<p>Hi everyone,</p>
<p>I have a few questions regarding the Bio SAT II that were left unsettled in past threads that I hope can be put to rest here.</p>
<ol>
<li><p>What is the endosymbiotic theory proven by? Is it bacteria and mitochondria having the same lipid layer, or them having similar RNA?</p></li>
<li><p>In higher plants, meiosis produces what? Is it pollen grains, spores, seeds, or gametes? I'm not sure if these are all choices, but they were all discussed.</p></li>
<li><p>Which structure of the ear determines pitch? Is it the basilar membrane, or is it the tympanic membrane?</p></li>
</ol>
<p>Thanks!!</p>
<ol>
<li>I think you’re confused by the phospholipid bilayer proof of endosymbiosis for mitchondria and plastids. Mitochondria and chloroplasts have TWO phospholipid bilayers - logically, this would mean that there’s one layer from its days as a prokaryote, and another as a vacuole from when it entered the prokaryote/eukaryote (we don’t know when the endosymbiosis happened). There’s also some secondary endosymbiosis theory for plastids and mitochondria that have four bilayers, but you don’t have to know that. The theory for DNA and RNA is that plastids and mitochondria have their own RNA and DNA and (I think) proteins. The DNA replicates separately during cell division.</li>
<li>In higher plants, meiosis produces… well it depends. In gametophyte generation it produces pollen grains and eggs which, through flowers in the angiosperms and I think cones in gymnosperms, develop into zygotes and starts the sporophyte generation. In the sporophyte generation it generates the cell that becomes the gametophyte - I don’t even know the name of it; we never learned it and it wasn’t in my review book.</li>
<li>I’ve never seen a question on the ear in a practice bio SAT II test.</li>
</ol>
<p>djumper is correct…
Ear questions have been asked at least three times.</p>
<p>The question he’s speaking of was something to the effect of “Which of the following part of the ear detects pitch?”
Choices include tympanic membrane
basilar membrane
cochlea
and two other choices I can’t remember</p>
<p>Cases were made in past threads for both tympanic and basilar… Can anyone definitely answer it?</p>
<p>For questions 1 and 2, I would also like to know the correct answers. I remember reading them in past Bio SAT threads as well…</p>
<p>Anyone?</p>
<p>Anyone else? I really need to know the answers to these.</p>
<p>In regards to the ear:</p>
<p>a vibrating object sends a wave of pressure fluctuation through the atmosphere. We hear different sounds from different vibrating objects because of variations in the sound wave frequency. A higher wave frequency simply means that the air pressure fluctuation switches back and forth more quickly. We hear this as a higher pitch. When there are fewer fluctuations in a period of time, the pitch is lower. The level of air pressure in each fluctuation, the wave’s amplitude, determines how loud the sound is.
This tiny flap of skin acts just like the diaphragm in a microphone. The compressions and rarefactions of sound waves push the drum back and forth. Higher-pitch sound waves move the drum more rapidly, and louder sound moves the drum a greater distance.</p>
<p>The eardrum is the entire sensory element in your ear … the rest of the ear serves only to pass along the information gathered at the eardrum</p>
<p>[Discovery</a> Health “How Hearing Works”](<a href=“How Hearing Works | HowStuffWorks”>How Hearing Works | HowStuffWorks)</p>
<p>So I believe it is tympanic membrane since it varies by pitch</p>
<p>For endosymbiotic:</p>
<p>Mitochondria and chloroplasts have striking similarities to bacteria cells. They have their own DNA, which is separate from the DNA found in the nucleus of the cell. And both organelles use their DNA to produce many proteins and enzymes required for their function. A double membrane surrounds both mitochondria and chloroplasts, further evidence that each was ingested by a primitive host. The two organelles also reproduce like bacteria, replicating their own DNA and directing their own division
[The</a> Evolution of the Cell](<a href=“http://learn.genetics.utah.edu/content/begin/cells/organelles/]The”>http://learn.genetics.utah.edu/content/begin/cells/organelles/)</p>
<p>As for meiosis, I’m not too sure about. It should be in your review book though</p>
<p>Two last questions I really need answered in the next few hours-</p>
<p>Which is not a mutation - chromosome aberration, insertion of DNA nucleotide into DNA, deletion of DNA nucleotide into DNA, deletion of triplet in DNA, change in post-transcription DNA?</p>
<p>Which is least important in classifying organisms- presence of a body cavity, symmetry?</p>
<p>Thanks!!</p>
<p>A change in post-transcription DNA is not a mutation. Keep in mind that mutations occur during DNA replication or the transcription process, wherein DNA is modified. Even though a change in the nucleotide base sequence of a RNA can occur, the change will not result in a mutation of genetic material.</p>
<p>The second question seems kind of ambiguous since both characteristics are used to classify organisms. Animals can be classified based on radial or bilateral symmetry and whether they have a coelom (body cavity).</p>