A level Biology: Post your doubts here!

[Mohammed salik]

yes sir! G .

Lol! Sir Toh Ap Hein Hamare!

 

[princeali97]

Lol! Sir Toh Ap Hein Hamare!

Tum itni Bayzti mat karo meri bhai
Parho parho..

 

[Exo_luhan]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s12_qp_21.pdf
Why can't we write about magnification of EM is more than LM in Q2A?

 

[Exo_luhan]

Function of cell sap?

 

[Mohammed salik]

Hahah..! Nahi Bayzti Nahi Kar raha Tha! !

Tum itni Bayzti mat karo meri bhai
Parho parho..

 

[Mohammed salik]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w13_qp_22.pdf

Q2 b)ii) I need a Model Ans!
Thnx in Advance!

Karim Nabil!!

 

[Mohammed salik]

Function of cell sap?

The sap has many functions, including storage of useful materials, and provides mechanical support for plants.

 

[maiso11]

paper 22 O/N 2012 3)a)i) why doesnt the arrow move from phytoplankton to kryll?

 

[thats_me]

paper 22 O/N 2012 3)a)i) why doesnt the arrow move from phytoplankton to kryll?

Who says it does not?

 

[maiso11]

Who says it does not?

the marking scheme....

 

[Mohammed salik]

the marking scheme....

No it doesnt.. Plz recheck !

 

[Karim Nabil]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s12_qp_21.pdf
Why can't we write about magnification of EM is more than LM in Q2A?

because resolution is the ability to differentiate between two points not magnification

 

[princeali97]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s12_qp_21.pdf
Why can't we write about magnification of EM is more than LM in Q2A?

Look whenever they talk about internal membranes or internal structure or why light microscope cannot be used to see ribosomes you have to mention about resolution becuz the resolving power depends on wavelength and u must know resolution is inversely proportional to wavelength and wavelength of electrons is shorter than of light and so it has a greater resolving power.

 

[princeali97]

Why cells that are produced as a result 0f mitosis are genetically identical?

 

[joanna omar]

Why cells that are produced as a result 0f mitosis are genetically identical?

To ensure cells are gentically same having same gentic material as parents
To avoid any mutation occuring

 

[joanna omar]

http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_s06_qp_2.pdf

Help me out in Q5 (a)

 

[Karim Nabil]

Why cells that are produced as a result 0f mitosis are genetically identical?

• to avoid mutations
• to avoid formation of a disease e.g. sickle cell anaemia, or cancer
• to avoid tissue rejection by the immune system
• to avoid formation of an altered protein

 

[joanna omar]

• to avoid mutations
• to avoid formation of a disease e.g. sickle cell anaemia, or cancer
• to avoid tissue rejection by the immune system
• to avoid formation of an altered protein

well that's better more detailed

 

[Karim Nabil]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s06_qp_2.pdf

Help me out in Q5 (a)

urease converts urea into ammonia by deamination
ammonia is converted into nitrite then into nitrate by the help of nitrobacter/nitrosomonas bacteria, this is nitrification process

 

[princeali97]

• to avoid mutations
• to avoid formation of a disease e.g. sickle cell anaemia, or cancer
• to avoid tissue rejection by the immune system
• to avoid formation of an altered protein

sorry to say but its a completely wrong answer..You have answered the consequences of uncontrolled mitotic division.
U have to explain why the cells after mitosis are identical.Its because of semi-conservative replication.And then u describe it.And i was asking for that description.Heres the question.q1 (b)(ii)...http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_w07_qp_2.pdf