Portage Learning / BIOD 171 / ALL EXAMS WITH ANSWERS 2022-2023, Exams of Nursing

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How many different types of amino acids are available from which to make proteins?

2. Define an essential amino acid.

An essential amino acid cannot be produced by the human body and as such must be take in

from the environment through alternative sources (i.e) food.

1. What are the two major types of nucleic acids and their roles?

There are two major types of nucleic acids: DNA (deoxyribonucleic acid) and RNA

(ribonucleic acid). Nucleic acids are chemical molecules that carry genetic information within

Exam 1.

True or False: A virus is considered a microorganism.

False. Viruses are not living and as such are not considered microorganisms. Viruses can, however, be classified as microbes, a more general term that includes microorganisms and viruses.

2. What is the smallest biological unit of life?

A cell.

3. At a generalized level, all cells are comprised of what?

Macromolecules* *A student may also answer: Proteins, Lipids, Nucleic acids and Polysaccharides but they must answer with all four to be fully correct.

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1. What are the two major types of nucleic acids and their roles?

DNA (deoxyribonucleic acid): Contains the genetic material as well as heredity characteristics

found in living organisms. RNA (ribonucleic acid): its role is for decoding the sequence of

heredity information found in DNA

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1. Complete the following RNA strand and indicate how many bonds are formed for each complementary pair:

3’ GGUCAUCG 5’

5’ CC AGC 3’

3’ GGUCAUCG 5’

5’ CCAGUAGC 3’

There are 2 bonds formed between A and U, and 3 bonds between G and C.

1. The plasma membrane (select all that are true):

A. Only restricts movement of materials into the cell

B. Is often a bilayer comprised of lipids

C. Cannot prevent essential nutrients from escaping

D. Contains hydrophobic tails pointing inward

B and D

2. Carbon, Hydrogen and Oxygen atoms come together to form what primary macromolecule? Give

an example.

Polysaccharides. Glucose, sucrose and cellulose are all acceptable answers.

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1. True of False: Eukaryotic cells do not have a nucleus

the cell. DNA contains a vast amount of hereditary information and is responsible for the

inheritable characteristics of living organisms. RNA is responsible for deciphering the

hereditary information in DNA and using it to synthesize proteins.

1. Cell walls are found in which of the following (select all that apply): A. Plants

B. Fungi

C. Bacteria

D. Mammalian cells E. Algae

A, B, C, E

2. The function of the ribosome is (select all that apply): A. Lipid synthesis

B. Protein synthesis

C. To produce energy (ATP) D. Protein modification and distribution

E. Waste disposal via hydrolytic enzymes

B. Ribosomes are located in the cytoplasm of prokaryotic cells and in the ER of eukaryotic

cells.

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1. A defining characteristic of fungi is the presence of chitin in the cell walls. Which of following also

contain chitin? Select all that apply.

A. Mushrooms

B. Bacteria

C. Yeast

D. Molds

A, C and D all contain chitin.

2. True or False: A defining characteristic of Protista is the inability of colonies to form tissue layers.

True.

1. Identify the following cellular components by matching the number with the description.

A. Cell wall B. Lysosome

C. Centriole

D. Rough endoplasmic reticulum

E. Plasma membrane F. Nucleus

G. Golgi apparatus

1 F

2 B

1. The catabolism of a single molecule of glucose goes through what 3 distinct transitions?

The breakdown of glucose goes through (1) Glycolysis then (2) Fermentation or Respiration

and finally through (3) the electron transport chain (ETC).

2. What is the most energetic transition in the catabolism of glucose?

The electron transport chain yields 34 ATP while both glycolysis and fermentation (or

respiration) each yield only 2 ATP.

3. Identify the reactants of the following chemical equation:

Glucose + 2NAD+ → 2 NADH + 2 Pyruvate + 2 ATP

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ATP has the energy (phosphate group) to donate while ADP can accept energy in the form of

a phosphate group. Thus, ATP can be reduced (ATP →ADP + Pi) while ADP can be built into

ATP (ADP + Pi →ATP).

2. An organism that derives its energy (generates ATP) from photons of light is called a?

Phototrophic microorganism.

An organism that derives its energy by removing electrons from elemental sulfur would be classified

as a?

