<p>what structures,in order, does a single drop of blood come across when entering the heart and lungs?</p>
<p>From the vena-cava, it goes into the right atrium, through the tricuspid valve, into the right ventricle, through the pulmonary valve, into the pulmonary artery, through the lungs where it is oxygenated, into the pulmonary vein, to the left atrium, through the mitral valve, into the left ventricle, through the aortic valve, into the aorta.</p>
<p>?
I don’t understand that question.
superior vena cava
right atrium
tricuspid valve
right ventricle
pulmonary semi lunar valve
pulmonary arteries
pulmonary arterioles
pulmonary capillaries
lungs alveoli
pulmonary venules
pulmonary veins
left atrium?</p>
<p>is that what you mean</p>
<p>yes, that question was my teacher’s way of making sure we know the order of blood flow, not just the names of the structures.</p>
<p>Name all the selections in evolution, and briefly explain them.</p>
<p>Stabilizing selection - the middle frequency is selected for reducing the frequencies of those on either side; example of gray bugs blending in with a gray rock, causing black and white ones to fade out</p>
<p>Directional selection - one extreme is selected for; example of disease-resistant viruses</p>
<p>Disruptive selection - both extremes are selected for; Darwin’s finches being able to eat small or large nuts develop small or large beaks</p>
<p>Sexual selection - females choosing males based on secondary sex characteristics and males fighting each other over mates causes advantageous secondary sex characteristics to be selected for; peacock feathers</p>
<p>Kin selection - reproductive strategies increase the fitness of one’s offspring</p>
<p>Kin selection is ecology, but whatever.</p>
<p>Explain the nitrogen cycle.</p>
<p>The nitrogen cycle is composed of two parts: nitrogen fixation and denitrification.</p>
<pre><code> In nitrogen fixation bacteria in the soil convert nitrogen gas into ammonia. Then other bacterias in the soil convert this ammonia to nitrates and nitrites. Now that the nitrogen is in this form, the producers can take it up and use the nitrates to produce proteins. Then these producers are eaten by the consumers which allows the consumers to also use the nitrogen complexes thus allowing them to create proteins as well.
When these consumers die and decompose, which is known as denitrification, the nitrate is then reabsorbed by the soil as ammonia. Thus restarting the cycle.
</code></pre>
<p>Question: Explain the life cycle of bryophytes.</p>
<p>Denitrification is done by denitifying bacteria that convert nitrate back to atmospheric nitrogen. Ammonifcation is done by detrivorous bacteria that convert organic compounds back to ammonia. Plenty of ammonia is excreted in urine, urea, and uric acid.</p>
<p>Bryophytes are the plants that experience alternation of generations, correct? If so, the sporophyte generation builds on top of the previous gametophyte generation. The sporophyte generation reproduces by meiosis whereas the gametophyte generation reproduces by mitosis.</p>
<p>EDIT: Oh, and they are non-vascular.</p>
<p>Describe the six plant hormones.</p>
<ol>
<li>auxins: growth hormone. It grows length wise.</li>
<li>cytokenins: growth hormone. Opposite effect of auxins, stops the apical dominance</li>
<li>gibberlinns: fruit development?</li>
<li>Ethylene: ripening hormone</li>
<li>Absisic Acid: growth inhibitor.</li>
<li>???</li>
</ol>
<p>Do you think this would be enough for frqs or should i review a little more?</p>
<p>Auxin functions in cell elongation. Cytokinins function in cell division. The ratio of the two hormones basically controls the effect of apical dominance.</p>
<p>Gibberellins (sp?) function in both elongation and division. They even spur germination in seeds. Absiscic Acid is primarily a growth inhibitor. Build-up of the hormone can also result in closing of the stomata in a drought. The ratio of the two hormones controls seed germination.</p>
<p>Brassinosteroids are a growth hormone, but I really don’t think they’re as important as the other three because they are relatively new. They are structurally similar to human hormones.</p>
<p>Ethylene can result in ripening, the triple-response, cell death, etc. The triple response is horizantal growth and can be activated if an object (such as a rock) is placing pressure on an underlying seed undergoing germination. Cell death is for structural cells such as tracheids or vessel elements that are dead at functional maturity, and the part of the cell that dies is its protoplast.</p>
<p>The more crap you throw on the wall with free response, the better the chance you have of it sticking.</p>
<p>Describe the different types of mutations that can occur.</p>
<p>Point mutation = one base is changed. This can either be a silent mutation (no phenotypic effect due to the wobble), missense (wrong amino acid coded for), or nonsense (stop codon prematurely called for).</p>
<p>Frameshift mutation = one base is inserted or deleted, causing the entire mRNA strand to shift based on the reading frame. This can either result in extensive missense or immediate nonsense. Phenotypically, frameshifts will almost always result in a screwed up protein, but rarely, it confers an evolutionary advantage or a new novel function.</p>
<p>Chromosomal mutation = large fragment of the chromosome is added/deleted/swapped/duplicated</p>
<p>Duplication = a section of the chromosome is duplicated and inserted. This causes a paralogous homology, conferring a greater evolutionary function since the two genes can mutate and take on distinct functions.</p>
<p>Inversion = during crossing over, a chromosomal segment is reattached in reverse order</p>
<p>Translocation = a fragment of a chromosome is deleted from one chromosome and attached to another; the Philadelphia chromosome involves a translocation of 9 and 16 (I think)</p>
<p>Aneuploidy = extra (trisomy) or missing (monosomy) chromosome; trisomy 21 causes Down’s syndrone</p>
<p>Nonsense- when a nucleotide is switched creating a codon that stops RNA. This results in a nonfunctional protein.</p>
<p>Missense- when a nucleotide is switched creating a RNA that will still code for what it was meant to.</p>
<p>Frame shift- when a nucleotide is added or deleting causing the sequence to move down or up one (or however many nucleotide were added)</p>
<p>Example: Ate The Cat (original) TET HEC AT (deleted) AIT ETH ECA T (added) </p>
<p>Nondisjuction: During meosis chromosomes may be deleted or two chromosomes may move to one gamete. (ploypoldy?) plants survive this, animals rarely do.</p>
<p>translocation: when part of a chromosomes moves to another chromosome. Example is part of chromosome 14 moving to 21 which may result in down syndrome.</p>
<p>Inversion: when part of a chromosomes is inverted 180 degrees. </p>
<p>I think i got a few points wrong.</p>
<p>anyway… NAME FIVE EVOLUTIONARY TRENDS IN HUMANS.</p>
<p>I honestly don’t remember reading anything about evolutionary changes in humans.</p>
<p>Would cephalization count? What about standing upright? Opposable thumbs?</p>
<p>For missense, I just want to add that the new condon could code for the same amino acid before mutation, or it could code for a complete different amino acid. </p>
<p>I have never heard of evolutionary trends in human… Maybe Flynn’s effect (increase in intelligence test scores)?</p>
<p>uh, yeah I don’t know any evolutionary changes in humans specifically, do you just mean chordates? If so:</p>
<p>-deuterostomes
-radial and indeterminate cleavages
-differenced in coelom formation
-anus developement from blastopore
-notochord</p>
<p>New questions, then. What is bottleneck effect and founder effect?</p>