<p>Ha ok. Thats a weird system.</p>
<p>Approximately twenty days remaining before the exam.</p>
<p>Am I the only one who’s freaking out?</p>
<p>I’ve barely started studying, nor do I ever have the motivation to do so :/</p>
<p>^Don’t worry, you’re not the only one. (the no motivation part, not the freaking out part)</p>
<p>Haha, I go through cycles of freaking out then being apathetic. Through it all, I pretty much haven’t started studying yet.</p>
<p>I’m going to die…</p>
<p>It’s Senior year… motivation has died out. :|</p>
<p>I’ll post a few Barron’s questions, sorry if these have already been posted:</p>
<p>All of the following are true of white blood cells EXCEPT:</p>
<p>A. They are also called leukocytes
B. Examples are neutrophils and thrombocytes
C. Lymphocytes are of two major varieties: B type and T type
D. T lymphocytes engage in cell-mediated immunity
E. B lymphocytes are involved with humoral immunity</p>
<p>Which is NOT a part of the lymphatic system?</p>
<p>A. spleen
B. liver
C. tonsils
D. adenoids
E. lymph nodes</p>
<p>Refer to the list below of primary germ layers.
(A) Ectoderm
(B) Endoderm
(C) Mesoderm</p>
<ol>
<li>Gives rise to the lining of the digestive tract</li>
<li>Gives rise to the brain and eye</li>
<li>Gives rise to the blood</li>
<li>Gives rise to the bone</li>
</ol>
<p>@alittlemonster:</p>
<p>(B) Thrombocytes assist in blood clotting, but are not related to white blood cells.</p>
<p>(B) The liver is part of the digestive system, not lymphatic.</p>
<p>And i think (B) endoderm? Since the endoderm is the inner-most tissue layer and those are all kind of like internal organs? haha not positive on that one.</p>
<p>New Question…</p>
<p>The body regulates respiration rate based on blood pH and the concentration of</p>
<p>(A) CO2 in the blood
(B) O2 in the blood
(C) CO2 in alveolar sacs
(D) O2 in the brain
(E) lactic acid in the muscles</p>
<p>^I think that one is A. The medulla controls respiration from the pH of the blood. CO2 forms carbonic acid and so the lower the pH the higher the respiration rate should be.</p>
<p>^The endoderm question is in 4 parts. You are correct about it being innermost, so the answers would be:</p>
<ol>
<li>B (endoderm)</li>
<li>A (ectoderm)</li>
<li>C (mesoderm)</li>
<li>C (mesoderm)</li>
</ol>
<p>Which of the following causes stomates to close?</p>
<p>A. stimulation of the blue light sensor in the guard cells
B. active transport of H+ out of the guard cells into the surrounding cells
C. depletion of CO2 within the air spaces of the leaf
D. increase in sunlight
E. increase in abscisic acid in the guard cells</p>
<p>To observe the process of mitosis in plant roots, a student should examine the plant’s</p>
<p>A. root cap
B. zone of maturation
C. meristem tissue
D. pericycle
E. endodermis</p>
<p>All of the following evolved in plants in response to water shortage EXCEPT</p>
<p>A. mychorrizae
B. CAM metabolism
C. Kranz anatomy
D. cutin
E. large surface area of leaves to absorb sunlight</p>
<p>The primary function of the cortex in a plant stem is</p>
<p>A. storage
B. transport
C. photosynthesis
D. absorption
E. to maintain proper water potential</p>
<p>I’m guessing:</p>
<ol>
<li>A</li>
<li>C</li>
<li>A?</li>
<li>A</li>
</ol>
<p>Edit: I’m changing my answer to the first question to… maybe E? Because stimulation of light should cause the stomate to open, not close, and same with the depletion of CO2 and the transport of H+ out of the guard cells…</p>
<p>1 is indeed E. According to Barron’s, lack of water, high temperatures and an increase in abscisic acid cause stomates to close. Things that cause stomates to open are depletion of CO2, an influx of potassium ions into the guard cells and the stimulation of the blue-light sensor in the guard cells. Also, stomate opening correlates with active transport of H+ out of guard cells.</p>
<p>2 is C.</p>
<p>3 is E, I originally guessed A too. Again, Barron’s words: All choices describe responses to water shortage except E. A large surface area of leaf to maximize the amount of sunlight absorbed would also increase water loss. Leaves in a tropical rain forest, where the environment is very humid, are typically broad. The needles on a conifer evolved to minimize water loss. Conifers are found in cold, dry northern regions. </p>
<p>4 is A. The cortex stores starch and other various things.</p>
<p>^haha, I never knew mychorrizae can also increase the capacity for water absorption.</p>
<p>Next question…</p>
<p>From Cliffnotes: The lac operon in E. coli is involved in </p>
<p>A. regulating the expression of a gene
B. regulating the translation of mRNA
C. controlling the formation of ribosomes
D. controlling DNA replication
E. preventing the transfer of F plasmid</p>
<p>A, but I have trouble explaining why. I think that when lactose is not present, it cannot bind to the promoter site to unwind the DNA strand to allow it to be transcribed?</p>
<p>Can someone explain interstitial fluid and extracellular fluid? I get the processes, and I can memorize it and spit it back out, but I don’t get how there is fluid in between cells or how the red blood cells in the capillaries carry stuff to be absorbed by the cells next to the capillaries.</p>
<p>^^ I thought it was D.</p>
<p>EDIT: never mind, I thought it said EXCEPT and D just grabbed my attention.</p>
<p>It’s A</p>
<p>It’s A. The lac operon activates when there is a lack of glucose in the cell. Not until then though, no matter how much lactose there is.</p>
<p>Yep it’s A. The official explanation: “Operons are DNA segments that include a promoter region, an operator region, and a series of structural genes. Together with a regulatory gene lying outside the operon, the three parts of an operon work collectively to control transcription, which results in a regulation of gene expression.”</p>
<p>The questions below refer to parts of the human digestive system listed below:</p>
<p>(A) Mouth
(B) Esophagus
(C) Stomach
(D) Small intestine
(E) Large intestine</p>
<ol>
<li>Where does the digestion of fats occur?</li>
<li>Where does the reabsorption of water used during digestion occur?</li>
<li>In which structure is there no digestion?</li>
<li>In which structure is digestion completed?</li>
<li>Which structure contains the microvilli?</li>
</ol>
<hr>
<ol>
<li><p>The lacteal is found in the _<strong><em>, and is involved with _</em></strong>.
(A) stomach; the release of hormones
(B) duodenum; the hydrolysis of lipids
(C) small intestine; the absorption of fatty acids
(D) colon; the reabsorption of water
(E) liver; production of hydrolytic enzymes</p></li>
<li><p>The pacemaker of the heart is
(A) the bundle of His
(B) the atrioventricular node
(C) the diastolic node
(D) the semilunar node
(E) sinoatrial node</p></li>
</ol>
<ol>
<li>D</li>
<li>E</li>
<li>B </li>
<li>E</li>
<li>D</li>
<li>C</li>
<li>E</li>
</ol>
<ol>
<li>D</li>
<li>E</li>
<li>E</li>
<li>D</li>
<li>D</li>
<li>C</li>
<li>E</li>
</ol>