A level Biology: Post your doubts here!

[dornam]

No problem.
The thing is that ALL my notes are hardcopies and my notes are like bits of papers here and there. Tell me some specific chapter where i can put some explanations of my own and compile some of my personal notes.

Especially immunity if you can...

 

[strangerss]

strangerss and PhyZac - check this please.
View attachment 22519

Oh okay , I think I got it , apparently I stink in plan diagrams . Thanks a lot that was very beneficial I'll keep the points in my mind. My exam is on 28th of May. okay this is another plan diagram , do please tell if it satisfies the requirements , the drawing is given in paper 31 Oct/Nov 2009 , please do check it

 

[Amy Bloom]

Especially immunity if you can...

I can't promise you but i'll try my best because i have already closed my notes in boxes. ^^ I'll try my best and tag you.

 

[Amy Bloom]

Oh okay , I think I got it , apparently I stink in plan diagrams . Thanks a lot that was very beneficial I'll keep the points in my mind. My exam is on 28th of May. okay this is another plan diagram , do please tell if it satisfies the requirementsView attachment 22573View attachment 22573View attachment 22574 , the drawing is given in paper 31 Oct/Nov 2009 , please do check it

okay i'll be honest with you
- Your lines are good
- you were asked only TWO annotations (4tissues), be careful, labellings okay.
- I dunno why you drew two lines inside, i think its wrong, a single line would be okay. PhyZac what's your opinion?
- there was a small "hump" down the micrograph, you missed that
- However i wouldn't have drawn the vascular bundle as you did, rather like i did in the diagram i posted before. PhyZac what's your opinion?
- you respected the proportionality
Overall its good, keep practicing you'll be good

 

[daredevil]

yeah PhyZac and Amy Bloom now i see what u mean about the circle.. actually i was in a hurry so i didn't c it clearly but thot i shud post wat i think in case i forgot to do it afterwards..
anyways..
umm... i'm not so sure abt the lines. c when making a plan diagram all we're supposed to show is the position and the size of diferent tissues.... no tissue has its cells perfectly alligned in a smooth line but we just show the line as in the area covered by that tissue if it was picture perfect kindof smooth.... even he dermis does not have the cells in a perfect shape.. there are small and large epidermal cells with a minimal difference in size but still...
so i think u better confirm with soomeone..

maybe strangerss knows the answer to that

 

[Amy Bloom]

yeah PhyZac and Amy Bloom now i see what u mean about the circle.. actually i was in a hurry so i didn't c it clearly but thot i shud post wat i think in case i forgot to do it afterwards..
anyways..
umm... i'm not so sure abt the lines. c when making a plan diagram all we're supposed to show is the position and the size of diferent tissues.... no tissue has its cells perfectly alligned in a smooth line but we just show the line as in the area covered by that tissue if it was picture perfect kindof smooth.... even he dermis does not have the cells in a perfect shape.. there are small and large epidermal cells with a minimal difference in size but still...
so i think u better confirm with soomeone..

maybe strangerss knows the answer to that

Concerning the lines, that is why the lines that you draw shouldn't be kinda perfectly smooth, it must be somewhat wavy. However it depends on the specimen.
Otherwise, other comments/opinions are welcomed!

 

[PhyZac]

okay i'll be honest with you
- Your lines are good
- you were asked only TWO annotations (4tissues), be careful, labellings okay.
- I dunno why you drew two lines inside, i think its wrong, a single line would be okay. PhyZac what's your opinion?
- there was a small "hump" down the micrograph, you missed that
- However i wouldn't have drawn the vascular bundle as you did, rather like i did in the diagram i posted before. PhyZac what's your opinion?
- you respected the proportionality
Overall its good, keep practicing you'll be good

I was about to comment nearly similar to ur's
strangerss Keep it up, u did amazing !
If i was to draw i wudn't draw a double line, infact i wudn't draw any line,
and yes the hump is needed, my teacher scolded me when i forgot it
the vascular bundle ist wrong, u cud do it two ways, when i drew last time, i did as Amy bloom type, but teacher said to draw the way strangerss did.

