A level Biology: Post your doubts here!

[mimi1077]

so the practical only exists in the as-level not in the a-level that is what i wanted to know because my school claims that there are two practicals one in the as-level and the other in the a-level and i thought it is only in the as-level(i already finished as level)??

 

[Atiqa asl]

so the practical only exists in the as-level not in the a-level that is what i wanted to know because my school claims that there are two practicals one in the as-level and the other in the a-level and i thought it is only in the as-level(i already finished as level)??

yup we have only 1 practical that is in as but in alevel we have to write the setup and how to carry out the experiment that is in paper 5

 

[Atiqa asl]

but chill both papers have low weightage so we actually don't have to worry much for paper 3 and 5

 

[mimi1077]

but chill both papers have low weightage so we actually don't have to worry much for paper 3 and 5

thankyouu for your support )

 

[sarapippin]

Can someone please give me a step by step guide for using the microscope during the AS practical , graticule unit and all please :/

 

[Senuralp]

Hi everyone, assalamoalaikum!!

To get things organized in a better way, I am making this thread. As othewise, some queries remain unanswered!

So post your A LEVEL BIOLOGY doubts in this thread. InshaAllah those who can , will help me and you all.

Will try to update this soon, by adding links to some Biology Notes & Links around the forum.

Thanks!
Jazak Allah Khair!

BIOLOGY LINKS & NOTES :


B!0l0gy $l!de$ & N0te$... - by workinghard

Biology Practical notes!! - by libra94

http://www.biologymad.com

http://www.biologyinnovation.co.uk

Action Potential - Notes

How is an active potential made in a presynaptic neurone?

 

[Senuralp]

Hi everyone, assalamoalaikum!!

To get things organized in a better way, I am making this thread. As othewise, some queries remain unanswered!

So post your A LEVEL BIOLOGY doubts in this thread. InshaAllah those who can , will help me and you all.

Will try to update this soon, by adding links to some Biology Notes & Links around the forum.

Thanks!
Jazak Allah Khair!

BIOLOGY LINKS & NOTES :


B!0l0gy $l!de$ & N0te$... - by workinghard

Biology Practical notes!! - by libra94

http://www.biologymad.com

http://www.biologyinnovation.co.uk

Action Potential - Notes

How is an active potential made in a presynaptic neurone?

 

[animesh]

hey can you plz help me with transportation and genetics

 

[mynameisjh]

Studies on the energy efficiency of raising catfish in ponds have shown that only 15-20% of the energy taken in by the catfish population in their food is used to increase their total biomass.
(i) Explain why only some of the energy taken in by the catfish is used to increase biomass.
(ii) In the wild only about 10% of the energy taken in by the catfish in their food is used to increase biomass. Suggest why this percentage us lower in the wild than in the pond.

Can anyone help me with these questions please? It's from the past years. I have the answer though but i dont really understand the question

 

[6Astarstudent]

Studies on the energy efficiency of raising catfish in ponds have shown that only 15-20% of the energy taken in by the catfish population in their food is used to increase their total biomass.
(i) Explain why only some of the energy taken in by the catfish is used to increase biomass.
(ii) In the wild only about 10% of the energy taken in by the catfish in their food is used to increase biomass. Suggest why this percentage us lower in the wild than in the pond.

Can anyone help me with these questions please? It's from the past years. I have the answer though but i dont really understand the question

1. Animals (catfish) use energy not only from growth (increase biomass), but also from respiration, excretion and many other living processes, so only some parts of the energy is used to increase the biomass.
2. Now you compare the data, 15%-20% energy used to increase biomass if the fish lives in the pond, and only 10% energy used to increase biomass if in the wild.
It is obviously that living is more important than growth, that means that feeding ( eating and finding food), escaping predators and respiration always come first.
In the wild, the space is bigger (not a limited space like the pond) so the fish has to move bigger distances to find food which uses more energy. The fish also needs to escape predators which use energy, so less energy is left for growth.

 

[AmeeraKhan]

Respiration and ATP notes? The Cambridge text (Mary jones) book is really vague....

 

[mynameisjh]

thank you!!!

1. Animals (catfish) use energy not only from growth (increase biomass), but also from respiration, excretion and many other living processes, so only some parts of the energy is used to increase the biomass.
2. Now you compare the data, 15%-20% energy used to increase biomass if the fish lives in the pond, and only 10% energy used to increase biomass if in the wild.
It is obviously that living is more important than growth, that means that feeding ( eating and finding food), escaping predators and respiration always come first.
In the wild, the space is bigger (not a limited space like the pond) so the fish has to move bigger distances to find food which uses more energy. The fish also needs to escape predators which use energy, so less energy is left for growth.

 

[Unreal]

O/N 2012 P22 Q6 asks to label a heart diagram after a coronary artery bypass. Could someone please upload the correct one because the marking scheme doesn't give it. I need it ASAP exam is tomorrow!

 

[6Astarstudent]

O/N 2012 P22 Q6 asks to label a heart diagram after a coronary artery bypass. Could someone please upload the correct one because the marking scheme doesn't give it. I need it ASAP exam is tomorrow!

 

[Unreal]

Thank you so much but what about X?

 

[6Astarstudent]

Thank you so much but what about X?

Just Above the joint I marked B on the coronary artery.

 

[Unreal]

Just Above the joint I marked B on the coronary artery.

great Thanks again

 

[6Astarstudent]

great Thanks again

np, just ask if you have any questions. I'm too lazy to find interesting/challenging questions myself to tutor my mate tomorrow.

 

[Dukeofwin]

Q: describe the way in which the nucleotide sequence codes for the amino acid sequence in a polypeptide
with reference to the nucleotide sequence for HbA (normal) and HbS (sickle cell) alleles of the gene for
the β -haemoglobin polypeptide.

(This is from Syllabus! Could anyone answer this?)

 

[Dukeofwin]

And also this :
Q: state that a gene is a sequence of nucleotides as part of a DNA molecule, which codes for a polypeptide
and state that a mutation is a change in the sequence that may result in an altered polypeptide