BIO 392 Exams 1-7 | 134 Study Questions And Answers |
Complete Solutions Rated A+
Make TWO corrections to the bolded definition of Homeostasis, below (like in class).
1. Limit your identification of mistakes to 1-3 words at a time. Quote the mistake.
2. Limit your corrections to 2-12 words each. Quote the correction. I'll likely only read and count the words in
the quotes.
3. Example: If the answer you were evaluating was, Homeostasis is balance outside the body, one correction
would be, "Balance" (1 word) should be "Steady state" (2 more words). Total: 5 words.
4. As noted in class, I will not give credit for simply stating a definition of homeostasis.
Homeostasis is a state of equilibrium in which internal and external variables are kept constant. ANS
Correction #1: equilibrium. Instead of equilibrium, the definition should say steady state. Equilibrium is not
reached with homeostasis, homeostasis surrounds a set point and does minorly fluctuate (but is still considered
normal).
Correction #2: constant. Instead of constant, the definition could say relatively constant. Homeostasis is not a
fixed constant throughout time, but is allowed to fluctuate. If a variable fluctuates too high or too low, the body
works to return that variable back to the set point.
Carefully read the following description of the homeostatic regulation of plasma calcium. Refer back as
needed. Apply Kelty's rule to start at the effect, response end of reflex and work backward.
Because a computer is grading, spelling counts.
Decreased plasma Ca is detected by parathyroid cells. This change stimulates the parathyroid cells to release
the peptide hormone parathyroid hormone (PTH) into the blood. The blood stream carries PTH throughout the
body, but most notably to bone. At bone tissue, PTH stimulates osteoclasts (a type of bone cell) to break down
bone's mineral matrix, thereby releasing Ca from the tissue intro the blood and elevating circulating Ca levels.
In the preceding example,
Elevating plasma Ca in this reflex = __ [A]__ feedback
The effector is/are: __[B]__
The efferent pathway: __[C]__
The efferent messenger: __[D]__ ANS A negative
B osteoclasts
C blood stream
,D PTH
In labor,
1. the baby's head pressing against the cervix activates mechanoreceptors.
2. These sensors produce nerve impulses that travel through afferent neurons to the hypothalamus.
3. The hypothalamus, causes the posterior pituitary gland to release the hormone oxytocin into the blood
stream.
4. The blood stream carries the oxytocin to smooth muscle in the uterus, causing it to increase contractions.
5. As a result, more pressure is put on the baby, and thus the cervix, causing increased mechanoreceptor
activation go back to step one and keep repeating, with amplification, each time.
This reflex provides an example of _____. ANS Positive feedback
What is signal transduction? ANS Conversion of the information carried by an extracellular messenger (a
first messenger like a hormone) into a form that can carry the information in the cell and thereby affect a cell
response
Which is NOT a second messenger in the phospholipase C pathway?
a. Protein Kinase C
b. Calcium
c. IP3
d. DAG ANS a. Protein Kinase C
Let's say I am trying to evaluate the observational hypothesis that the cAMP path is involved the response of
liver cells to the hormone glucagon (we already know glucagon causes the liver cells to break down glycogen
and thereby release glucose).
I run an experiment where:
1. In Group 1: I measure baseline release of glucose (cells in culture medium only). Result: almost no glucose
release.
2. In Group 2: I add glucagon to liver cells and measure their glucose release. Result: massive increase in
glucose release; no surprise here.
3. In Group 3: I add a blocker of the glucagon receptor to the saline, but no glucagon. Result: No change in
baseline glucagon release.
, 4. In Group 4: I add glucagon and the glucagon receptor blocker: Result: slightly more glucose release than in
plain culture medium, but vastly less than glucagon alone.
True or False: This experiment directly demonstrates/supports the involvement of the ANS False
We have found that administration of PTH increases Ca reabsorption at the kidney and think that the PLC
pathway is involved in this response since we see that PTH activates PLC paths in other tissues. Thus, we
hypothesize that (in addition to its actions on bone) PTH helps maintain Ca homeostasis by activating the PLC
path in kidney cells thereby increasing their ability to reabsorb Ca (from the from the fluid filtered into the
kidneys, back into the blood)
1. What is one prediction one would test to evaluate the involvement of the PLC path in the kidney's regulation
of Ca?
2. What is a second prediction one would test to evaluate the involvement of the PLC path in the kidney's
regulation of Ca?
Rem: Each prediction should take the form, "doing this manipulation will cause this effect."
Make sure your predictions are specific to the PLC pathway.
Note: The phrases "... if the hypothesis is correct." and "... compared ANS Blocking PTH or the PTH
receptor only tells one that activation of the PTH receptor increases Ca reabsorption; it does not evaluate
involvement of the PLC path, activation of PLC, etc.
Adding PTH, or activating the PTH receptor only supports what is already known, that activation of the PTH
receptor causes increased Ca reabsorption. Activating the receptor without directly manipulating the PLC path,
or at least measuring some aspect of the pathway itself tells us nothing about the involvement of the PLC path.
Two ligands bind the same receptor. The data above were from each ligand applied separately using the same
number of receptors in each solution and the same range of ligand concentrations.
A. Based on the data above, which ligand exhibits a greater affinity for the receptor?
B. If both ligands are present in equal, saturating concentration, which will bind more receptors? ANS A, A
(THIS IS A GRAPH QUESTION)
A solution contains 0.5844g% Nacl, or 5.844 g of NaCl/L.