 

[Amy Bloom]

I was about to comment nearly similar to ur's
strangerss Keep it up, u did amazing !
If i was to draw i wudn't draw a double line, infact i wudn't draw any line,
and yes the hump is needed, my teacher scolded me when i forgot it
the vascular bundle ist wrong, u cud do it two ways, when i drew last time, i did as Amy bloom type, but teacher said to draw the way strangerss did.

I think all of us know/remember the scoldings when we did plan diagrams
Well PhyZac i always drew vascular bundles this way and got no problems till my exams. Better ask somebody else's opinion.

 

[Malik777]

A sequence of amino-acids end in either an amino group (-NH2) or a carboxyl group (-COOH) . What is the theoretical number of chemically different dipeptides that may be assembled from 20 different amino acids?

A-40
B-80
C-160
D-400

 

[strangerss]

okay i'll be honest with you
- Your lines are good
- you were asked only TWO annotations (4tissues), be careful, labellings okay.
- I dunno why you drew two lines inside, i think its wrong, a single line would be okay. PhyZac what's your opinion?
- there was a small "hump" down the micrograph, you missed that
- However i wouldn't have drawn the vascular bundle as you did, rather like i did in the diagram i posted before. PhyZac what's your opinion?
- you respected the proportionality
Overall its good, keep practicing you'll be good

Yeah I didn't know I was supposed to draw that hump hehe. I don't understand what's an annotation , it means four tissue layers? because it's written two annotations to describe two tissues! thanks a lot for your opinion

 

[strangerss]

I was about to comment nearly similar to ur's
strangerss Keep it up, u did amazing !
If i was to draw i wudn't draw a double line, infact i wudn't draw any line,
and yes the hump is needed, my teacher scolded me when i forgot it
the vascular bundle ist wrong, u cud do it two ways, when i drew last time, i did as Amy bloom type, but teacher said to draw the way strangerss did.

So there isn't any cortex? that's the double line you're talking about right? Thank you so much for the encouragement

 

[Malik777]

A sequence of amino-acids end in either an amino group (-NH2) or a carboxyl group (-COOH) . What is the theoretical number of chemically different dipeptides that may be assembled from 20 different amino acids?

A-40
B-80
C-160
D-400

PhyZac plz answer :/

 

[PhyZac]

A sequence of amino-acids end in either an amino group (-NH2) or a carboxyl group (-COOH) . What is the theoretical number of chemically different dipeptides that may be assembled from 20 different amino acids?

A-40
B-80
C-160
D-400

The answer i think is D
since 20 x 20 is 400

did u get?

 

[PhyZac]

So there isn't any cortex? that's the double line you're talking about right? Thank you so much for the encouragement

Not so clear, i dont think so.

 

[strangerss]

I think all of us know/remember the scoldings when we did plan diagrams
Well PhyZac i always drew vascular bundles this way and got no problems till my exams. Better ask somebody else's opinion.

I think it depends on the specimen given , so I guess in each situation the situation the drawing differs , PhyZac in that specimen I guess we should draw what we saw that makes more sense

 

[strangerss]

Oh ok then thanks

Not so clear, i dont think so.

oh , okay then , thanks a lot , one more question , when drawing the epidermis , two lines should be drawn to represent the thickness right?

 

[Malik777]

The answer i think is D
since 20 x 20 is 400

did u get?

Yes Answer is D but , Plz Explain? :/

 

[PhyZac]

yup answer is D but Could You Explain it ? :/

See, it is hard to explain but imagine u had 2 aminoacid, lets call them Red and Blue
we can make
red red
red blue
blue blue
blue red

So as u see, 2 x 2....!!

Be carefull, be cause red blue....isnt like blue red
as they sed in the question..either end with amino group (-NH2) or a carboxyl group (-COOH)

 

[PhyZac]

Oh ok then thanks

oh , okay then , thanks a lot , one more question , when drawing the epidermis , two lines should be drawn to represent the thickness right?

Yup, to represent thickness, and because it is a distinctive tissue.
The way u did epidermis was right..!

 

[Malik777]

See, it is hard to explain but imagine u had 2 aminoacid, lets call them Red and Blue
we can make
red red
red blue
blue blue
blue red

So as u see, 2 x 2....!!

Be carefull, be cause red blue....isnt like blue red
as they sed in the question..either end with amino group (-NH2) or a carboxyl group (-COOH)

TY