<p>Germ layers:</p>
<p>Endoderm: The innermost layer. It will form the lungs, liver, digestive system etc.
Mesoderm: Middle layer. Some animals have a mesoglea instead. It will form blood and bone
Ectoderm: The outermost layer. This will form the skin, and the nervous system. </p>
<p>Describe the process of Oogenesis.</p>
<p>Does anybody have any old tests that I could get for practice?</p>
<p>no. 10char</p>
<p>B cells: B cells are cells that are built and made in the bone. Once a pathogen arrives in the bloodstream, there are many things that attempt to destroy it. One of which is the b cells. The b cells have receptors on their surface, and if an antigen attaches to the receptor on the B cell, it triggers the b cell to divide rapidly. Some of the cells turn into plasma cells, which produce antibodies that clump the antigens together. Whereas other b cells divide into memory b cells which help the body fight an antigen that it has already been exposed to. </p>
<p>T cells: These are lymphocytes. They distinguish between self and non self by using the MHC markers on the plasma membrane. When a T cell finds a nonself cell it does the following. Firstly, it produces cytoxic T cells aka killer T cells which kill of the non self cells by puncturing them causing them to lyse. Secondly, it produces helper T cells which stimulate both the B cells and the killer T cells.</p>
<p>1a1, there’s a couple on [Free</a> AP Bio Practice Tests](<a href=“http://ap.testfrenzy.com/biology.html]Free”>Free AP Bio Practice Tests). They have the answers at the end too.</p>
<p>does anyone know how the ap bio exam is 150 pts?</p>
<p>^ 100<em>.9=90. 40</em>1.5=60. 90+60=150.</p>
<p>does anyone know where i can find the 1999 or 2002 version of the ap bio exam without buying it?</p>
<p>should we learn about chi squares? they havent been on the exam in a long time…</p>
<p>hey i have a quick question for you guys.
in photosynthesis where do photophosphorylation and the calvin cycle occur?</p>
<p>calvin cycle is in the stroma</p>
<p>frenchhorngirl, 2002 is here (password=APPLE) but 1999 doesn’t seem to work [Free</a> AP Bio Practice Tests](<a href=“http://ap.testfrenzy.com/biology.html]Free”>Free AP Bio Practice Tests)</p>
<p>hey thanks, yeah i tried it but it doesn’t work for me either. bleh</p>
<p>photophosphorylation is in the thyloids (spell?)</p>
<p>^ thylakoid</p>
<p>can somebody define autosomal recessive</p>
<p>@bicyclekick 
Thanks. I fail at spelling biology terms.</p>
<p>[Edit] Autosomal recessive is just the normal kind of recessive. Say there are two alleles for green fur and red fur. Green’s dominant (G), red’s recessive (g). Suppose Gg cross with Gg: they produce 25% GG, 50% Gg, 25% gg. </p>
<p>I’m sick of studying; good bye bio for tonight. Here’s a summary of AP biology under 100 words:
Polarity in water is the answer. Little molecules stick together to form bigger molecules. Light cause electrons to jump around in leaves. Bacteria just split themselves in half, but most other organisms can’t. Protists are everything that doesn’t belong anywhere else. Plants can stand somewhere and make food for themselves. Stomach produces acid. When muscles move, they need energy. Rainforest is warmer than tundra.</p>
<p>what is a signal transduction pathway?</p>
<p>i’m trying to get a hold of the 2001/2002 tests, but the site you’ve posted doesn’t work. it says bandwidth exceeded-error. so can anyone please e-mail me either the 2001/2002 ap bio exam…i’ll trade you a 1999 one.
=/ in desperate help</p>
<p>^ the 2002 test opens for me…but the answers don’t for some reason</p>