
larger
Microscopes (cont.)
Mite
b. Electron
Microscopes
i. Beam of electrons are
used to magnify
images instead of light
ii. Living specimens can
not be examined
iii. Higher resolution
(clearer image)
iv. Ex. Transmission
Electron Microscope
(flat image) and
Scanning Electron
Microscope (3D
Image)
Electron Scanning Microscope
Ant
Transmission Microscope
Questions
1. Which microscope uses light passing
through the image? ________________
2. What do scientists use microscopes for?
___________________________________
3. How did the discovery of the microscope
help scientists learn more about cells?
___________________________________
Questions
1. Which microscope uses light passing through
the image? Compound light microscope
2. What do scientists use microscopes for?
Observe organisms that are smaller than unaided
eye.
3. How did the discovery of the microscope help
scientists learn more about cells?
Helped to see inside the cell and to discover things
like bacteria.
II. Living or Non Living:
a. 6 characteristics of living things:
• Made of cells
• Have DNA
• Respond to stimulus: homeostasis –
process of maintaining a stable internal
environment
• Use Energy: metabolism- the total of all
of the chemical activities that an
organism performs.
• Grow & Develop
• Reproduce
b. Basic Needs of Living Things
•
•
•
•
Place to Live
Air [oxygen or carbon dioxide]
Water
Food
– Autotroph/ Producers: makes own food
(plant, protist)
– Heterotroph/ Consumers: get food from
other sources (animal, fungi, protist)
III. Two Types of Cell
a.Prokaryote-
i. No nucleus
ii. No membrane
covered organelles
iii. Circular DNA found
in cytoplasm
iv. Smallest cell
v. Ex. Bacteria
b. Eukaryotei. Nucleus
ii. Membrane-covered
organelles
iii. Linear DNA found in
nucleus (chromatin)
iv. 10 times larger than
bacteria cells
v. Ex. Plants, animals,
fungi, and protists
Questions
1. Is a dolphin living or non-living? Explain
_______________________________________________
_______________________________________________
2. What do organisms need to survive?
_______________________________________________
_______________________________________________
3. What are the two types of cells?
– ___________________________
– ___________________________
4. Which type of cell has a nucleus? ______________
5. Give an example of a eukaryote: _______________
Questions
1. Is a dolphin living or non-living? Explain A dolphin is
considered living because meet all 6 characteristics ot
living things
2. What do organisms need to survive? Organisms need air
(oxygen for animals and carbon dioxide for plants), living
space, water and food
3. What are the two types of cells?
– Prokaryote
– Eukaryote
4. Which type of cell has a nucleus? Eukaryote
5. Give an example of a eukaryote: dolphin
IV. Organisms Independent Living
Living things are made of cells a single cell or
many different cells working together.
a.Unicellular:
•one celled organism living on its own
•Can survive on its own
•Example- amoeba, bacteria, paramecium
b. Multicellular:
•many cells that work together.
•Multicellular organisms can grow larger and have
cells that are specialized for different tasks.
Must remain part of the organism to survive.
•Example: flower, dog, human, insect,mushroom
Questions
1. How do the cells of unicellular organisms differ
from the cells of multicellular organisms?
______________________________________
______________________________________
2. Explain the advantage of being multicellular.
______________________________________
______________________________________
Questions
1. How do unicellular organisms differ from the
multicellular organisms?
Unicellular organisms are one cell which must do
all the jobs for the cell, they can survive on their
own. Multicellular are many celled, and must
remain part of the organism to survive.
2. Explain the advantage of being multicellular.
______________________________________
______________________________________