Download Chapter 1 Lesson 1

5th Grade-Chapter 1 Lesson 1- Cells
VOCABULARY
1. organism2. cell3. unicellular4. multicellular5. chlorophyll6. tissue7. organ8. organ system-
NOTES
What are cells?

Cells are the smallest unit of living things that can carry out the basic processes of
life.
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Cells come from other cells.

A cell divides, or splits, into two new cells.

Unicellular-one-celled organism
o Life processes include growing, responding to an environment,
reproducing, and getting food.
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Multicellular-many-celled organism.
o Ex: trees, frogs, and humans
o Every cell carries out its own life process.
o Cells work together to take care of different functions.

Scientists estimate that there are more than 1 billion kinds of unicellular
organisms.
What is inside an animal cell?

Your body has more than 200 different kinds of cells.

Plant and animal cells have several basic structures called organelles.

Organelles help cells perform life processes. They have functions that help keep
cells alive.

Cell Membrane
o The layer around the outside of the cell.
o Gives cell its shape.
o Controls what materials move into and out of the cell.

Cytoplasm
o Gel-like liquid
o Occupies the region from the nucleus to the cell membrane.
o Made mostly of water.
o Organelles float in the cytoplasm.
o Supports cell structures.
o Constantly moving through the cell in a stream-like motion.

Nucleus
o Cell’s control center.
o Large, round organelle usually found in the center of the cell.
o It has a membrane with pores, or openings, that allow certain materials to
pass in and out.
o Contains the master plans for all the cell’s activities.
o Sends signals to other parts of the cell.
o Controls the growth, movement, and division of cells.

Mitochondria
o Oval, membrane-covered organelles that supply energy for the cell.
o Tiny power plant.
o Break down food, which releases energy for cell use.
o Cells that require a lot of energy usually have a great many mitochondria.

Vacuoles
o Membrane-covered structure used for storage.
o Stores water, food, and wastes.
o Can signal a vacuole to release whatever it is storing.
o Some animal cells have many small vacuoles and some may not have any
vacuoles.
What is inside a plant cell?

Plant cells have many of the same structures and organelles as animal cells.

Plant cells often have a box-like shape and are a bit larger than animal cells.

They have some additional organelles that animal cells do not have.
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Cell Wall
o Additional outer covering around the outside of the cell.
o Stiff structure outside the cell membrane.
o Provides plant cell with strength and extra support.

Vacuole
o Plants cells have one large, central vacuole.
o Stores excess water and provides extra support.
o Extra water keeps the plant from drying out.

Chloroplast
o Where plants make their own food.
o Green structure where the energy from sunlight is used to produce food fro
the plant.
o Green because they contain chlorophyll.
o Plant cells that lack chloroplast are not green.
o Found in the cells of leaves and stems of plants.
How are cells organized?

Unicellular- simple organization.
o One cell that performs all life functions.

Multicellular-specialized organization.
o Different cells performing different functions.
o Ex: muscles cells specialize in movement, red blood cells carry oxygen

Cells working together form tissues.
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Tissues working together form organs.
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Organs working together form organ systems.
o Ex: circulatory system, digestive system, nervous system.

All of the cells, tissues, organs, and organ systems form an organism.