Molecular Biology Lab Exam 1

Front 1

Scientific Method

Back 1

1. Observation
2. Hypothesis
3. Experiment
4. Theory
5. Law

Front 2

Hypothesis

Back 2

A testable explanation for a set of observations based on the available data and guided by inductive reasoning. A hypothesis is narrower in scope than a theory. A hypothesis can be falsified but never be proven true.

Front 3

Theory

Back 3

An explanation that is broader in scope than a hypothesis, generates new hypotheses, and is supported by a large body of evidence.

Front 4

Control

Back 4

Treatment that eliminates the independent variable or sets it at a standard value.

Front 5

Independent Variable

Back 5

What the investigator varies in the experiment (for example, time, pH, temperature, concentration)

Front 6

Dependent Variable

Back 6

What the investigator measures, counts, or records; what is being affected in the experiment.

Front 7

Procedure

Back 7

Process used to measure the dependent variable.

Front 8

Level of Treatment

Back 8

Appropriate values to use for the independent variable.

Front 9

Replication

Back 9

Number of times the experiment is repeated.

Front 10

Prediction

Back 10

Statement of the expected results of an experiment based on the hypothesis.

Front 11

Allometry (allometric growth)

Back 11

The phenomenon whereby parts of an organism grow at different rates, or disproportionate growth of a part in relation to the entire organism. (head)

Front 12

Isometric Growth

Back 12

When two parts grow at the same rate. (arms)

Front 13

A study of 10,000 women revealed that women with breast cancer had a history of heavier antibiotic use than women who did not have breast cancer. What are the possible explanations for this correlation?

Back 13

The antibiotics might be causing the cancer. A weak immune system could cause bacterial infections and cancer.

Front 14

Malaria cases in South Africa before, during, and after DDT spraying.

Back 14

Independent Variable: Time measured in years.
Dependent Variable: Number of malaria cases.

Front 15

The relationship of beak depth in ground finches and the maximum hardness of seeds they can crack.

Back 15

The harder the seeds, the larger the beak depth.

Front 16

During the drought of 1977, which group of ground finches were more successful in finding food and reproducing, those with large beaks or those with small beaks?

Back 16

Those with large beaks survived better because they were better equipped in finding food.

Front 17

Speed test for wild cheetahs (Hypothesis, collar experiment and conclusion)

Back 17

Hypothesis- Its success as a predator also hinges on its lightning reflexes and its ability to accelerate faster than a Ferrari. (with a burst of speed un-rivalled in the natural world, the cheetah brings down its next meal)
Collar Experiment- Armed with lightweight solar-powered collars fitted with GPS and inertial technologies, a team led by Alan Wilson at London's Royal Veterinary College precisely tracked wild cheetahs during hunting.
Conclusion- Both agility and maneuverability turn out to be at least as important to the cheetahs as speed.

Front 18

Ocular Lens

Back 18

Eyepiece lens

Front 19

Nosepiece

Back 19

Holds the objective lenses

Front 20

Objective Lenses

Back 20

Scanning Lens- 4X
Low power lens-10x
High power lens- 40x

Front 21

Mechanical stage

Back 21

supports the specimen being viewed

Front 22

Iris Diaphragm

Back 22

Controls the width of the circle of light and, the amount of light passing through the specimen.

Front 23

Condenser lens

Back 23

Used to focus the light from the lamp through the specimen to be viewed.

Front 24

Coarse and fine adjustment knobs

Back 24

Used to adjust the distance between the stage and specimen.

Front 25

Amoeba (unicellular-aquatic organism)

Back 25

Nucleus- The grayish, football-shaped body that is somewhat granular in appearance.
Cytoplasm- contains the organelles
Cell membrane- the boundary that separates the organism from its surroundings.

Front 26

Volvox (multicellular-aquatic green alga)

Back 26

In this organism, the individual cells are interconnected by cytoplasmic strands to form a sphere. Small clusters of cells, called daughter colonies, are specialized for reproduction.

Front 27

Spirogyra (green algae)

Back 27

Cell wall- rigid outer framework
cytoplasm- contains the contents of the cell
Chloroplasts- green, spherical organelles within the cytoplasm. Contain the pigment chlorophyll involved in photosynthesis.
Nucleus- spherical organelle within the nucleus that controls the cells metabolism and division.

