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AQA BIOL2 Biology Unit 2 Exam - 26th May 2011

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I hope it doesn't have a "wtf" question like unit 4 biology did in january.

However this would be in true aqa style, we had a 15 mark question on Cow ****.

Reply 841

ksimmi25

Anyone know the answers to these?

How will the composition of the hepatic portal vein and hepatic vein differ?

How will the composition of the hepatic artery and hepatic vein differ?

Reply 842

jessplease

Original post by BeejTheone

Jessplease <3 How did i know you'd be here

loool well you know, doing what i do best :wink:

Reply 843

ScienceGeek3

Original post by ksimmi25

Anyone know the answers to these?

How will the composition of the hepatic portal vein and hepatic vein differ?

How will the composition of the hepatic artery and hepatic vein differ?

The hepatic portal vein contents will vary according to what has been absorbed in the stomach and intestines. The hepatic artery has oxygenated blood whilst the hepatic vein has de oxygenated blood.

Reply 844

JoshB

anyone know what any of the smaller 3 markers are likely to be?

Reply 845

123456786

the hardest topics in my opinion are the capillaries and the hepatic vein, anyone know any revision tips for them.....thanks :smile:

Reply 846

Laura-Robbie

would people agree with me that transpiration is less likely to come up as there was a big bit in it in january??

Reply 847

LifeIsGood

Original post by DoaaK

hate chapter 13.

It's actually relatively easy when you do lots of practice questions on it as it's mainly learning adaptations which is just regurgitation in the exam. However, it did take about 1.5 weeks to learn fully

Reply 848

ScienceGeek3

Original post by 123456786

the hardest topics in my opinion are the capillaries and the hepatic vein, anyone know any revision tips for them.....thanks :smile:

You do not need to revise the hepatic vein, simply know that it is the vein that comes from the liver. With capillaries try to relate them back to their function i.e. one cell thick, made of squamous cells this provides a short diffusion pathway which allows for efficient exchange of materials. Many capillaries provide a large surface area which increases the diffusion of metabolic materials. Narrow lumen which forces red blood cells to squeeze along the side shortening the diffusion pathway even further. :smile:

Reply 849

Kandy_Kain_94

Original post by maymaymo

me too please ! I hate tissue fluid.

Will do

Reply 850

Shopaholic94

Does anyone know how they got the answer to 3d on the Januray 2010 paper?! Its only one mark but I'm soo confused?!

Reply 851

Nugard123

Original post by Shopaholic94

Does anyone know how they got the answer to 3d on the Januray 2010 paper?! Its only one mark but I'm soo confused?!

Read the codes as triplets, and then see how many times each triplet occurs. The number of times it occurs is what the table means, you should be able to read off which amino acid it is then :smile:

Reply 852

ScienceGeek3

Original post by Shopaholic94

Does anyone know how they got the answer to 3d on the Januray 2010 paper?! Its only one mark but I'm soo confused?!

Its the DNA base coding one right? Well basically on figure 2 you should separate the bases into three's as every 3 bases code for 1 amino acid, therefore you should get, GTT, TAC, TAC, TCT, TCT, TCT, TTA. Now it tells you the name of the amino acid and the numbers it is present in. The first one is done for you i.e GTT codes for Gln. now the next 2 are TAC TAC and so they must code for Met as Met is present twice, again this data is in the table, the next three are all the same i.e TCT now in the table it tells you the only amino acid occuring three times is Arg so you put Arg 3 times and you are left with TTA coding for Asn. :smile:

Reply 853

maymaymo

Original post by Kandy_Kain_94

Will do

thank you!

Reply 854

Shopaholic94

That makes so much sense!

Reply 855

fretter778

Original post by Laura-Robbie

would people agree with me that transpiration is less likely to come up as there was a big bit in it in january??

I agree with you with wishful thinking. That was a resit paper though. There was nothing in the June 2010 paper so I reckon they'll stick something in for the 'first-timers'

Reply 856

cherri3

How do fish maintain a flow of water over the gills?

Can someone please explain that to me :smile:

Reply 857

TlanTlan

By swimming so water flows into their mouth and out through the gills?

Reply 858

ScienceGeek3

Original post by cherri3

How do fish maintain a flow of water over the gills?

Can someone please explain that to me :smile:

It is through inspiration, in brief, the mouth opens, the floor of the pharynx is lowered due to muscle contractions, the volume of the chamber increases, the pressure decreases and so water enters the mouth. The water then passes over the gills and exchange occurs :smile:

Reply 859