Transcript Unicellular and Multicellular Organisms

Unicellular and Multicellular
Organisms
Unicellular Organisms
• Most are microscopic
• Examples: Amoeba, Paramecia, E. Coli
• Perform the same tasks as multicellular
organisms
• They move, eat, reproduce and expel waste.
THE AMOEBA
Binary Fission (cell
division)
PARAMECIA
The Amoeba
• Have characteristics of an animal cell
• Live in fresh and salt water environments
and decaying vegetation sites.
• Are predators – they prey on algae and
bacteria
• Uses osmosis to get water and diffusion to
get oxygen and dispose of carbon dioxide.
Multicellular Organisms
• Rely on a variety of cells to perform cellular
functions. These are called “specialized cells”.
• Specialized cells perform duties such as digestion
or movement.
• Example: Eyes, Muscles and Tongue. (what
duties do these perform?)
• Cells can be compared to small cities. Each one
performs a different job/function. They all work
together to be efficient. Just like we need
specialist doctors, cells need specialist cells.
Question to Consider
• Why do you think small cells are more
efficient than large cells?
Cellular Process in Plants and
Animals
• Materials enter cells through diffusion and
osmosis
• Cells break down materials and convert them to
energy, to transport energy from one place to
another, to build protein and send chemical
messages.
• Cells also expel waste products. The higher
number of cells, the more waste that is expelled.
Energy
• Energy is necessary for digestion, transport,
reproduction and repairing damage to cells
• In animal cells, the mitochondria are responsible
for breaking down carbs and releasing energy.
• Specialized cells like liver and muscle cells have
more mitochondria than other cells in the animal
system. Why do you think this is?
• In plant cells, chlorophyll convert energy to sugars
using water, carbon dioxide and nutrients.
Processing and Transporting
Main Cell Parts: Cytoplasm, Endoplasmic
Reticulum, Golgi Apparatus, Lysosomes
• Materials move through the cytoplasm
• The Endoplasmic Reticulum creates protein from
the materials and passes them to the Golgi
Apparatus
• The Golgi apparatus processes the protein and
secretes them outside the cell to be used in other
places.
• Lysosomes break down food and digest waste.
Reproduction
• Cells have a life span. Amoeba live for
approximately 2 days.
• Brain cells: 30-50yrs
• Red Blood Cells: 120 days
• Skin Cells – 20 days
• New cells are created through cell division, when
one cell splits into two. First the nucleus splits,
and then the remainder of the cell.
• The two new cells are identical.
• In plant cells, the nucleus divides and then a new
cell wall is created.
CELL DIVISION
Do you Get It?
• Consider the following question:
A unicellular organism is a living thing that meets
all of the basic needs with just one cell. A
multicellular organism can require up to several
trillion cells to do the same thing. Which do you
consider to be more advanced? Explain your
reasoning.