<p>Who would like to start with the revision?</p>
<p>is it too late to start now? =P</p>
<p>what revision?</p>
<p>I mean that everyone here writes a note that he knows very well in the biology</p>
<p>That may help many other people not just me</p>
<p>ok
here's some random stuff i found ove rthe past few days (keep inmind i haven't done american high school, and hence stuff that's new to me might be commonplace with others)</p>
<p>a germ cell is, yes a sex cell, and hence has 23 chromosomes</p>
<p>Monera Protista Plantae Fungi Animalia (correct order of evolution)</p>
<p>DNA segments are all equally polar</p>
<p>Hershey-Chase exp proved that viruses' DNA is the key to their replication</p>
<p>Commensalism is a kind of symbiotic relationship in which one organism benefits while the other is relatively unaffected.. e.g. between a bird and the tree it lives in</p>
<p>transduction is the introduction of foreign DNA into another cell via a viral vector... it is how viruses infect their DNA into hosts</p>
<p>Disruptive/Diverging Selection:
when evolution takes two extreme paths, e.g. moths are either bright or black, no intermediate</p>
<p>Stabilizing Selection:
genetic diversity decreases, as population focuses on a particular trait value.. i guess this's sorta like the giraffe's neck</p>
<p>the example i read for this was that fetuses nowadays outgrow the reproductive tracts of their mothers because they're focussing on being bigger or something =/ check wiki though, i'm too sleepy to understand it =S</p>
<p>oxygen is produced in teh LIGHT STAge of photosynthesis.. glucose in the DARK STAGE</p>
<p>Glycolysis in respiration occurs in cytoplasm (always good to remember)</p>
<p>a sex-linked recessive gene MAY show up on a female offspring if the father has the Xchromosome causing it and the mother is a carrier...</p>
<p>disaccharides, unlike monosaccharides, have a general formula [Cn H 2n-2 O n-1]</p>
<p>exponential growth is the unlimited growth of a population</p>
<p>egg-yolk is a single cell (yeap)</p>
<p>endotherms are what we as children called "warm-blooded animals"</p>
<p>only birds and mammals have 2 chambered hearts... amphibians and reptiles have 3 chambers,, fish have two(i think.. look into fish though)</p>
<p>nondisjunction (failure of a chromosome pair to separate properly during cell division) of the egg causes Down's syndrome</p>
<p>in one meiosis, 4 sperms cells are formed.... but only 1 egg is formed</p>
<p>man and whale apparently had a common ancestor, the skeleton of which was found in Pakistan a few decades back... this was in barron's 12th edition (i didn't buy the 13th edition,, God knows why)</p>
<p>myosin and actin cause contraction of sarcomere in muscles to cause muscular contractions</p>
<p>parathyroid gland controls amount of calcium in the blood stream</p>
<p>erm..that's all for now</p>
<p>pray for me people =P it's all we've got left..prayer ...</p>
<p>SAT II Biology Important Notes</p>
<p> Sexually reproducing organisms show greater variation than asexually reproducing ones because of recombination of alleles.
Isolation doesnt contribute to variation in a population
Oxygen released by plants comes from Water
Blue-jay is not a mammal
Floods is considered density-independent factor.
Vitamins are essential for normal cell function. They are important because they enable enzymes to function normally
Tendons connect bone to muscle
Ligaments connect bone to bone
Food chains never consist of more than 4 or 5 trophic levels. The reason for this is that energy is lost along the food chain.
Law of dominance states that when two organisms homozygous (pure) for two opposing traits are crossed; the offspring will be hybrid (carry two different alleles) but will exhibit only the dominant trait.
Law of Segregation states that during the formation of gametes, the two traits carried by each parent separate.
Monohybrid Cross is a cross between two organism that are each hybrid for a single trait, such as Tt x Tt (T = tall; t = dwarf)
Law of independent assortment applies when a cross is carried out between individuals that are hybrid for two traits on separate chromosomes.
Incomplete dominance is characterized by blending.</p>
<p>
[quote]
only birds and mammals have 2 chambered hearts... amphibians and reptiles have 3 chambers,, fish have two(i think.. look into fish though)
[/quote]
</p>
<p>Birds and mammals have 4 chambered hearts.</p>
<p>Erm...</p>
<p>In the Protostomes, the mouth develops first, then the anus.
In the Deuterostomes, the anus comes first, and then the mouth.</p>
<p>:D</p>