BIOLOGY 1500 PRACTICE EXAM
QUESTIONS AND ANSWERS
You are examining a strand of nucleic acid and you want to know whether it is DNA
or mRNA. All of the following are appropriate questions to ask EXCEPT:
- Does it consist of a single strand or a double strand?
- If a nucleotide has a base A, what nucleotide will it pair with?
- Does it contain nucleotides with the base T?
- Does it contain instructions for building protein molecules? - ANSWER-Answer =
Does it contain instructions for building protein molecules?
How does a molecule of Hb in the lungs compare with a molecule of Hb in the active
muscles?
- The Hb subunits are farther apart from each other in the lungs compared to in the
muscles.
- While in the lungs, the Hb is located outside of the blood vessels and inside the air
space of the alveoli; but in the muscles, the Hb is located inside the red blood cells.
- More heme groups attach to the Hb when it is in the lungs, allowing more O2 to
bind.
- In the lungs, the heme groups fold to the outside of the protein for easy release of
CO2 and binding of O2 - ANSWER-Answer = The Hb subunits are farther apart from
each other in the lungs compared to in the muscles.
In the relationship between Hb and oxygen, cooperative binding refers to:
- Each time a Hb molecule binds to an O2, it makes it easier for another O2 to bind
to the same Hb molecule.
- As soon as one Hb molecule binds to O2, the other Hb molecules in that red blood
cell can bind more easily to O2.
- Hb is attracted to O2, and O2 is attracted to Hb, so the two molecules are said to
'cooperate' in binding to each other.
- One O2 can bind to multiple Hb molecules at the same time, increasing the
efficiency of transporting Hb through the body. - ANSWER-Answer = Each time a Hb
molecule binds to an O2, it makes it easier for another O2 to bind to the same Hb
molecule.
The Hb-O2 dissociation curve is sigmoidal in shape. Which of the following is an
advantage of the sigmoidal shape over a linear shape?
- It's easier to shift a sigmoidal curve to the left or right, compared to shifting a
straight line.
- The molecules of Hb can move more quickly along the steepest part of the
sigmoidal curve than they would along a straight line.
- A small drop in PO2 can cause a large drop in the percentage of Hb molecules that
are bound to O2 in the body.
QUESTIONS AND ANSWERS
You are examining a strand of nucleic acid and you want to know whether it is DNA
or mRNA. All of the following are appropriate questions to ask EXCEPT:
- Does it consist of a single strand or a double strand?
- If a nucleotide has a base A, what nucleotide will it pair with?
- Does it contain nucleotides with the base T?
- Does it contain instructions for building protein molecules? - ANSWER-Answer =
Does it contain instructions for building protein molecules?
How does a molecule of Hb in the lungs compare with a molecule of Hb in the active
muscles?
- The Hb subunits are farther apart from each other in the lungs compared to in the
muscles.
- While in the lungs, the Hb is located outside of the blood vessels and inside the air
space of the alveoli; but in the muscles, the Hb is located inside the red blood cells.
- More heme groups attach to the Hb when it is in the lungs, allowing more O2 to
bind.
- In the lungs, the heme groups fold to the outside of the protein for easy release of
CO2 and binding of O2 - ANSWER-Answer = The Hb subunits are farther apart from
each other in the lungs compared to in the muscles.
In the relationship between Hb and oxygen, cooperative binding refers to:
- Each time a Hb molecule binds to an O2, it makes it easier for another O2 to bind
to the same Hb molecule.
- As soon as one Hb molecule binds to O2, the other Hb molecules in that red blood
cell can bind more easily to O2.
- Hb is attracted to O2, and O2 is attracted to Hb, so the two molecules are said to
'cooperate' in binding to each other.
- One O2 can bind to multiple Hb molecules at the same time, increasing the
efficiency of transporting Hb through the body. - ANSWER-Answer = Each time a Hb
molecule binds to an O2, it makes it easier for another O2 to bind to the same Hb
molecule.
The Hb-O2 dissociation curve is sigmoidal in shape. Which of the following is an
advantage of the sigmoidal shape over a linear shape?
- It's easier to shift a sigmoidal curve to the left or right, compared to shifting a
straight line.
- The molecules of Hb can move more quickly along the steepest part of the
sigmoidal curve than they would along a straight line.
- A small drop in PO2 can cause a large drop in the percentage of Hb molecules that
are bound to O2 in the body.
