week one quiz

Question 1

the same kind of blood flows through five identical blood vessels. each vessel has the same radius, but different flow rates. you measure the pressure at the beginning and ending of each vessel

Vessel Staring pressure Ending pressure
1 220 140
2 210 160
3 200 110
4 170 140
5 150 80
which blood vessel has the lowest flow rate?

Answer 1

4

Question 2

you are studying blood flow in the aorta of five different animals. the characteristics of the blood and the vessels are the same in all animals. however, the flow rate was different. you measure the blood flow at the beginning and end of each aorta
Vessel Staring pressure Ending pressure
Red panda 210 130
Weasel 230 140
Otter 270 160
Wolverine 170 140
Capybara 120 90
which animal has the greatest flow rate through their aorta?
a) red panda
b) capybara
c) wolverine
d) weasel
e) otter

Answer 2

e) otter

Question 3

If blood temperature rises too high (100 F), this is sensed by specialized neurons in the hypothalamus of the brain. They signal other nerve centers, which in turn send signals to the blood vessels of the skin. As these blood vessels dilate, more blood flows close to the body surface and excess heat radiates from the body. If this is not enough to cool the body back to normal (98.6 F), the brain activates sweating. Evaporation of sweat from the skin has a strong cooling effect, as we feel when we are sweaty and stand in front of a fan.

a) this is not describing a feedback loop
b) this is describing a negative feedback loop
c) this is describing a positive feedback loop

Answer 3

b) this is describing a negative feedback loop

Question 4

If blood temperature rises too high (100 F), this is sensed by specialized neurons in the hypothalamus of the brain. They signal other nerve centers, which in turn send signals to the blood vessels of the skin. As these blood vessels dilate, more blood flows close to the body surface and excess heat radiates from the body. If this is not enough to cool the body back to normal (98.6 F), the brain activates sweating. Evaporation of sweat from the skin has a strong cooling effect, as we feel when we are sweaty and stand in front of a fan.

In this example, the set-point would be

Answer 4

98.6

Question 5

as we have discussed the cell membrane is composed of a lipid bilayer. which part of the membrane is attracted to water?
a) phosphate heads because they are hydrophobic
b) fatty acid tails because they are hydrophilic
c) phosphate heads because they are hydrophilic
d) fatty acid tails because they are hydrophobic

Answer 5

c) phosphate heads because they are hydrophilic

Question 6

an enzyme generally works by-
a) increasing the pH value
b) increasing activation energy
c) decreasing activation energy
d) decreasing pH value

Answer 6

c) decreasing activation energy

Question 7

It is a nice, cool autumn morning and you decided to go for a short, easy 3-mile run before class. Your body temperature increases to ~38 C, what has happened to enzyme activity compared to the time just before your run.
a) increased due to increased core temperature
b) increased due to increased core temperature
c) decreased due to increased core temperature
d) decreased due to decreased core temperature

Answer 7

a) increased due to increased core temperature

Question 8

actin is an example of a/n-
a) microfilament
b) microtubules
c) intermediate filaments
d) organelle

Answer 8

a) microfilament

Question 9

a cell’s function is directly determined by-
a) pH of the cell
b) chemicals bound to the cell
c) temperature of the cell
d) contents of the cell

Answer 9

d) contents of the cell

Question 10

you discover a new molecule that has the following shape.
I=U=I
this molecule is
a) non-polar
b) polar

Answer 10

polar