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
How do we know when something is alive?
All living things:
• Are made up of cells
• Grow
• An increase in the number or size of cells
How do we know when something is alive?
All living things:
• Are made up of cells
• Grow
• Reproduce
• Create more of the same kind (offspring)
How do we know when something is alive?
All living things:
• Are made up of cells
• Grow
• Reproduce
• Respond to stimuli
• Stimulus- anything that causes an organism to react
How do we know when something is alive?
All living things:
• Are made up of cells
• Grow
• Reproduce
• Respond to stimuli
• Use energy
How do we know when something is alive?
All living things:
• Are made up of cells
• Grow
• Reproduce
• Respond to stimuli
• 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
• 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
• 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
• 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
• 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
How are cells organized?
Tissue: A group of cells of the same type performing the same function ex. Muscle
How are cells organized?
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
How are cells organized?
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
Compound Light Microscope
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
Compound Light Microscope
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
Compound Light Microscope
Magnification Power: How much larger a certain lens will make an object appear
Typically:
Low= 4 x
Medium = 10 x
High= 40 x
Compound Light Microscope
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
Compound Light Microscope
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
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