Organization of Living Systems
Living things are . . .
• Organized into cells
• Grow and develop
• Respond to the
environment
• Use energy
• Reproduce
 Lack a nucleus
Example: Bacteria
 Contains a nucleus
and other organelles.
Example: Animal & plant cell
Prokaryote vs. Eukaryote
Eukaryotic Cells
Cell Part
Function
Cell membrane
Controls what enters and leaves the cell
Nuclear membrane
Controls what enters and leaves the nucleus
Nucleus
Control center of the cell
Chromosomes
Genetic information in the nucleus
Endoplasmic Reticulum
Transport system in cell
Ribosome
Organelle that makes proteins
Golgi Body
Organelle that packages proteins
Vacuole
Stores water and/or waste
Lysosome
Enzymes that digest or break down worn out
cell parts, excess food, and invading bacteria
or viruses
Mitochondria
Organelle for cellular respiration – provides
energy
Plant vs. Animal Cell
Plant Cells Have,
and Animal Cells Don’t• Chloroplasts – organelle
responsible for
photosynthesis.
• Cell Walls – a structure
outside of the membrane
to provide support.
• Very large vacuoles to
store extra water.
This is a typical plant cell• It contains a cell wall,
chloroplasts, a very large
vacuole.
• Why do plants need
large vacuoles?
•ANSWER: This is
where food and water
are stored.
Q: Which structure found in plant
cells is responsible for
photosynthesis?
(A) Cell membrane
(B) Chloroplast That would be B, the
chloroplast!!!
(C) Ribosome
(D) Nucleus
Animal Cell
Q: The swordfish has a heat-generating
organ that warms it brains and eyes up to
14°C above the surrounding water
temperature. What structures are likely to
be found in relatively high concentrations
in the cells of this organ.
(A) Chromosomes
(B) Mitochondria
(C) Nuclei
(D) Ribosomes
A. No, chromosomes contain genetic information.
B. Mitochondria, because they produce the energy
needed to generate the heat.
C. No, the nucleus is the control center of the cell and
where the chromosomes are housed.
D. No, ribosomes are the site of protein synthesis.
Q: You are looking at a cell under a
microscope. You observe that the cell has a
cell membrane and cell wall but does not have
a nucleus or any membrane-bound organelles.
Based on this observation you can conclude
the cell is –
(A) A plant cell
(B) A bacterium
(C) An animal cell
(D) Dead
B, a bacteria.
Both plant and animal cells
contain a nucleus.
Homeostasis
• This is the maintenance of the normal operating
conditions of an organism.
• Control of body temperature, pulse rate, blood
pressure, blood sugar, urine output, digestive
absorption, metabolism rate, growth rate and
hormone levels all need to be maintained.
Transporting into Cells Diffusion
Osmosis is
the diffusion
of H2O
• Passive movement of molecules from an area of high
concentration to an area of low concentration is
diffusion.
• The diffusion of water across a cell membrane is called
osmosis.
What is Active Transport?
Energy is used to move selected molecules into a cell,
even if they are at a low concentration.
Q: When a sea urchin egg is removed from the
ocean and placed in freshwater, the egg swells
and bursts. Which of these causes water to
enter the egg?
Means to clump together – Incorrect
(A) Coagulation
Sodium is not being moved –
(B) Sodium pump
Incorrect
(C) Active transport
The egg would not use energy to do
(D) Osmosis
this since it kills the cell.
This is the movement of water from an area of high
concentration (the fresh water) to low concentration
(inside the Salt Water Urchin Egg)
Q: What happens to a cell when
particles move out of the cell through
facilitated diffusion?
(A) The cell gains energy.
(B) The cell uses energy. B is the answer!!!
(C) No energy change takes place.
(D) The cell produces energy.
6CO2 + 6H2O  C6H12O6 + 6O2
Carbon Dioxide Plus Water Produces Glucose And Oxygen
THIS IS
PHOTSYNTHESIS
Plants do Photosynthesis and Cellular Respiration
Cellular Respiration
• C6H12O6 + 6O2  6CO2 + 6H2O
• Occurs in mitochondria of all living
things.
Q: The diagram shows the flow of
energy converted during
photosynthesis. From this diagram it
can be inferred that –
A) atmospheric gases are the source of
energy for producers
B) organisms depend on organic
compounds to transfer energy
C) ultraviolet radiation from the sun is
used for photosynthesis
D) heat from plants and animals warms
atmospheric gases
Q: What is the name of the ability of
organisms and cells to maintain a stable
internal environment called?
(A) Homeostasis
(B) Endoplasmic reticulum
(C) Photosynthesis
(D) Chloroplast
You are too smart,
HOMEOSTASIS is
correct!!!