science 8 unit 4: cells, tissues, organs &...

Science 8 Unit 4: Cells, Tissues, Organs & Systems

How do you know when something is alive?

How do we know when something is alive?

All living things:

• Are made up of cells

• The smallest unit of life, often called the building blocks of life


All living things:


• Grow

• An increase in the number or size of cells


All living things:


• Grow

• Reproduce

• Create more of the same kind (offspring)


All living things:


• Grow

• Reproduce

• Respond to stimuli

• Stimulus- anything that causes an organism to react


All living things:


• Grow

• Reproduce


• Use energy


All living things:


• Grow

• Reproduce


• Use energy

• Move

Cell Theory

• All living things are made up of cells

• Unicellular/ single celled organisms are made up of just 1 cell that carries out all necessary functions

• Multicellular organisms are made up of many specialized cells that carry out specific functions

Flu virus

Cell Theory




• Cells are the basic (smallest) unit of life • There are structures inside cells called organelles

but they can not survive on their own

Cell Theory




• Cells are the basic (smallest) unit of life • There are structures inside cells called organelles

but they can not survive on their own

• All cells come from other pre-existing cells

How are cells organized?

Remember: We said most complex organisms like humans have many types of specialized cells

These cells are organized

in a particular way in the

human body


Tissue: A group of cells of the same type performing the same function ex. Muscle


Tissue: A group of cells of the same type performing the same function ex. Muscle Organ: Different tissues which work together to perform the same function Ex. The heart- contains mostly muscle tissue but also nerve, fat and epithelial tissue


Tissue: A group of cells of the same type performing the same function ex. Muscle Organ: Different tissues which work together to perform the same function Ex. The heart- contains mostly muscle tissue but also nerve, fat and epithelial tissue Organ System: Group of organs that work together Ex. Circulatory system- heart, blood vessels and lungs work together to bring oxygen rich blood to all parts of the body

Cells Tissues Organs Organ Organisms

Systems

Compound Light Microscope

• Magnifies objects using sets of lenses


Eyepiece: • Used for viewing • Contains a lens that magnifies

Arm:

• Supports the eyepiece Revolving Nosepiece:

• Holds the objective lenses

Objective Lenses: • Magnify the image • Most microscopes have 3-4


Fine Focus: •Focuses at high power

Coarse Focus:

•Focuses at low and medium power •Use this knob first

Stage:

•Shelf where the slide is kept

Light Source: •Supplies light used to view the slide


Magnification Power: How much larger a certain lens will make an object appear

Typically:

Low= 4 x

Medium = 10 x

High= 40 x


Magnification Power: How much larger a certain lens will make an object appear

Typically:

Low= 4 x

Medium = 10 x

High= 40 x

Remember: The eyepiece also magnifies the object (usually by 10x)

Total magnification = magnification of lens x magnification of eyepiece


Example:

• low power lens magnifies by 4x

• Eyepiece magnifies by 10x

• Total magnification = 4x10 = 40

Remember: The eyepiece also magnifies the object (usually by 10x)

Total magnification = magnification of lens x magnification of eyepiece

science 8 unit 4: cells, tissues, organs &...

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