Lab Exam 1

Question 1

Hardy-Weinberg Principle

Answer 1

A population’s allele and genotype frequencies are constant, UNLESS there is some type of force acting upon them.

Question 2

For equilibrium to exist, five conditions must be met:

Answer 2

1. No natural selection
2. No mutation
3. No migration
4. Large population
5. Random mating

Question 3

Genetic Drift

Answer 3

Changes in allelic frequencies of a gene that are due solely to chance

Question 4

Bottleneck Effect

Answer 4

An extreme example of genetic drift that happens when the size of a population is severely reduced

Question 5

The Founder Effect

Answer 5

The reduction of genomic variability that occurs when a small group of individuals become separated from a larger population

Question 6

Natural Selection

Answer 6

The process by which members of a population become adapted to their environment

Question 7

Ocular (eyepiece)

Answer 7

Magnifies the image produced by the microscope’s objective

Question 8

Draw Tube

Answer 8

Connects the ocular to the body tube

Question 9

Body

Answer 9

Hold the nosepiece at on end and includes the draw tube

Question 10

Arm

Answer 10

Serves as a handle

Question 11

Nosepiece

Answer 11

Holds the objective lenses & attaches them to the microscope head

Question 12

Objectives

Answer 12

Directly observe the object under the microscope that the user is examining

Question 13

Scanning Objective

Answer 13

4x
Used for viewing larger specimens or searching for a specimen; the shortest objective; magnifies the object 4x

Question 14

Low-Power Objective

Answer 14

Used for coarse and preliminary focusing; magnifies the object 10x

Question 15

High-Power Objective

Answer 15

Used for final and fine focusing; magnifies the object 40x

Question 16

Oil-Immersion Objective

Answer 16

Uses the optical properties of oil immersion to magnify a specimen; magnifies the object 100x

Question 17

Stage

Answer 17

platform on which slides are placed
To control the movement of slides, stage clips secure the slides

Question 18

Light Source (Illuminator)

Answer 18

Serves as the source of illumination for the microscope

Question 19

Iris Diaphragm

Answer 19

Regulates light entering the micropscope; usually is controlled by mechanical lever or rotating disk

Question 20

Condenser

Answer 20

A lens system found beneath the stage; used to focus the light on the specimen

Question 21

Coarse-focus adjustment knob

Answer 21

Used to adjust the microscope on scanning and low-power ONLY

Question 22

Fine-Focus Adjustment Knob

Answer 22

Used to adjust the specimen into final focus

Question 23

Base

Answer 23

The supportive portion of the microscope, which rests on the laboratory table

Question 24

Total Magnification

Answer 24

A multiplication of the power of the objective and ocular (eyepiece)
E.g. Scanning objective is 4x and eyepiece is 10x; total magnification = 40x

Question 25

Resolving Power

Answer 25

The ability to resolve objects (distinguish between two closely saved, minute objects and separate entities)

Question 26

Stereomicroscope

Answer 26

Also known as dissecting microscope. Has two oculars and capable of 4x to 50x magnification
Provide a greater field of view and depth to field than compound microscopes so more advantageous when viewing larger objects and dissecting

Question 27

Working Distance

Answer 27

The distance between the objective lends and the specimen.
As the working distance decreases, the magnification increases.
More light is needed when the working distance decreases

Question 28

Field of View

Answer 28

the circular field you see when you through the ocular.
the size of a specimen can be estimated if one knows the field of view at each magnification

Question 29

Depth of Field

Answer 29

The thickness of the specimen in focus at any one time