A level Biology: Post your doubts here!

[Hisham Khan]

Smoking doesen't reduce the surface area available directly.
So B is the only option left

 

[SohaibButt]

Smoking doesen't reduce the surface area available directly.
So B is the only option left

I was just confused lung cancer affect the epithelial cell results cancer so it doesn't directly affect isn't it?

 

[SohaibButt]

Smoking doesen't reduce the surface area available directly.
So B is the only option left

I got it thanks dude

 

[angryrider_56]

I was just confused lung cancer affect the epithelial cell results cancer so it doesn't directly affect isn't it?

Also dont forget...cancer forms tumors which of course decreases the surface area

 

[ShahdNaasan]

can someone explain this question please ? The largest organelle is nucleus so that would be in solid pellet 1 the next largest is mitochondrion(as in an animal cell no chloroplasts) so solid pellet 2 is mitochondrion then the next largest is nucleolus so thats solid pellet 3 and solid pellet 4 is the lysosomes isnt it ? the examiner report says that in solid pellet 4 its the ribosome thus the answer is D synthesis of protein . Can anyone explain why ?

 

[A*****]

can someone explain this question please ? The largest organelle is nucleus so that would be in solid pellet 1 the next largest is mitochondrion(as in an animal cell no chloroplasts) so solid pellet 2 is mitochondrion then the next largest is nucleolus so thats solid pellet 3 and solid pellet 4 is the lysosomes isnt it ? the examiner report says that in solid pellet 4 its the ribosome thus the answer is D synthesis of protein . Can anyone explain why ?View attachment 63806

Maybe the nuclear envelope is also broken down or else how would the nucleolus in C be obtained

 

[A*****]

I know that antibodies are broken down but how is statement 1 wrong? The answer is C




Plz explain the graph for velocity and area anyone
Answer is C

 

[ShahdNaasan]

View attachment 63807

I know that antibodies are broken down but how is statement 1 wrong? The answer is C


View attachment 63809

Plz explain the graph for velocity and area anyone
Answer is C

For 35
Immunity cannot be inherited because the person has to show an immune response to gain immunity ( develop memory B lymphocytes and memory T lymphocytes)
Statement 1 says immunity can be inherited which is wrong thats why option C is correct

 

[innovative_1]

View attachment 63807

I know that antibodies are broken down but how is statement 1 wrong? The answer is C


View attachment 63809

Plz explain the graph for velocity and area anyone
Answer is C

Immunity is not inherited because no transfer of genes it is only sharing of the blood

 

[innovative_1]

View attachment 63807

I know that antibodies are broken down but how is statement 1 wrong? The answer is C


View attachment 63809

Plz explain the graph for velocity and area anyone
Answer is C

Capillaries have always greater cross sectional area as they r network of blood vessels

 

[ShahdNaasan]

View attachment 63807

I know that antibodies are broken down but how is statement 1 wrong? The answer is C


View attachment 63809

Plz explain the graph for velocity and area anyone
Answer is C

For 27
You can definitely identify Y as the velocity of blood flow because the velocity of blood flow is slowest in capillaries giving time for exchange of substances to happen so definitely it would be C

 

[innovative_1]

View attachment 63807

I know that antibodies are broken down but how is statement 1 wrong? The answer is C


View attachment 63809

Plz explain the graph for velocity and area anyone
Answer is C

Velocity gradually decreases as blood moves away from the heart the blood pressure decreases across the capillaries bcoz lumen decreases blood is divided into the networks in addition substances pass out of the capillaries so obviously blood pressure decreases

 

[A*****]

Sorry but I'm a lil bit confused about the cross sectional area...is it the area of the whole vessel or just it's lumen? And if it is the whole, then how can capillaries have the maximum?

 

[Hisham Khan]

View attachment 63807

I know that antibodies are broken down but how is statement 1 wrong? The answer is C


View attachment 63809

Plz explain the graph for velocity and area anyone
Answer is C

antibodies are not inherited as the famous indian saying itself says:bobs haha xD.
Basically it's by transfer of blood or colustrum by which babies get it

 

[kirzzz]

Alvel

It's 10

oh aight

 

[Hisham Khan]

Sorry but I'm a lil bit confused about the cross sectional area...is it the area of the whole vessel or just it's lumen? And if it is the whole, then how can capillaries have the maximum?

I don't think you need to go that deep lul

 

[kirzzz]

need help!


(9700/12/M/J/14)

Q37) An antiserum to a snake toxin can be obtained by injecting the toxin into a horse. The antiserum is made from blood plasma taken from the horse a few weeks later. The antiserum is injected into a person who has been bitten by the same species of snake.

What type of immunity occurs as a result of this antiserum?

A) artificial active
B) artificial passive
C) natural active
D) natural passive

answer is B

 

[Hisham Khan]

As it is not produced naturally and is injected,it is artificial.
Now antibodies are introduced directly through injection,not pathogen against which body itself produce antibodies,so Artifical PASSIVE

 

[Hisham Khan]

I'm bored....

 

[angryrider_56]

Guys why not D?