Vent...A&P test borders on unfair

[TeleMad]

Just took my third A&P lecture exam and I think it came out being somewhere between unreasonable and unfair.

 

1) The test contained 3 questions, for a total of 9 out of 270 points, that were never covered in lecture (nor were they mentioned in any of the labs). That basically drops someone who knows literally everything from the lecture material down to a 96.7.

 

2) The teacher has True/False questions that you might as well just guess at. For example, she'll has 5 facts in the statement correct but one work will be slightly off, making it false in her mind. That's fair enough, but NOT WITH HER. She makes mistakes and one can't guess whether it's her just making a mistake of if she actually meant to type a wrong term. As one example I partly remember, she has a statement along the lines of "The cardiac sulcus drains the coronary vessels". I put false because in lecture she stated that the cardiac SINUS drains the coronary vessels, and the sulcus and the sinus are not the same thing. But she marked my answer wrong. Now how is someone supposed to know if she intentionally put the wrong term - sulcus instead of sinus - of if she goofed?

 

So with the above two characteristics, I'd say one is likely to score 95 or lower even if he knows the lecture material frontwards and backwards. Is that fair???

 

 

 

3) She mislead us about what would be on the test. In addition to all the lectures she gave, she had us spend a two-hour session working through a CD on gas transport and gas exchange, each person individually, without any indication of what specifically would be on the exam: just her stating that the material would be on the exam. So I took fairly extensive notes... here they are (it may not seem like much for 2 hours work, but the CD made had lots of visuals with little text on each 'page', so the ratio of printed vs. overall material needed to learn is not near 100%, and we were using slow laptops to boot).

 

Gas Transport

 

1) What are the two fates of the O2 that diffuses out from alveoli? What is the percentage of the total oxygen for each?

dissolves in plasma = 1.5%

combines with hemoglobin = 98.5%

 

2) As the ‘saturation’ of a single hemoglobin molecule increases, an affect known as _____ occurs in which the hemoglobin molecule’s _____ for oxygen _____.

cooperative binding

affinity

increases

 

3) List 5 factors that affect hemoglobin’s saturation: for each, indicate what an increasing magnitude of the factor would do to Hb’s saturation.

a) PO2: raising PO2 raises Hb’s saturation

;) pH: raising pH raises Hb’s saturation

c) temperature: raising temperature lowers Hb’s saturation

d) PCO2: raising PCO2 lowers Hb’s saturation

e) high BPG: raising BPG lowers Hb’s saturation

 

4) What is the reversible reaction that occurs between oxygen and hemoglobin?

Hb + O2 = HbO2

 

5) What is the name for HbO2?

oxyhemoglobin

 

6) At sea level, the partial pressure of oxygen is _____; at high altitude it might be about _____. Also, give the hemoglobin saturation for both. What is there to note about these pairs of values?

100mmHg: 98% saturation

80mmHg: 95% saturation

the small difference in saturation, despite a relatively large change in PO2

 

7) The PO2 of an exercising muscle might be _____, with a hemoglobin saturation of _____. List several reasons the value is so low.

20mmHg

35%

exercise:

lowers pH

raises temperature

raises PCO2

raises BPG

 

8) What are the three fates of the CO2 that diffuses out from tissue cells? What is the percentage of the total carbon dioxide for each?

dissolves in plasma = 7%

diffuses into RBCs and combines with (globin portion of) hemoglobin = 23%

diffuses into RBCs and is converted to HCO3- (bicarbonate) = 70%

 

9) What is the reversible reaction for carbon dioxide combining with hemoglobin?

Hb + CO2 = HbCO2

 

10) What is the name for HbCO2?

carbaminohemoglobin

 

 

11) What is the reversible reaction for carbon dioxide being converted to bicarbonate.

CO2 + H2O = H2CO3 = H+ + HCO3-

 

12) What enzyme is involved in the conversion of CO2 into HCO3-, and in which of the two reactions

(CO2 + H2O = H2CO3 or H2CO3 = H+ + HCO3-) does it function?

carbonic anhydrase

the first reaction (CO2 + H2O = H2CO3)

 

13) What happens to the liberated H+ produced during the conversion of carbon dioxide into bicarbonate?

combines with Hb to form HHb

 

14) What happens to the bicarbonate that is produced from carbon dioxide? What is this process called?

