Transcript Cells - My Teacher Pages

Cells
What do you remember about
cells?
What is an organism made of?
Single-celled organisms are just one cell.
What does unicellular mean?
Examples include the paramecium,
amoeba, and euglena.
What is an organism made of?
Multi-cellular organisms are made of many
cells. What does multi- mean?
Examples include sponges, insects,
worms, fish, amphibians, reptiles, birds,
and mammals.
How do organisms make more
organisms?
A unicellular organism can divide into two
new organisms. The new ones are exactly
like the original.
Multicellular organisms have many ways
to reproduce.
– Some produce exact copies of themselves.
– Others require two individuals who produce
offspring with similar but not exact
characteristics.
Why do the cells in multicellular
organisms divide?
Growth
– Adults have more cells than babies.
– Growing does not make bigger cells.
Repair
– Damage to cells on the inside or outside makes cells
die.
– They must be replaced by new cells.
Reproduction
– Egg and sperm cells must have half the genetic
information (DNA) of the original cell.
– When an egg and sperm join, the new organism will
have the correct amount of DNA.
How are cells organized to form
an organism?
Similar cells are grouped as tissues.
In animals, muscle cells → muscle tissue
In plants, leaf cells → leaf tissue
Tissues are grouped into organs.
In animals, some muscle tissue is grouped into
muscles and other muscle tissue is grouped to
form a heart.
In plants, several kinds of leaf tissue forms a leaf.
Several organs form a system.
Several systems form the organism.
What do cells do for the
organism?
All cells must
change food molecules into energy to do
their work,
get rid of waste products, and
divide to make new cells.
How is this like what organisms must
do?
What do cells do for the
organism?
Plant and animal cells are specialized to do
specific jobs such as
Making proteins or other molecules
Changing simple molecules into glucose during
photosynthesis
Storing energy
Taking in or releasing water
Sensing the surroundings
How is this like what organisms do?
How are the structures or
shapes of cells related to their
functions?
Plant cells have cell walls that support the
cells.
Leaf cells have chloroplasts to capture light
energy for photosynthesis.
Nerve cells in animals are long and thin. They
carry chemical and electrical messages to
the brain.
Muscle cells in animals relax and contract.
What other examples can you think of?