A level Biology: Post your doubts here!

[A*****]

but doesnt nucleus disappears at prophase and reforms at telophase?
do you know the year this question is from?

It's winter 2002 q16 and its answer is D...just confirmed from the mark scheme

 

[kirzzz]

View attachment 63783
Is the answer B or D? (i dont have the MS for this)

the answer is D

 

[kirzzz]

View attachment 63783
Is the answer B or D? (i dont have the MS for this)

during telophase, the nucleus divides into two so each chromatid goes into two daughter cells therefore, the dna content of one cell decreases, which is represented on the graph by the sudden drop. this is why the answer is D

 

[A*****]

Isn't X RER??

 

[kirzzz]

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Isn't X RER??

yes, X is rough endoplasmic reticulum. the function of the rough endoplasmic reticulum is to manufacture proteins as well as transport them via vesicles so the answer is D

 

[angryrider_56]

Thank you guys so much for the reply

 

[A*****]

yes, X is rough endoplasmic reticulum. the function of the rough endoplasmic reticulum is to manufacture proteins as well as transport them via vesicles so the answer is D

But the mark scheme says it's A

 

[angryrider_56]

Guys can u confirm my answers? (These are classifieds and their MS is unreliable)
47-A
33-B
37-D
right?

 

[angryrider_56]

But the mark scheme says it's A

If X is pointing at ribosomes only then it's protein synthesis, if it's pointing at the ER then it's protein synthesis and transportation so it's either C or D not A or B at all...
is ur marking scheme the actual MS or a topical paper MS?

 

[kirzzz]

If X is pointing at ribosomes only then it's protein synthesis, if it's pointing at the ER then it's protein synthesis and transportation so it's either C or D not A or B at all...
is ur marking scheme the actual MS or a topical paper MS?

agreed!

 

[kirzzz]

View attachment 63785
Guys can u confirm my answers? (These are classifieds and their MS is unreliable)
47-A
33-B
37-D
right?

47 and 33 are definitely correct but im not really sure about 37

 

[kirzzz]

But the mark scheme says it's A

never thought id say this but i think the marking scheme youre referring to is wrong. lipid synthesis only occurs in mitochondria and smooth endoplasmic reticulum and the label doesnt point to either of these organelles

 

[A*****]

Ohhhhh I'm really sorry guys, it was D
Sorry for disturbing

 

[kirzzz]

Ohhhhh I'm really sorry guys, it was D
Sorry for disturbing

hehe, its okay. glad i could help X

 

[A*****]

So it's C here


Just wanted to confirm that are alveoli inflamed during emphysema? And what about bronchi...are they too inflamed??

 

[ShahdNaasan]

Can anyone explain this question?

 

[kirzzz]

Can anyone explain this question?
View attachment 63790

tar in cigarette smoke damages the gas exchange system. it inhibits the function of the cilia and stimulates goblet cells to secrete more mucus, which means that tar directly affects ciliated epithelial cells (labelled as Y in the diagram) and goblets cells (labelled as X in the diagram). so the answer is B (i guess)!

 

[kirzzz]

So it's C here
View attachment 63787

Just wanted to confirm that are alveoli inflamed during emphysema? And what about bronchi...are they too inflamed??

i just did this question and got pretty confused. thought the answer was D but marking scheme says its C. thought only emphysema damages the alveoli but turns out chronic bronchitis too damages the alveoli

 

[A*****]

i just did this question and got pretty confused. thought the answer was D but marking scheme says its C. thought only emphysema damages the alveoli but turns out chronic bronchitis too damages the alveoli

But I think inflammation does not occur in chronic bronchitis

 

[kirzzz]

But I think inflammation does not occur in chronic bronchitis

yes, youre correct