<p>What are differences between Darwin's and Lamarck's theories on evolution?</p>
<p>THANKS! I was talking about metastasis, not epistasis. Sorry!</p>
<p>Some postzygotic barriers include the following:</p>
<p>a. Hybrid Sterility
b. Hybrid Inviability
c. Hybrid Breakdown</p>
<p>Darwin proposed natural selection as the mechanism for evolution. Some organisms happen to possess adaptations better suited to their environment and are more successful in reproducing and contributing their genes to the gene pool. Others do not and are less successful in reproduction.</p>
<p>Lamarck thought of inheritance of acquired characteristics. Let's say that I like to hit the weight room and train intensely to make my body more cut. Then, according to Lamarck, my kids should be very muscular. Well, it is true that if I keep pumping iron, then I'll get bigger. What isn't true is that my kids will have this.</p>
<p>Describe the carbon cycle.</p>
<h2>No, I very well meant "Epistasis;" its in context of heredity. I have an explanation right after it--very simple, I know.</h2>
<h2>You're mixing two prezygotic barriers, but i have them mentioned on page "2."</h2>
<p>Hm, the Carbon Cycle is quintessential in the building of organic molecules. You basically need to remember the cycle's 1. Resovoirs, 2.where it Assimilates, and 3.Releases.</p>
<p>So, Carbon is taken from atmospheric CO2, and fossil fuels. That's your resovoir.</p>
<p>Plants obviously use CO2 in photosynthesis (Calvin Cycle in the formation of glucose). Assimilation.</p>
<h2>Then Plants obviously release CO2 through respiration and decomposition. It's easier to remember that when burning wood, or some substance--CO2 is the byproduct.</h2>
<p>No one answered it yet, it isn't hard, but it still stands:</p>
<p>Describe the process of Transduction. Determine the difference between the Lytic and Lysogenic cycle of virus'.</p>
<p>Hm, is anybody taking the SAT II in biology May 7th? If you have taken it--any words of wisdom? What to go over? What to expect? The whole "Sh-bang" would be awesome.</p>
<p>Transduction is the process by which viruses reproduce. Lytic cycle involves virus implanting its genetic info into a cell and takes over cellular machinery to create copies of itself with viral proteins and genetic info packaged. The cell lyses afterwards and releases viruses elsewhere.</p>
<p>Lysogenic cycle has the viral genetic info incorporated into the cell DNA and it may be dormant for a while. The viral DNA gets copied along with cellular division. After dormancy, lysogenic reverts to lytic and the cycle continues.</p>
<p>Describe the major evolutionary trends in excretory systems through animal lineages.</p>
<p>Not really: Transduction is one of the three ways in which prokaryotes attain genetic variation (conjugation and transformation being the other two.) You're right that it does involve Virus', but the main concern is the virus. When in a lysogenic cycle (using a retrovirus to make DNA, incorporating itself into the DNA), the Virus takes, when replicating in the host cell, a segment of the Bacteria's DNA as well. Eventually, the "daughter viri" if you will, get segments of the prokaryote's DNA. Later, when the cell lysis' the new virus' go to different bacterial cells, but not only do they incorporate their own genetic material, but the genetic material from the preceding bacteria.</p>
<hr>
<p>"Describe the major evolutionary trends in excretory systems through animal lineages."</p>
<p>Hm, well without getting into detail (someone else can elucidate, i think I'm going to get Carpel tunnel in my wrist from all the typing)...in the excretory system evolution has occurred in: the contractile vacuoles, Flame cells (particulary in flat worms), the Nephridia, something with an "M"....maliphian? Malpighian tubules, and the kidney's.</p>
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<p>1.The___________ turns on when there is an inumerable amount of CO2 and a low ph.</p>
<p>2.Differentiate between an F plasmid and an R plasmid.</p>
<p>(simple).</p>
<p>Ah? okay?<br>
1.When your body is lacking oxygen (a lob of bicarbonate in the blood) as well as low ph (dangerous), the thalamus recieves the information and relays back to your cerebral cortex.
2.The F plasmid is exclusively involved in the formation of the pilus in between prokaryotes during conjugation (exchange of genetic information). The R plasmid on the other hand gives the prokaryote the ability to resist various antibiotics.</p>
<hr>
<p>Q: What are the difference between C3, C4, and CAM plants?</p>
<p>C3 plants are the most common plants that fix CO2 directly to RuBP.
C4 plants first fix CO2 to PEP then goes through several reactions that make PEP to pyruvate, oxaloacetate, malate, and then finally CO2 again down in the bundle sheath cells of the mesophyl. CAM plants only open stomata in the night and collect CO2 keeping it in malic acid form. In the day, stomata are closed and CO2 is converted from malic acid to go into the Calvin Cycle.</p>
<p>Describe the endocrine responses in positive and negative feedback mechanisms for blood glucose level control and menstrual cycle.</p>
<p>For blood glucose levels, hormones secreted from the pancreas insulin and glucagon are used. Insulin lowers blood-glucose levels, and glucagon raises.</p>
<p>What is interspecific competition?</p>
<p>Competition between several species for resources, as in several warbler species. :)</p>
<p>Where does ultrafiltration take place?
