BioLab Week 1-7

Question 1

Determine the independent and dependent variable in the situation:
- Plant growth is affected near a factory due to SO2

Answer 1

Independent (manipulated): levels of SO2
Dependent (variable that is measured/counted): Plant height
Controlled variable???? Sunlight?

Question 2

What kind of variable is controlled, measured, counted, in response to experimental conditions?

Answer 2

Dependent variable

Question 3

What kind of variable is manipulated in an experiement?

Answer 3

Independent variable

Question 4

What kind of variable is constant in an experiment and can have significant effect?

Answer 4

Controlled variable

Question 5

What is another name for controlled variable?

Answer 5

Alternative independent variable
think because a control variable is constant, it is the alternate/opposite of independent

Question 6

What are the six scientific process steps?

Answer 6

1) Observation
2) Question
3) Hypothesis
4) Prediction
5) Test
6) Results

Question 7

What were three observations of the monarch butterfly experiment?

Answer 7

1) High level of infection/ parasites reduce butterfly fitness
2) Reproduction of parasite was reduced Asclepias CURassavica compared to Asclepias incarnata
3)Asclepias curassavica has higher concentrations of cardenolides (plant toxin) than asclepias incarnata

Question 8

What was the hypothesis for the monarch butterfly experiment?

Answer 8

Infected butterflies laid more eggs (oviposit) on plants that reduce parasitic growth (asclepias curassavica)

Question 9

How was the monarch butterfly experiment designed and performed?

Answer 9

a) Parasite infected and uninfected female butterflies were put in mating cages
b) Butterflies lay eggs in separate cages containing two milkweed plants with diff levels of anti-parasite chemicals (ACur. has higher level than AIncarn.)
c) The number of eggs that were laid were counted
d) The experiment was repeated two days later

Question 10

What was the dependent (counted/measured variable) of the butterfly experiment?

Answer 10

The amount of eggs on the two plants

Question 11

What was the independent (manipulated) variable of the butterfly experiment?

Answer 11

The presence of parasites / infected butterflies

Question 12

What was the controlled (alternate independent) variable in the butterfly experiment?

Answer 12

Uninfected butterflies
*Think opposite of the independent

Question 13

What were the results of the butterfly experiment?

Answer 13

The infected butterflies had more eggs laid on the anti-parasitic plant (ACur.), and the uninfected butterflies were 50/50 for which plants they laid eggs on

Question 14

What was the second hypothesis for the butterfly experiment?

Answer 14

Infected/parasitic larva (caterpillars) consume anti-parasitic milkweed

Question 15

What was the design for the second hypothesis for the butterfly experiment?

Answer 15

Only infected/parasitic larva were given the choice to feed on ACur. or AIncarn. milkweed plant

Question 16

What were the results for the second hypothesis for the butterfly experiment?

Answer 16

No significant difference between which plant the infected larva consumed

Question 17

What were the dependent, independent, and controlled variable for the second hypothesis of the butterfly experiement?

Answer 17

-Dependent: which plant was consumed
-Independent: having the ACur. and AIncarn. plant available to consume
-Controlled: infected larva

Question 18

What does a compound microscopy mean it utilizes?

Answer 18

It utilizes a minimum of 2 lenses

Question 19

What two lenses does a compound microscopy use?

Answer 19

Occular and objective

Question 20

Does working distance increase or decrease as magnification increases?

Answer 20

Decreases

Question 21

Total magnification is ____ * ____

Answer 21

Eyepiece lens * Objective lens

Question 22

Diameter seen in the microscope is termed

Answer 22

Field of view (FOV)

Question 23

Thickness of specimen that may be seen in focus at one time is termed

Answer 23

Depth of field (DOF)

Question 24

Distance between the eye pieces is termed

Answer 24

Interpupillary distance

Question 25

Working distance is the distance between ___ ___ of lens and surface of cover ___ or ___ when it is in focus

Answer 25

eye piece
glass
specimen

Question 26

Larger depth of field has greater or smaller focus distance?

Answer 26

larger focus distance

Question 27

Smallest distance b/t 2 points on a specimen that can be distinguished as 2 separate entities is the microscope ___?

Answer 27

resolution

Question 28

What formula describes what resolution depends on?

Answer 28

d= 0.61 Y/ N.A

d= small distance
Y= wavelength
N=numerical aperture (n*sin(a))

Question 29

What sign describes half the acceptance angle of the objective lens

Answer 29

a

Question 30

What symbol describes the refractive index

Answer 30

N

Question 31

What is the conversion for N (refractive index)

Answer 31

C/ V

C= speed of light in vacuum
V= speed of light in given medium

Question 32

What is light gathering capabilities of the lens called?

Answer 32

Numerical aperture

Question 33

N for air?
N for immersion oil?

Answer 33

1
1.5

Question 34

Shorter wavelength = ___ energy= ____ N.A = ____ resolution

Answer 34

higher
greater
greater

Question 35

When air is the medium (n=1), light rays coming from the specimen are lost due to light ___ and ____

Answer 35

refraction
reflection

Question 36

What reduces light refraction and reflection?

Answer 36

Increasing “n” to 1.5 by adding immersion oil

Question 37

When magnification increases what happens to the Field of View (FOV)?

Answer 37

Smaller FOV

Question 38

What is the formula to calculate FOV?

Answer 38

HPD= (LPD * LPM)/ (HPM)

Question 39

What happens to the depth of focus when magnification is increased?

Answer 39

DOF gets smaller/ more shallow