CELLS TO BODY SYSTEMS
UNIT REVIEW
By Mrs. Susan Dennison
2012-13
What are cells?
Cells are the basic units of structure and
function of all living things. They are also
called the “building blocks” of life.
What is an organism?
An organism is a living thing made up of one
or more cells, each able to support the
functions (jobs) of life.
We should add
here that another
must-have characteristic
is to be made up of 1 or
more cells!
How many cells make up certain
types of organisms?
The simplest organisms, such as bacteria or
an amoeba, are each a single cell. However,
most plants and animals are made of many
cells. Humans, for example, are made up of
trillions of cells! Each cell has a particular
function (job).
What determines the
size and shape of a cell?
The size and shape of a cell depend on its
function. For example, red blood cells are
small and disc-shaped so they can fit through
blood vessels. Muscle cells are long and thin
because they need to contract and stretch.
Who “discovered” cells?
Several scientists made important
observations and conclusion about cells.
Robert Hooke recorded his
observations of cork cells in
1665. He coined the term “cell”
while working in England.
Matthias Schleiden, a German
botanist, concluded that all
plants are made of cells.
Theodore Schwann, a German
zoologist, concluded that all
animals are made of cells.
How do scientists view cells?
Scientists view microbes and cells with a
microscope. Dutch scientist, Anton Van
Leeuwenhoek, is considered the “Father of
Microbiology” because the important advances
he made to the design of microscopes.
What are the parts of a cell?
Each cell has even smaller structures inside,
called organelles. Each organelle has a particular
job, or function, in the life processes of a cell.
Are plant and animal cells different?
Yes! Two organelles (smaller structures inside
cells) that only plant cells have are cells walls
and chloroplasts.
Which organelles do I need to know
about this year, in 5th grade?
Plant Cells
1. Nucleus
2. Chromosomes
3. Cell Wall
4. Cell Membrane
5. Cytoplasm
6. Chloroplasts
7. Vacuole
8. Mitochondria
Animal Cells
1. Nucleus
2. Chromosomes
3. Cell Membrane
4. Cytoplasm
5. Vacuoles
6. mitochondria
What is the nucleus?
The nucleus is the organelle that controls all
of a plant or animal cell’s activities and the
production of new cells.
Here, you can see
The nucleus in human
cheek cells, just like you
did in your 2nd class
lab!
What are chromosomes?
Chromosomes are threadlike structures that
contain information about the characteristics
of the plant or animal, like eye color, flower
color, shape, etc.
What is a cell membrane?
The cell membrane is a covering that holds the
plant or animal cell together and separates it
from its surroundings.
When you think about a membrane, imagine it
is like a big plastic bag with some tiny holes.
That bag holds all of the cell pieces and fluids
inside the cell and keeps other things outside
the cell. The holes are there to let some things
move in and out of the cell in a process called
osmosis.
What is a cell wall?
Only plant cells have cell walls! They are rigid
layers that support and protects plant cells.
What is cytoplasm ?
Cytoplasm is a jellylike substance that contains
many chemicals to keep the cell functioning.
What are chloroplasts?
Chloroplasts are organelles that help make
food for the plant cell during photosynthesis.
Only plant cells need them, so only plant cells
have them!
What are vacuoles?
Vacuoles in plant and animal cells are
organelles that store food, water, and waste.
What are mitochondria?
Mitochondria are organelles in plant and
animal cells that release energy from food.
How do materials move
in and out of a cell?
Cells need to get needed materials like food,
water, and oxygen. They also need to get rid of
wastes, like carbon dioxide. Materials move in
and out of cells by a process called diffusion.
What is osmosis?
Osmosis is the movement of water and
dissolved materials in and out of a cell
through a cell membrane.
Normal onion cells plumped
Up with water and cytoplasm
Inside the cell membrane
Onion cells that have
less water in them-the cytoplasm
has started to shrink.
Can I see osmosis?
In a way, you see it all of the time! Not at a
cellular level, though. By drinking, animals
replace the water their cells lose. By soaking up
rain in the soil, water moves back into the
plant’s cells.
How are our bodies organized?
Cells work together to make tissues. Tissues
work together to form organs. Organs work
together to form organ systems.
What are examples of cells?
Plants and animals have many types of cells,
including: skin cells, muscle cells, blood cells,
stem cells, etc.
What are examples of tissues?
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•
•
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Muscle tissue- made up of cells that contract
and relax to move your skeleton
Nervous tissue- made up of cells that get
signals from the brain to hear, see, taste, touch,
and smell
Connective tissue- made up of cells that are in
bones, cartilage, and tendons
Epithelial tissue- made up of cells that cover
the body of an animal and make the lining of
most internal organs
What are examples of organs?
Organs are layers of tissue. Each organ in an
animal’s body performs a certain function
that keeps the animal alive. Examples include
the: heart, lungs, kidneys, gallbladders, etc.
STUDY YOUR SCIENCE NOTES!
There will be more information tested. You
have a variety of notes, diagrams, and
information in your science notebooks to use
for this content. Hopefully, you’ve been
studying all along and don’t have to cram!