HCO3- is exchanged across the plasma membrane for Cl-

chloride shift

 

15) What does the bicarbonate in the plasma do?

acts as a buffer

 

16) O2 loading facilitates CO2 unloading: this is known as the _____.

Haldane effect

 

17) Decreased pH increases O2 unloading: this is known as the _____.

Bohr effect

 

 

 

Gas Exchange

 

1) What are the 4 main gases that make up air, and what is each one’s percentage of the total.

N2 = 78.6%

O2 = 20.9%

H2O = 0.46%

CO2 = 0.04%

 

2) How would you find the partial pressures for the above gases?

multiply each gas’s percentage by 1 atm (where 1 atm = 760mmHg)

Example: PN2 = 78.6% x 760mmHg = 597mmHg

 

3) What is Dalton’s law?

The total pressure exerted by a gas solution is equal to the sum of the individual gas’s partial

pressures: Ptotal = Pgas1 + Pgas2 + … Pn

 

4) What is Henry’s law?

The amount of a gas that will dissolve in a liquid is directly proportional to (a) the partial pressure

of that gas, and (;) the solubility of that gas.

 

5) Which is more soluble in blood, O2 or CO2?

CO2

 

6) What is external respiration?

exchange of O2 and CO2 that occurs between the alveoli and the pulmonary capillaries

 

7) What three factors affect external respiration?

a) surface area and structure of respiratory membrane

;) partial pressure gradients

c) matching alveolar airflow to pulmonary capillary blood flow

 

8) What three factors cause the partial pressures in alveoli to differ from the atmosphere’s?

a) humidification of inhaled air

;) gas exchange between alveoli and pulmonary capillaries

c) mixing of new and old air (since alveoli don’t completely empty)

 

9) _____ facilitates gas exchange by maintaining alveolar airflow proportional to pulmonary capillary blood flow.

ventilation-perfusion coupling

 

10) In a high-airflow condition, _____ is high so the _____ dilate in order to _____.

PO2

arterioles

bring more blood to alveoli to pick up oxygen

 

11) In a low-airflow condition, _____ is high so the _____ dilate in order to _____.

PCO2

bronchioles

eliminate excess CO2 from alveoli

 

12) What is internal respiration?

exchange of O2 and CO2 that occurs between body tissues and the systemic capillaries

 

13) What are the partial pressures for O2 and CO2 for both body tissues and systemic capillaries?

body tissues: PO2 = 40mmHg PCO2 = 45mmHg

systemic capillaries: PO2 = 100mmHg PCO2 = 40mmHg

 

And you know how much of that, which I had completely memorized, was on the exam? NONE.

 

4) She doesn't review for exams, and then only a small fraction of the material ends up on it This is not unfair, but is it reasonable? After all, I have 36 pages of lecture notes, that are very detailed, for this exam. I memorzied and learned the heck out of all of that material out of which probably only 25% to 30% or so ended up on the exam. (Note I said learned, not just memorized. She always has 2 essays - which we don't know what they will be on - that are worth a huge fraction of the overall grade: this test's came to 90 points out of 270. Memorizing answers to indidivual questions won't cut it: you have to know how everything relates and how to synthesize facts into a coherent essay - that contains complete sentences, proper paragraphs, correct spelling, including all technical terms, proper punctuation, and so on).

 

5) Finally, although this is not unfair, it seems a bit unreasonable to me. At the beginning of the lecture material for this test she handed out a one-page terms sheet. On the front were about 10 gas laws related to respiration and on the back were about 10 terms related to respiratory volume and capacities. She said to the effect, "You may know these gas laws from chemistry, but they are stated a bit differently in the study of the respiratory system." Never again was the handout mentioned or referenced. I looked over it once before the test, mainly at the gas laws since that is the only part she mentioned. And guess what. About 10% of the points came from that handout, and most of those were from the volume/capacity side. Is that fair? Sure, I guess. Is it reasonable? I don't know.

 

This test is going to hurt my average in that class.

[C1ay]

Funny, when I saw your heading I was expecting a rant on the Airframe & Powerplant Test required for aircraft technicians.

[Fishteacher73]

I always loved the absurd test....My Organic II professor gave a final that had a class average of 17 out of 150.... Either you can say it was a poor test or poor teaching, but if that many people score that poorly on your exam, something is up. B)

 

another time it was in my bio lab I had a costaRica grad student teaching the lab. He explained that there was a term we needed to know for the exam in lecture, but he did not know what it was in English....That was helpful too... ;)

[TeleMad]

I always loved the absurd test....My Organic II professor gave a final that had a class average of 17 out of 150.... Either you can say it was a poor test or poor teaching, but if that many people score that poorly on your exam, something is up. ;)

 

Okay, you win :-) My test wasn't THAT bad.

