BIOLOGY NOTES AND MICROSCOPES

BIOLOGY IS….

…the study of life, So what do we study? What defines a living thing?

Six Characteristics: Cells Organization Energy Use Homeostasis Growth Reproduction

SIX CHARACTERISTICS OF LIFE

Cells All living things have cells

Some have a nucleus, some don’t

ORGANIZATION

all living things are organized

ENERGY USE

All living things require energy to do everything else Repair cells Move Grow

HOMEOSTASIS

Maintain stable internal conditions

GROWTH

Get bigger by making more cells Develop

REPRODUCTION

Produce offspring similar to self Sometimes can mix genetic information

IS A DOG ALIVE?

Cells – Dogs have red blood cells Organization – Dogs have bones to help it

stand Energy Use – Dogs use energy to run and

chase squirrels Growth – Dogs grow by multiplying their cells

and can heal when they get hurt Homeostasis – When a dog is hot, it moves

into the shade Reproduction – Dogs mate and give birth to

puppies YES DOGS ARE ALIVE!

IS A CALCULATOR ALIVE?

Cells – Does have solar cells but does not have regular cells with DNA and a membrane

Organization – Is organized with each button having a job

Energy Use – needs batteries or light to work Growth – Calculators do not get larger over

time nor do they change in anyway Homeostasis – If the temperature is freezing,

the calculator is freezing too Reproduction – calculators do not have baby

calculators. NO CALCULATORS ARE NON-LIVING

MICROSCOPES

Tool for observing small specimens Magnification – how much bigger an

object looks Resolution – how clear the picture is Robert Hooke: using a simple microscope observed the first plant cells in cork, 1665 Anton van Leeuwenhoek observed the

first living cells, 1673. He made some of the first microscopes.

LIGHT MICROSCOPE

Ocular Lens – eye piece, 10x Body Tube Revolving Nosepiece – hold objective lenses Objective lens – near object,

4x = scanning 10x = low 45x or 100x = high

Stage and Stage clip – holds slide Diaphragm or Condenser – focuses light Light Coarse Focus – moves quickly Fine Focus – perfects image

MAGNIFICATION

Total magnification is: ocular lens x the objective

10x X 4x = 40 times magnified

The object should look 40x larger than normal

Field of view – the size of the area you can see

Which picture has a larger field of view?

ELECTRON MICROSCOPE

Uses a beam of electrons Transmission TEM Scanning SEM