Front 28

Epithelial cells

Back 28

Cell Membrane- The boundary that separates the cell from its surroundings.
Nucleus- Large, circular organelle near the middle of the cell
Cytoplasm- Granular contents of the cell, exclusive of the nucleus.

Front 29

What characteristics do all eukaryotic cells have in common?

Back 29

Large, contain complex organelles, DNA in nucleus.

Front 30

What cellular features differentiate plants from animals?

Back 30

Cell walls, chloroplasts

Front 31

How are the structures that are unique to plants important to their success?

Back 31

Cell walls- provide structure and support
Chloroplasts- photosynthesis

Front 32

Review the criteria used to distinguish between colonial and multicellular organisms. Why is Volvox now considered multicellular?

Back 32

Two different cell types carrying out two different functions. Maintenance and reproduction (daughter cells)

Front 33

We often imply that multicellular organisms are more advanced than unicellular or colonial organisms. Explain why this is not true.

Back 33

The less advanced prokaryotes have been around for a lot longer and continue to evolve and thrive.

Front 34

Eukaryotic cells

Back 34

True nucleus containing chromosomes with genetic material separated from the remainder of the cell by the nuclear envelope.

Front 35

Prokaryotic cells

Back 35

Genetic material is not bound by a nuclear envelope and no membrane organelles are present.

Front 36

Diffusion

Back 36

Movement of molecules from an area of higher concentration to an area of lower concentration.

Front 37

Osmosis

Back 37

The diffusion of water through a selectively permeable membrane from a region where it is highly concentrated to a region where the concentration is lower.

Front 38

Hypertonic Solution

Back 38

Has a greater concentration of solutes that cannot cross the membrane (non-penetrating solutes) than the solution on the other side of the membrane (higher osmolarity.)

Front 39

Hypotonic Solution

Back 39

Has a lower concentration of non-penetrating solutes, or a lower osmolarity, than the solution on the other side of the membrane.

Front 40

Isotonic Solution

Back 40

When the two solutions are in equilibrium, the osmolarities are equal, and the concentration of non-penetrating solutes are equal on both sides of the membrane.

Front 41

Concentration Gradient

Back 41

Difference in concentration

Front 42

Dynamic Equilibrium

Back 42

Molecules moving equally in all directions

Front 43

Hypothesize about the selectively permeability of dialysis tubing to the substances being used.

Back 43

Molecules will diffuse through pores in the dialysis tubing based on their size.

Front 44

Predict the results of the I2KI and the Benedict's test based on your hypothesis (if/then).

Back 44

If the molecules are small enough then they will pass through the dialysis tubing.

Front 45

What is the significance of the final colors and the colors after the benedict's test?

Back 45

Positive test for sugar in the bag and positive test for sugar in the beaker.
Yellow in the beaker means no starch in the beaker.
Purple in the bag means starch in the bag.
The starch molecules were to big to pass through the bag and the sugar molecules were small enough to pass through the bag.

Front 46

Predict the size of I2KI molecules relative to glucose and starch.

Back 46

In relation to starch I2KI molecules were smaller. In relation to glucose the I2KI molecules were the same size or smaller.

Front 47

What is the I2KI for?

Back 47

To test for the presence of starch. (turns purple or black)

Front 48

Benedict's Reagent

Back 48

Turns green, orange, or orange red if a reducing sugar is present.

Front 49

Enzyme

Back 49

Biological catalysis that speeds up the reaction without being used or altered in the reaction. (Tyrosinase)

Front 50

Substrate

Back 50

The material with which the enzymes reacts. (Pyrocatechol)

Front 51

Active Site

Back 51

Part of the enzyme that binds with the substrate.

Front 52

Cofactors

Back 52

Nonprotein substances that usually bind to the active site on the enzyme and are essential for the enzyme to work.

Front 53

Organic Cofactors

Back 53

Coenzymes

Front 54

Inhibitor (competitive and noncompetitive)

Back 54

Chemicals that shut off enzyme activity.