Lithotroph

4. A reactive intermediate would be present in which phosphorylation process?

A. Photophosphorylation

B. Substrate-level phosphorylation

C. Oxidative phosphorylation

B. The chemical compound losing the phosphate group is referred to as the phosphorylated

reactive intermediate.

1. What is the primary byproduct of the TCA cycle? Select all that apply.

A. NAD+ B. FAD

C. NADH

D. FADH 2

C and D. The TCA cycle produces an abundance of reduced electron carriers (NADH and

FADH 2 ).

2. True or False. The reactants of the TCA cycle directly enter and fuel the electron transport system.

False. The products of the TCA cycle (reduced electron carriers) enter and drive the

production of ATP via the electron transport system.

1. In the absence of glucose, which of the following can be used as alternative energy sources?

Select all that apply.

A. Lactose

B. Nucleic acids

C. Carbohydrates

D. Lipids

A, C, D can all be used as alternative energy sources.

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The reactants are to the left of the arrow: Glucose and 2NAD+

4. The presence of what molecule ‘signals’ to the cell that glycolysis is about to start?

Glucose- 6 - phosphate (G6P)

5. True or False: In the absence of oxygen fermentation produces 2 ATP.

False. Fermentation only reduces NADH back to NAD+

1. How many turns (or repititions) of the Calvin Cycle are required to generate one molecule of glucose?

Six.

2. Complete the following equation by placing the appropriate numbers where indicated.

CO 2 + ATP + NADPH + H 20 → C 6 H 12 O 6 + ADP + NADP+

6 CO 2 + 18 ATP + 12 NADPH + 12 H 20 → C 6 H 12 O 6 + 18 ADP + 12 NADP+

1. Match the following reactions to its corresponding enzyme:

1. A + B → A-B

2. A-B → A + B

3. A-^ + B →A + B-

4. Ab + C → A + Cb

A- Lyases

B- Transferases

C- Oxioreductaces

D- Hydrolases

E- Ligases

F- Isomerases

1E 1. A + B → A-B

2A 2. A-B → A + B

Ligases Lyases

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2. True or False: Dark reactions can occur in the presence or absence of light.

True. The term ‘dark reactions’ (also known as the Calvin Cycle) simply denotes the second

stage in photosynthesis — dark reactions do not actually require darkness in order to occur.

. A micrometer is defined as

A. 10 -^3

B. 10 -^6

C.10-^9

D. 10 -^12

B. A micrometer is one-millionth of a meter.

2. True or False: A nanometer is longer than a micrometer.

False. A nanometer is 1,000 times smaller than a micrometer.

1. Resolution and contrast are two critical factors that influence your ability to see an object. Explain

each.

Resolution refers to the distance between two objects at which the objects still can be seen

as separate. Poor or low resolution means two (or more) objects may appear as one.

Contrast is the difference in light absorbance between two objects. Poor contrast gives a

high background and makes the visualization of multiple objects difficult. For instance, trying

to identify 2 dark colored objects at night (low light = low contrast) versus the same 2 objects

in the middle of a sunny afternoon (bright light against 2 dark objects = high contrast).

1. Assuming a constant (non-adjustable) light source power, identify the part of the microscope you

would adjust to limit the amount of light entering the microscope.

EXAM MODULE 3

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3C 3. A —^ + B → A + B —^ Oxioreductaces

4B 4. Ab + C → A + Cb Transferases

A. Stage

B. Fine Adjustment Knob

C. Iris Diaphragm

D. Neck

E. Condenser Lens

F. Eyepiece

G. Objective

H. Base

I. Coaxial Controls

1F

2D

1. For each of the following questions select from the list below the single best answer:

Phase-Contrast Dark Field

Fluorescence

Confocal

This type of microscope is best suited for visualizing GFP, RFP and YFP proteins.

Fluorescence

2. This type of microscope can provide detailed images of live cells without staining.

Phase-Contrast

3. This type of microscope is used to greatly increase the contrast between samples and background

by reflecting light off of the specimen.

Dark Field

4. This type of microscope is capable of capturing images in multiple focal planes, rendering a specimen in 3D

Confocal

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3B

4G

5A

6H

1. You want to observe the size and shape of a cell. What is the easiest staining technique that you could perform? Name at least one dye you would use during this process.

Simple stain. You could use any of the following: methylene blue, crystal violet, safranin or

fuschin.

