Biology quiz march 14

Anton van Leeuwenhoek

Developed the first microscope

Observed pond water and discovered the microscopic life that lives within

Robert Hooke

First person to use the term “cells” by observing plant cell walls in cork

Mitosis

Regular cell division

Most cells replicate by

making exact copies of themselves

Robert Brown

Discovered that many cells have a dark spot near the center

Credited with discovering the nucleus

Matthias Schledien

Stated that “all plants are made of cells”

Theodor Schwann

Stated that “all animals are made of cells”

Rudolf Virchow

stated that “all cells arise from the division of preexisting cells”

Transmission Electron Microscope magnification

capable of over 1,000,000x magnification

What must be done to specimens to be placed in the Transmission Electron Microscope?

Frozen or embedded in plastic and sliced thin

How do Transmission Electron Microscopes work?

Use magnets to focus a beam of electrons on the specimen.

Scanning electron microscope magnification

100,000x

Scanning electron microscope is capable of

producing a 3-D, photograph-type image

How does the scanning electron microscope work?

beam of electrons sweeps across the object and bounces back to be interpreted by a computer

Neither the TEM or the SEM use

Lenses

A magnifying glass is a

Simple light microscope

The word “light’ in a light microscope means…

you actually see the light reflecting off the surface of the specimen

In a compound light microscope, the word compound means…

it has two lenses (objective and ocular/eyepiece)

To calculate the total magnification in the compound light microscope, you…

multiply the objective lens magnification times the eyepiece magnification

Scanning objective lens

Red, 4x

Low power objective lens

Yellow, 10x

High Power objective lens

Blue, 40x

What is #1

Ocular

What is #2

Eye piece

What is #3

Revolving nosepiece

What is #4

Objective lenses

What is #5

Diaphragm

What is #6

Stage

What is #7

Light source

What is #8

Base

What is #9

Coarse adjustment

What is #10

Fine adjustment

What is #11

Arm

What is #12

Stage clips

Resolution

ability to distinguish between two objects

What does the diaphragm do?

Adjusts the level of light

What does the stage do?

Specimen is placed on the stage

What does the revolving nosepiece do?

Allows objective lenses to be rotated

What do the coarse and fine adjustments do?

Raise and lower the stage

When you pick up a microscope, you should have…

one hand supports the arm, one hand supports the base

Cell theory #1

All living things are made up of one or more cell.

Cell theory #2

The cell is the basic unit of organization of living things.

Cell theory #3

All cells come from pre-existing cells.