The FW of NaCl is 58.44 g/mol.
Complete Solutions Rated A+
Make TWO corrections to the bolded definition of Homeostasis, below (like in class).
1. Limit your identification of mistakes to 1-3 words at a time. Quote the mistake.
2. Limit your corrections to 2-12 words each. Quote the correction. I'll likely only read and count the words in
the quotes.
3. Example: If the answer you were evaluating was, Homeostasis is balance outside the body, one correction
would be, "Balance" (1 word) should be "Steady state" (2 more words). Total: 5 words.
4. As noted in class, I will not give credit for simply stating a definition of homeostasis.
Homeostasis is a state of equilibrium in which internal and external variables are kept constant. ANS
Correction #1: equilibrium. Instead of equilibrium, the definition should say steady state. Equilibrium is not
reached with homeostasis, homeostasis surrounds a set point and does minorly fluctuate (but is still considered
normal).
Correction #2: constant. Instead of constant, the definition could say relatively constant. Homeostasis is not a
fixed constant throughout time, but is allowed to fluctuate. If a variable fluctuates too high or too low, the body
works to return that variable back to the set point.
Carefully read the following description of the homeostatic regulation of plasma calcium. Refer back as
needed. Apply Kelty's rule to start at the effect, response end of reflex and work backward.
Because a computer is grading, spelling counts.
Decreased plasma Ca is detected by parathyroid cells. This change stimulates the parathyroid cells to release
the peptide hormone parathyroid hormone (PTH) into the blood. The blood stream carries PTH throughout the
body, but most notably to bone. At bone tissue, PTH stimulates osteoclasts (a type of bone cell) to break down
bone's mineral matrix, thereby releasing Ca from the tissue intro the blood and elevating circulating Ca levels.
In the preceding example,
Elevating plasma Ca in this reflex = __ [A]__ feedback
The effector is/are: __[B]__
The efferent pathway: __[C]__
The efferent messenger: __[D]__ ANS A negative
B osteoclasts
C blood stream
,D PTH
In labor,
1. the baby's head pressing against the cervix activates mechanoreceptors.
2. These sensors produce nerve impulses that travel through afferent neurons to the hypothalamus.
3. The hypothalamus, causes the posterior pituitary gland to release the hormone oxytocin into the blood
stream.
4. The blood stream carries the oxytocin to smooth muscle in the uterus, causing it to increase contractions.
5. As a result, more pressure is put on the baby, and thus the cervix, causing increased mechanoreceptor
activation go back to step one and keep repeating, with amplification, each time.
This reflex provides an example of _____. ANS Positive feedback
What is signal transduction? ANS Conversion of the information carried by an extracellular messenger (a
first messenger like a hormone) into a form that can carry the information in the cell and thereby affect a cell
response
Which is NOT a second messenger in the phospholipase C pathway?
a. Protein Kinase C
b. Calcium
c. IP3
d. DAG ANS a. Protein Kinase C
Let's say I am trying to evaluate the observational hypothesis that the cAMP path is involved the response of
liver cells to the hormone glucagon (we already know glucagon causes the liver cells to break down glycogen
and thereby release glucose).
I run an experiment where:
1. In Group 1: I measure baseline release of glucose (cells in culture medium only). Result: almost no glucose
release.
2. In Group 2: I add glucagon to liver cells and measure their glucose release. Result: massive increase in
glucose release; no surprise here.
3. In Group 3: I add a blocker of the glucagon receptor to the saline, but no glucagon. Result: No change in
baseline glucagon release.
, 4. In Group 4: I add glucagon and the glucagon receptor blocker: Result: slightly more glucose release than in
plain culture medium, but vastly less than glucagon alone.
True or False: This experiment directly demonstrates/supports the involvement of the ANS False
We have found that administration of PTH increases Ca reabsorption at the kidney and think that the PLC
pathway is involved in this response since we see that PTH activates PLC paths in other tissues. Thus, we
hypothesize that (in addition to its actions on bone) PTH helps maintain Ca homeostasis by activating the PLC
path in kidney cells thereby increasing their ability to reabsorb Ca (from the from the fluid filtered into the
kidneys, back into the blood)
1. What is one prediction one would test to evaluate the involvement of the PLC path in the kidney's regulation
of Ca?
2. What is a second prediction one would test to evaluate the involvement of the PLC path in the kidney's
regulation of Ca?
Rem: Each prediction should take the form, "doing this manipulation will cause this effect."
Make sure your predictions are specific to the PLC pathway.
Note: The phrases "... if the hypothesis is correct." and "... compared ANS Blocking PTH or the PTH
receptor only tells one that activation of the PTH receptor increases Ca reabsorption; it does not evaluate
involvement of the PLC path, activation of PLC, etc.
Adding PTH, or activating the PTH receptor only supports what is already known, that activation of the PTH
receptor causes increased Ca reabsorption. Activating the receptor without directly manipulating the PLC path,
or at least measuring some aspect of the pathway itself tells us nothing about the involvement of the PLC path.
Two ligands bind the same receptor. The data above were from each ligand applied separately using the same
number of receptors in each solution and the same range of ligand concentrations.
A. Based on the data above, which ligand exhibits a greater affinity for the receptor?
B. If both ligands are present in equal, saturating concentration, which will bind more receptors? ANS A, A
(THIS IS A GRAPH QUESTION)
A solution contains 0.5844g% Nacl, or 5.844 g of NaCl/L.
The FW of NaCl is 58.44 g/mol.
