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 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