A) loop of Henle
B) glomerulus
C) Bowman's capsule
D) proximal convoluted tubule
E) None of the above</p>
<h2>glomerulus--involved at the nephron, which is involved in filtration of wastes in the kidney. The glomerulus is a capillary bed in the area. Excretory is something i need to go over; definately not my forte yet. Thanks.</h2>
<p>Q: Elucidate: Polyploidy, Balanced Polymorphism, Hybridization, and Adaptive Radiation in terms of Sympatric Speciation.</p>
<p>Aye Carumba, someone answer it. Ok, well--fine.</p>
<h2>Well, it's evident that sympatric speciation involves the formation of a new species WITHOUT geographic barriers or pre or postzygotic barriers. So, in terms of polyploidy: organism, particulary plants experience non disjunction of a homologous pair of chromosomes in anapahase I, eventually undergoing meiosis II, one of the haploid cells that remain possess the the polyploid (more than the homolgous pair). So, if the parent plants give rise to polyploid progeny--they automatically have created a new species, by allowing to express multiple traits, one trait, specific traits, or a mutation allowing a new trait. OK! So, then in Hybridization--two species that are seperated by a geographic barrier mate along a hybrid zone, new offsping--yatti yatta yatta. The paradigm of Adaptive radiation are the finches of gallapagos; coming from a common ancestor. They all changed due to particular environmental conditions--beak size that is. FINALLY! Balanced polymorphism allows for multiple phenotypes to be expressed in a particular species (yes, species; we're still micro here). That includes heterozygote advantage, hybrid vigor, and minority advantage.</h2>
<p>Q:
1.Describe the four levels of protein structure.
2.How can they be degraded?</p>
<p>1.
Four general levels of protein structure</p>
<p>a. Primary structure- determines the amino acid sequence, which are bonded together by peptide bonds
b. Secondary Structure- determines the way in which the amino acid chains twist or fold to form either an alpha helix or a beta pleated sheet shape.
c. Tertiary structure- provides ADDITIONAL folding/twisting of the amino acids, due to their partial amphipathic nature or the hydrogren a/o disulfide bonds that form.
d. Quaternary structure- orgranizes and bonds together amino acid chains (polypeptides) into a final shape, in the case that there are more than one (i.e. hemoglobin- there are 4 polypeptides). Salt bridges, disulfide bonds, hydrogen bonds all contribute to the final shape of the protein. This level of structure is also referred to as the organization and arrangement of multiple subunits. Quaternary structure is not always found- usually in the more complex proteins.</p>
<p>2.
somebody please answer this..</p>
<p>Well, proteins can become denatured and lose their three-dimensional shape through temperature and pH differences (e.g. too high of a temperature or too low of a pH).</p>
<p>How does cytokinesis occur in plants?</p>
<h2>Proteins are easily degrade by an influx of a ph and temperature. Look at pepsin for example in the stomach. It can only function at low pH's; if subjected to higher pH concentrations it would not only be able to function, but also corrode.</h2>
<p>Q:
1.RNA polmerase attaches to the promoter region known as the_<strong><em>in transcription.
2.This splicesome, called</em></strong>____cleaves introns, and connects exons together. (this is after the GTP, and Poly A tail are added).</p>
<p>To fabrizio, in cytokinesis for plants, a regular cleavage furrow does not form as in animal cells. Instead a cell wall grows in between the two cells. This is called something that starts with a T. Someone wanna help me out?</p>
<h2>Nah, the name your looking for pentasa is "cell plate." That's all it is. Then in animals yes, it's most definately a cleavage furrow.</h2>
<p>ok, well since no one wants to answer my question...
1.TATA box</p>
<h2>2.snRPs</h2>
<p>Question(s):
1.______is a plant hormone that stimulates flowering in plants.
2. What is the difference between auxin and giberillin?</p>
<p>I'm gonna go with florigen, or something like that, for the flowering one. Is that right?</p>
<p>Auxin promotes growth in plants, used in phototropism. Gibberelins are used to revive dead plant cells or something, also involved with growth i think. I'm a little fuzzy but I think that should be good enough for now.</p>
<p>Q: Trace the central dogma of molecular biology.</p>
<p>Yeah, it's florigen. Ethylene ripens fruit.</p>
<h2>Honestly, too me, gibberillin and auxin sound very much the same. When taking tests, Friends of mine constantly can't tell the difference due to the fact that they're both involved in elongation. Gibberillins however are involved in infant plants primarily--elongation and stimulates meristimatic growth (rapid cell division.) Auxin, you're right is elongation as a result of phototropism. Also called indoleacetic acid. It's a good thing i reviewed that today. phew.</h2>
<p>Simply, central dogma of molecular biology is:
1.DNA replication (semi conservative)
2.Transcription
3.RNA processing</p>
<h2>4.Translation</h2>
<p>Q:
1.Who were Oparin and Handane?
2.What was there thesis?
3.Who validified their thesis?</p>