A level Biology: Post your doubts here!

[Akshajistari]

I don't think that complete books will be available online
If you like I can give a link to the previous revision guides.

That would be amazing too

 

[nehaoscar]

Hi,
Anyone have an online copy for the new 2016 edition biology coursebook?
Or could anyone help me out with a scan copy of just a couple of the chapters that I require from the A2 portion please?
Regards

 

[My Name]

That would be amazing too

As soon as I find the link.

 

[My Name]

Hi,
Anyone have an online copy for the new 2016 edition biology coursebook?
Or could anyone help me out with a scan copy of just a couple of the chapters that I require from the A2 portion please?
Regards

Hi
I am sure because I have checked that an e book is not available for 2016.However if you like you can order from Amazon.
I also need the 2016 bit from the fourth edition.If I happen to take pictures of the new topics from a friends book I will surely share it here.In sha Allah.

 

[My Name]

You can check this link
https://www.xtremepapers.com/commun...ry-and-biology-revision-guides-updated.40762/
I hope that helps.
[Credits to Areeb Mohsin]

 

[shingiechingz@8]

guyz can you please help me with these questions
Describe with examples, the role of lipids in an organism 6 marks
Describe the molecular structure of starch 6 marks
Compare and contrast the structure of a typical plant and animal cell 6 marks
Describe the structure and function of the nucleus 6 marks

 

[My Name]

guyz can you please help me with these questions
Describe with examples, the role of lipids in an organism 6 marks
Describe the molecular structure of starch 6 marks
Compare and contrast the structure of a typical plant and animal cell 6 marks
Describe the structure and function of the nucleus 6 marks

Describe the molecular structure of starch

Starch is a polymer.The monomers that makes up starch are Amylose 20% and Amylopectin 80%.
They both have alpha glucose bonded differently.
Amylose has a helical structure with 1,4 glycosidic bonds.There are about 200-500 monomers in startch.
Amylopectin has 1,4 glycosidic bonds and 1,6 glycosidic bonds however Amylopectin is branched.Nearly 5000-100000 monomers.
I think as it is SIX marks you could mention things like starch is compact,insoluble in water...

 

[My Name]

guyz can you please help me with these questions
Describe with examples, the role of lipids in an organism 6 marks
Describe the molecular structure of starch 6 marks
Compare and contrast the structure of a typical plant and animal cell 6 marks
Describe the structure and function of the nucleus 6 marks

Describe with examples, the role of lipids in an organism 6 marks
They are used as energy storage.They have more energy per gram than polysacchrides.Thus they store more in less mass.
Thay provide insulation (in endothermic organisms) the lipid is stored below the body surface as adipose tissue.
In the form of layers they give protection to organisms for example kidneys.
They are less dense than water ,they have more buoyancy which helps animals to float.
They are found in the cell surface membrane of cells in the form of phospholipid bilayer.
One point is missing. :/

I will answer the rest soon In sha Allah.

 

[shingiechingz@8]

Describe with examples, the role of lipids in an organism 6 marks
They are used as energy storage.They have more energy per gram than polysacchrides.Thus they store more in less mass.
Thay provide insulation (in endothermic organisms) the lipid is stored below the body surface as adipose tissue.
In the form of layers they give protection to organisms for example kidneys.
They are less dense than water ,they have more buoyancy which helps animals to float.
They are found in the cell surface membrane of cells in the form of phospholipid bilayer.
One point is missing. :/

I will answer the rest soon In sha Allah.

thanks..... you really helped me a lot..
other examples of lipids i know are triglycerides which are storage compounds for the energy reserve of the body.
they also occur as components of enzyme systems
source of fat soluble vitamins.....
and steroids

 

[My Name]

thanks..... you really helped me a lot..
other examples of lipids i know are triglycerides which are storage compounds for the energy reserve of the body.
they also occur as components of enzyme systems
source of fat soluble vitamins.....
and steroids

Oh I am sorry I did not give attention to the example part.
Good to know it helped.

 

[nehaoscar]

Hi
I am sure because I have checked that an e book is not available for 2016.However if you like you can order from Amazon.
I also need the 2016 bit from the fourth edition.If I happen to take pictures of the new topics from a friends book I will surely share it here.In sha Allah.

Thankyou

 

[shingiechingz@8]

in each case , state the letter which indicates the site of
the krebs cycle
oxidative phosphorylation
decarboxylation

suggest one function of circular DNA

 

[nehaoscar]

For transmission of impulses in neurons, the shorter the refractory period, the higher the frequency right?

 

[Akshajistari]

You can check this link
https://www.xtremepapers.com/commun...ry-and-biology-revision-guides-updated.40762/
I hope that helps.
[Credits to Areeb Mohsin]

Thank you

 

[qwertypoiu]

in each case , state the letter which indicates the site of
the krebs cycle
oxidative phosphorylation
decarboxylation

suggest one function of circular DNA

The Krebs Cycle occurs in the mitochondrial matrix = S
The oxidative phosphrylation happens in the inner membrane or cristae = R
Decarboxylation happens in the link reaction where the pyruvate (3C) has a carbon atom removed to form (after a series of steps) an acetyl compound. This occurs in the mitochondrial matrix = S

A role of circular DNA in mitochondria could be to contain the genetic code of enzymes required during respiration, such as acetyl CoA. So it aids with its synthesis.

 

[qwertypoiu]

For transmission of impulses in neurons, the shorter the refractory period, the higher the frequency right?

Yes that makes sense to me!

 

[shingiechingz@8]

Guyz more questions
Describe the structure and function of the endosplasmic reticulum 6 marks
Explain the roles of the Golgi apparatus 6 marks
outline the calvin cycle 6 marks

 

[shingiechingz@8]

fig shows the relationship between parts of neurones
Name H and F [2]
Describe how a nerve impulse passes from cell A to cell B [4]

 

[qwertypoiu]

View attachment 57743 View attachment 57743
fig shows the relationship between parts of neurones
Name H and F [2]
Describe how a nerve impulse passes from cell A to cell B [4]

Is it neurotransmitter and receptor?
Or perhaps Acetylcholine and receptor??

 

[shingiechingz@8]

guys where can l find some old biology past exam papers like from 1995-1998