BIOL 212 SI, Molly

Dr. Coffman and Dr. Peterson

EXAM 5 REVIEW KEY

4/30/15

1.)The partial pressures of the gases in the atmosphere are:

  1. 21% Oxygen
  2. 78% Nitrogen
  3. <1% other components

2.)If the partial pressure of oxygen is 160 mmHg right now, at what elevation are you at?

160 mmHg (O2) = .21 (% O2) x X mmHg (atmosphere)

X = 760 mmHg = sea level

3.)Say you moved to a different location and the partial pressure of oxygen is now 40 mmHg. Did you go up in elevation (like climbing a mountain) or did you go down in elevation (like going into a valley)?

Up in elevation.

4.)What is the atmospheric pressure from problem 3?

Same problem as #2….. 40 mmHg = .21 x X mmHg

X = 190 mmHg

5.)Which of the following is false?

  1. A hiker from Iowa is in the Appalachian Mountains. He gets “altitude sickness” due to an insufficient partial pressure of oxygen in his lungs.
  2. As a diver dives into the ocean, she feels intense pressure exerted on her body.
  3. As the altitude increases, the partial pressures of the atmosphere decrease. In other words, they are inverse of each other.
  4. As the partial pressures of the gases change, the composition of the gases also have to change to compensate for the lost or gained pressure.

6.)Given Fick’s Law of Diffusion

Rate of diffusion = K x A x (P2-P1/D)

What will happen to the rate of diffusion for each of the following?

a)The thickness of the lungs increased by 1 µm. decrease

b)The difference between the partial pressures of oxygen increased. increase

c)The alveolar surface area doubled in size. increase

d)A lack of surfactant caused a third of the alveoli to collapse. decrease

7.)How does countercurrent gas exchange (like in fish) work? How is it so efficient?

The water goes in the opposite direction of the blood flow. It’s efficient because the hemoglobin can pick up one last oxygen molecule before leaving the gills.

8.)Binding of oxygen to hemoglobin is:

  1. Covalent and reversible
  2. Noncovalent and reversible
  3. Covalent and irreversible
  4. Noncovalent and irreversible

9.)Describe cooperative binding. What shape is the graph?

Cooperative binding is when oxygen can be sent to both resting and exercising tissues equally, but at the same time, exercise requires more molecules of oxygen. It is an “S” shaped curve on the graph.

10.)Would a pregnant mother want her oxygen or the baby’s oxygen to have a higher affinity for hemoglobin? Why is this so?

The baby’s oxygen needs to have a higher affinity because it needs the oxygen to grow and if the mother is holding onto the oxygen, then the baby will never get any.

11.)How does carbon dioxide travel through the blood? What does carbon dioxide do to the pH of your blood?

As bicarbonate in your blood plasma. Carbon dioxide makes the blood more acidic.

12.)Sketch a diagram of the circulation for each of the following types of circulations. Be able to describe if it is efficient or not.

  1. Single circulation (fish)

See Dr. Coffman’s slides from Thursday, April 23rd for a good diagram of all three circulations.

  1. Double Circulation (mammals)
  1. Intermediate Circulation (amphibians)

13.)Why would a puncture wound to the chest cavity, but not the lungs themselves, result in a collapsed lung?

Because the partial pressures in the body would be offset due to the partial pressure outside the body, resulting in the lung collapsing.

14.) What is chromatin remodeling?

It’s when the DNA releases from the proteins, before transcription, and alters the shape of the chromatin.

15.)Describe the structure of chromatin.

Chromatin consists of nucleosomes that are strands of DNA which are wrapped twice around eight histone proteins. The histone proteins are bound together, which condense the structure.

16.) Histone acetyl transferases are involved in chromatin alteration by decondensingthe chromatin. In reverse, histone deacetylases allow chromatin condensation.

17.)Which of the following about epigenetic inheritance is false?

  1. It’s changes in gene expression that are not due to differences in gene sequence.
  2. Daughter cells do not inherit epigenetic modifications.
  3. Epigenetic modifications are due to modifications of the chromatin.
  4. Epigenetic modifications contain information that influence whether a particular gene is expressed.

18.)Define:

  1. Gametogenesis – the formation of gametes
  1. Spermatogenesis – the formation of sperm
  1. Oogenesis – the formation of eggs

19.)Describe how a mature sperm is formed.

Spermatogonia primary spermatocytes  secondary spermatocytes (2)  spermatids (4)  sperm (4)

20.) Describe how a mature egg is formed.

Oogonia primary oocytes 1st polar body + secondary oocyte  2nd polar body + ootid egg (ovum)

21.) When does the oocyte nucleus complete meiosis II?

  1. After it is done maturing.
  2. Before the mature ovum is produced.
  3. Once the sperm and oocyte fuse.
  4. Two days after the sperm and oocyte fuse.

22.)What is the purpose of the placenta?

To provide the fetus with gases and nutrients and waste extraction.

23.) For land plants, the diploid phase of the life cycle is the sporophyte and the haploid phase of the life cycle is the gametophyte. The changing between these phases is called alternation of generations.

24.)What is pollination? Fertilization?

Pollination: the transfer of pollen grains from an anther to a stigma

Fertilization: when a sperm and an egg unite to form a diploid zygote

25.)In angiosperms, double fertilization is when two sperm combine with two polar bodies to form a 3n cell called the endosperm. What is the primary purpose of the endosperm? What is it similar to in mammals?

The endosperm provides nutrients to the embryo. It is similar to a mammalian placenta.

26.) The three parts of a mature seed are:

  1. Embryo
  2. Endosperm
  3. Seed coat