Front 55

Both high and low temperatures reduced the amount of color (product) produced. The cause of the reduction is different in both cases. Explain

Back 55

Extremely High: De-natures the enzyme.

Front 56

Extremely Low:

Back 56

Slows down the reaction.

Front 57

If you were to look at the three tubes involved in the enzyme concentration experiment 24 hrs. after the experiment, how would the colors compare?

Back 57

They would all be the same as time compensates for compensation.

Front 58

At what pH was the enzyme most effective?

Back 58

pH 7 was the most effective, pH of 5 works but not as effective.

Front 59

Explain why changing the pH alters the effectiveness of the enzyme.

Back 59

When you change the pH you mover the enzyme out of the optimal range.

Front 60

Alcohol Fermentation

Back 60

Begins with glycolysis, a series of reactions breaking down glucose into two molecules of pyruvate with a net yield of 2 ATP and 2 NADH molecules. In anaerobic environments, in two steps the pyruvate (a 3-carbon molecule) is converted to ethyl alcohol (ethanol, a 2-carbon molecule) and CO2

Front 61

Cellular respiration

Back 61

C6H12O6 +6O2--->6H2O +CO2

Front 62

Rate of Fermentation

Back 62

A series of enzymatic reactions can be affected by several factors such as concentration of yeast, concentration of glucose, or temperature.

Front 63

Explain the experimental design. What is the purpose of each test tube? Which are the control Tubes?

Back 63

Control- Tubes 1 and 2
Experimental- Tube 3 and 4

Front 64

Which test tube had the highest rate of fermentation?

Back 64

Tube 4 had the highest rate of fermentation because it had the greatest amount of yeast.

Front 65

Which test tube had the lowest rate of fermentation?

Back 65

Test tube one had no fermentation because there was no yeast.
Test tube two had no glucose and could only ferment a small amount if any from residuals.

Front 66

Why were different amounts of water added to each fermentation solution?

Back 66

To keep the tubes at the same volume. Vary the amount of water to maintain the mixture level.

Front 67

Your mother has been baking bread all afternoon and says not to slam the oven door. Why?

Back 67

The bread will fall because the CO2 will escape.

Front 68

Two characteristics of natural wines are that they have a maximum alcohol content of 14% and are "sparkling" wines. Explain

Back 68

CO2 causes the sparkle and alcoholic content above 14% will kill the yeast.

Front 69

Photosynthesis

Back 69

Light energy is transformed into chemical energy. That chemical energy is used to synthesize organic compounds (glucose) from CO2, and in the process water is used and O2 is released.

Front 70

Chlorophyll a

Back 70

Absorbs wavelengths between 430 - 662 nm (violet-blue and red), primary pigment blue green in color, participates directly in the light reactions

Front 71

Chlorophyll b

Back 71

Absorbs wavelengths between 453 - 642 nm (purple-blue, yellow-red), accessory pigment olive green in color, that transfers energy to chlorophyll A

Front 72

Carotenoid

Back 72

Absorbs wavelengths between 450 - 550 nm (violet and blue-green) , accessory pigment yellow or orange in color, broaden the spectrum of colors that can drive photosynthesis

Front 73

Xanthophyll

Back 73

Absorbs wavelengths between 450 - 550 nm

Front 74

Which pigment is the most important in the process of photosynthesis?

Back 74

Chlorophyll A because it absorbs the greatest amount of visible light.

Front 75

Chlorophyll b and carotenoids are called accessory pigments. Why

Back 75

They expand the spectrum and they transfer their energy back to chlorophyll a

Front 76

How can features of food crops be improved

Back 76

Increase pigments-chloroplasts, increase surface area of the leaves, make it more drought and pest resistant.

Front 77

In response to a shorter day and cooler temperatures what happens to the trees?

Back 77

As chlorophyll production shuts down due to less light and photosynthesis, the accessory pigments take over by absorbing light in a different parts of the spectrum turning the leaves on the trees yellow and orange.

Front 78

Paper chromatography experiment

Back 78

Chlorophyll b is the most polar (least soluble) and moves the least while beta carotene is the least polar (most soluble) and moves the most.