 

What bothers me is that throughout my first BS and so far on my second BS I have maintained a perfect 4.0 cumulative GPA, and I want to keep it. But I don't know if I can by taking her tests.

 

So far in her class before this last test I had a 93, 93, 92 (none of which reflect the actual degree to which I knew the lecture and lab material). So with half the exams in I had only a 92.67 average: that's cutting it kind of close. On this last also-unreasonable, but even-more-unreasonable, test I estimated that I made about an 85 (since I couldn't answer any of the questions dealing with the lung volume/capacity side of the handout, in addition to the 'expected' loss of points due to her phrasing and asking questions not covered). Add that last one into the mix and I think I now have a 90.75. That's way too close for me. And with less than 4 weeks left we have 2 more exams (one more lecture exam and one more lab practical), so that's a lot of learning to do in a short time. The thing is for how well I know that lecture and lab material my score should easily be about 95 now, not 90. Instead of having plenty of breating room for the final, I have none.

 

 

 

******************************

Here's another example of the type of True/False questions she asks (but changed to a subject most people are more familiar with).

 

True or False

1) Newton's second law of motion states that the acceleration an object experiences is proportional to the net force applied to the object.

 

So is that true or false?

[Biochemist]

I always loved the absurd test....My Organic II professor gave a final that had a class average of 17 out of 150.... Either you can say it was a poor test or poor teaching, but if that many people score that poorly on your exam, something is up. ;)

Organic was my most unusual class as well. It was lower division, a sophomore class, and it typically started with about 100 students. Usually less than 40 finished. The median on the first midterm (25% of the grade) was usually under 40%. Fully a fifth of the class got single digit grades. They all dropped it. Some folks were in their fourth attempt when I took it.

 

In biochem, my professor actually posted a sample problem answer the evening before a mid term. He posted the wrong answer. He put the exact same problem on the test. Only two of us had the nerve to put the correct answer on the test, because we were telling him his posted answer was incorrect.

 

All but two of us lost 30% of the exam off the top. The professor never acknowledged he posted an incorrect answer.

 

Go figure.

[zadojla]

My contribution to this topic is the Statistics professor I had in graduate school. In grad school, you had to maintain a B average, and any grade of D was automatically converted to F. He graded on a bell curve, regardless of test scores, so there were 10% A, 20% B, 40% C, 20% D, 10% F. He was one of the reasons I don't have an advanced degree.

[TeleMad]

Professors can be quite different.

 

I remember back in chem I there was an unfair question on the first test. It was in the section covering naming compounds given their formulas and writing formulas given their names. The name was mercuric "something" and students could only guess at what the correct formula should be because we were not supposed to know the difference between mercurous and mercuric. After I left class I e-mailed the professor stating that the chart he specified for us to learn for oxidation numbers did not contain mercury, so how could we know if the ous-ic break down was +1/+2 as in cuprous/cupric, or +2/+3 as in ferrous/ferric, or +2/+4 as in stannous/stannic, or some other combination, such as gold's +1/+3. When the tests were handed back I noticed that he dropped that question from consideration. THAT IS BEING FAIR AND ADULT ABOUT THINGS!

 

But this biology professor is quite different. Any statement that she can interpret in the slighest way as being a challenge to her methods or knowledge is met with scorn and/or additional work. In other words, one doesn't dare complain about a question or action of hers being unfair or unreasonable.

 

PS: And I'm not the only one in the class who thinks this. She was out last week (an out-of-state conference) so she left us an assignment to work on and had the chem professor open the door, computer closet, and lock up after class. Three of us were discussing the bio profs last test and we all agreed on how it was unreasonable. Unfortunately, the chem professor, who is her chum and decided to check in on the class to see what we were doing, walked in on part of the discussion. If he heard some of the negative comments we made about this particular biology professor and word gets back to her.. then I can probably kiss an A goodbye no matter what in A&P II, and maybe even any other bio classes I still have to take under her.

[bumab]

I had an O. Chem III class where the prof. had to curve the final grades so a 40% in the class (including lab section) was an A... You could get a 22% overall and get a C. Everytime you took a test it was like getting beat with a stick...