2. You suspect a patient may have TB. Once a sample has been obtained it is sent off to the lab for an acid-fast stain. If the patient were infected with TB, describe what you would expect to see on the

stained slide.

You would expect to see red cells (TB+) on a blue background (TB negative).

3. True or False: If a patient is suspected of having malaria, a Giemsa stain would be an appropriate differential test to perform.

True. Giemsa stains are often used in the clinical setting to aid in the diagnosis of blood

parasites.

True or False: Growth media is best suited for distinguishing between two similar species of bacteria.

False. Growth media is designed to simply support (and not restrict) microbial growth.

2. A researcher is asked to determine which of two vials contains E coli and which contains

Salmonella. Knowing both are Gram-Negative while only one of them is capable of fermenting

lactose, which type of media would be best suited:

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True.

2. True or False: If you wish to study the motility of an organism you cannot heat fix, but you can

chemically fix the specimen.

False. Both heat and chemical fixation strategies will kill the cell, making motility

observations impossible.

1. True or False: LB agar is classified as a selective, non-differential media.

False. LB agar is the most basic type of agar and like LB media supports the growth of virtually all microbes without restriction.

2. What is agar used for in microbiology?

Agar is used to create a solid, smooth surface on which microbes can grow.

1. Match the following hemolytic class with its description of activity.

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1. Alpha hemolysis

B A. No hemolytic activity

2. Beta hemolysis

C B. Incomplete hemolytic activity

A. Growth media

B. Differential media

C. Selective media

D. Selective and Differential media

B. Differential media distinguishes between two, often related, microbes.

3. What are the requirements of a fastidious microbe?

A fastidious microbe is an organism with complex growth requirements such that if absent it

will not grow. Enriched medias thus contain these specific and essential nutrients required

for the growth of a particular subset of microorganisms.

1. What is the Gram status (Positive or Negative) of microbes growing on Eosin Methylene Blue (EMB) agar plates?

Gram-Negative. EMB plates specifically restrict the growth of Gram-Positive bacteria.

2. Mannitol salt agar will turn what color in the presence of the pathogenic strain Staphylococcus

aureus?

Yellow. Pathogenic Staph aureus will turn the agar from red to yellow.

1. What is the process of spreading a bacterial culture onto a petri dish?

Plating.

2. In order to visual individual colonies of bacteria would you culture your sample in a liquid media or

on a solid (agar) media? Why?

Solid (agar) media. The primary advantage is that cells are held into place. When grown in a

nutrient broth, bacterial cells can multiply but are free to move around in solution. When

grown on agar within a petri dish the fixed in such as way as to form colonies.

3. True or False? The visualization of colonies on a petri dish represents bacterial cells that have

often multiplied a million times over.

True. To form a bacterial colony the initial cell must have multiplied many times over, often greater than a million, in order for the naked eye to resolve it.

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non-pathogenic E. coli can ferment both soribitol and lactose. Therefore, colonies that

ferment (acidic conditions; non-pathogenic) can be differentiated from non-fermenters

(neutral to basic conditions; pathogenic).

1. True or False. The purpose of a quadrant streak is to expand a bacterial population.

False. The purpose of the quadrant streak is to generate individual colonies such that a

single (pure) bacterial sample can be isolated.

2. To be considered a ‘pure’ culture, the sample (1) can be traced back to a single cell and

(2)?

The culture must also be free from external contaminants. Simply put, a pure sample would

never contain multiple bacterial species (ie) Strep and Staph.

3. When performing a quadrant streak, the sample is spread across the plate in such as way as to

form what?

A dilution gradient is formed. The resulting gradient should always contain within it the

growth of individual colonies.

4. In what phase of a dilution streak would you expect to find the lowest concentration of bacteria, P

or P4?

P4 (Phase 4) would contain the lowest concentration of bacteria. The phases rank (from

highest to lowest), P1 > P2 > P3 > P4.

1. True or False. When performing a dilution streak a new (or sterilized) loop must be used for each

phase.

True. Failure to do so would prevent the establishment of a dilution gradient, as the same bacterial concentration would be spread across both phase regions.

2. In order to encourage growth of a slow growing microbe what might a researcher do during a phase dilution streak?

A researcher may either (1) opt to perform only a 3 - phase dilution streak or (2) pass the loop

through the previous phase multiple times (as opposed to only once).

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