Science C1

Question 1

who were the Dutch lens-makers, Hans and Zacharias Janssen?

Answer 1

they invented the microscope in about 1595, using a two-lens system of an eyepiece (ocular lens) and an objective lens. Because it made use of more than one lens, it was called a “compound” microscope. Magnification of this first microscope was about 20x and was significant because it extended the reach of the human eye.

Question 2

Englishman Robert Hooke developed what kind of microscope?

Answer 2

A three-lens microscope. Is credited with using

the term “cell”

Question 3

Anton van Leeuwenhoek, a Dutch businessman,

developed

Answer 3

Lenses that allowed for greater magnification; up to 250x. Under this magnification, he was the first to see the movement of single-celled organisms as small as
bacteria.

Question 4

Diaphragm

Answer 4

Allows for control of how much light passes through the specimen. A disk found under the stage.

Question 5

Base

Answer 5

Provides support for the parts of the microscope, foundation of the microscope, bottom portion of microscope.

Question 6

Ocular lens (or eyepiece)

Answer 6

Type of lens found in the eyepiece, magnifies the image produced by the objective lens (10X).

Question 7

Low power (Red)

Answer 7

Allows for the largest field of view

Question 8

Arm

Answer 8

Can be used for carrying the microscope, holds the lenses the proper distance from the specimen

Question 9

Revolving nosepiece

Answer 9

used to change objective lenses.

Question 10

High power (Blue)

Answer 10

This setting allows for observation of the most detail

Question 11

Magnification

Answer 11

Known as the power of the microscope. Total magnification = (eyepiece)(objective)
Low: (10)(4) = 40x
Medium: (10)(10) = 100x
High: (10)(40) = 400x

Question 12

Magnification can also be calculated by taking a dimension of the image, such as height (hi), and dividing it by the same dimension of the object (ho). (divide diagram size by actual length)

Example: Calculate the magnification power of a microscope if a 1.4 mm long specimen (object = 0) appears to have a length of 46.3 mm (image = i).

(33X)

Answer 12

READ

Question 13

stage clips

Answer 13

Used to hold the slide in place on the stage.

Question 14

Course slip

Answer 14

Placed on top of a specimen that is mounted on a slide

Question 15

Fine focus

Answer 15

Knob on the side of a microscope that allows for small or final adjustments in focus

Question 16

Coarse Focus or Adjustment Knob

Answer 16

Allows for initial or large changes in focus. Moves the stage up/down.

Question 17

Stage

Answer 17

Holds the slide/specimen

Question 18

Objective lenses

Answer 18

Provide various levels of magnification of the specimen

Question 19

Light Source

Answer 19

Provides light necessary to illuminate the specimen

Question 20

Field of view = the entire area that you see when
you look through a microscope
You can use view a rule under the microscope to
measure the diameter of the area that you are
viewing; the field of view, however, the accuracy of
this decreases with increased magnification.
The formula below shows the relationship between
field diameter and magnification:
MHFH = MLFL Where: M = magnification H = high power
F = field of view L = low power

Answer 20

Example: If the low power magnification is 4x, and the
field of view diameter is 4.5 mm, what will be the field of
view diameter for a high power magnification of 40x?

Due to the small size of the field of view, sometimes the
unit micrometer is used. 1 mm = 1000 um.

Question 21

Describe the process of making a wet mount

Answer 21

First, use tweezers to place your specimen on the slide. then, use a dropper to put a small drop of water onto the specimen. lastly, use tweezers to put the coverslip on top of the specimen. if there are bubbles, press down gently on the coverslip a couple of times until the bubbles are gone

Question 22

Cell Theory

Answer 22

1. All living things are made up of one or more cells and the materials produced by these cells.
2. All life functions take place in cells, making them the smallest unit of life.
3. All cells are produced from pre-existing cells through the process of cell division.

(that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells.)x

Question 23

describe the process of bringing a sample into focus on a compound microscope

Answer 23

hh

Question 24

Function of the cell wall

Answer 24

Found in plants; the cell wall is a rigid frame around the cell that provides strength and support.

Question 25

Function of Nucleus

Answer 25

The organelle that contains DNA, genetic material of the cell, and directs all cellular activities (control center); has pores to allow transport of materials.

Question 26

Function of Nucleus

Answer 26

The organelle that contains DNA, directs all cellular activities (control center); has pores to allow transport of materials.

Question 27

Function of Cytoplasm

Answer 27

A gel-like substance inside the cell membrane that contains the nutrients required to carry on the life processes.

Question 28

Function of Ribosomes

Answer 28

Granules (either floating in the cytoplasm or attached to the endoplasmic reticulum) where proteins are produced.

Question 29

Function of Lysosomes

Answer 29

Double membrane sacs within the cell that contain strong digestive enzymes. (Vesicles containing enzymes that break down unwanted things in the cell. Only in animal cell)

Question 30

Function of Endoplasmic Reticulum (ER)

Answer 30

A series of tubes extending from the nuclear envelope;
rough ER contains ribosomes, associated with protein
production and smooth ER, without ribosomes, is associated with lipid(fat) production.

Question 31

Function of Golgi Bodies/Apparatus

Answer 31

Flat disc-shaped sacs involved in packaging substances from the endoplasmic reticulum and transporting them out of the cell. (Bodies which pinch off transport vesicles at the end).

Question 32

Function of Vacuoles and Vesicles

Answer 32

Sites for storage of nutrients, products of secretion, and water. In plants a large central vacuole swells, increasing turgor pressure.

Question 33

Function of Mitochondria

Answer 33

Rod-like structures that are the site of cellular respiration; where chemical energy stored in food is released in a usable form (ATP). (Powerhouse of the cell, creates energy).

Question 34

Function of tubules

Answer 34

responsible for cell transport

Question 35

Organelles

Answer 35

Structure in a cell with a specific function

Question 36

compare and contrast animal and plant cells in terms of their structure and functioning.

Answer 36

Plant cells have a cell wall, but animals cells do not. Plant cells have chloroplasts, but animal cells do not. Chloroplasts enable plants to perform photosynthesis to make food.
Plant cells usually have one or more large vacuole(s), while animal cells have smaller vacuoles, if any are present. Large vacuoles help provide shape and allow the plant to store water and food for future use. The storage function plays a lesser role in animal cells, therefore the vacuoles are smaller. Animal cells are the basic structural and functional units of animal tissues and organs.

Question 37

Resolution

Answer 37

Allows one to better distinguish structures that are very close together through improved clarity.

An increase in the number of pixels (dots or squares of
colour ) can produce better clarity or higher resolution in digital images.

Question 38

Stains are used to

Answer 38

Provide contrast between structures being examined.

Question 39

Which is better: Electron or light microscopes?

Answer 39

Electron microscopes because they have improved resolution that produce images called micrographs.