Physics, Chemistry and Biology: Post your doubts here!

[AAnsarii]

ne particularly difficult pprs 4 bio or chem? plz post 'em here
thx

 

[IGSCE.Geek.]

can anyone aid me in a qs?? its OCT/NOV 2006 QU 9

 

[thats_me]

can anyone aid me in a qs?? its OCT/NOV 2006 QU 9

subject?

 

[IGSCE.Geek.]

chem, while your at it could u help me in q11 as well?

 

[za Shadow]

plllllllllzzzzzzzzz heeeeelllllpppp
bio
J 1994 21) why D not C ???????????
26) why B not C ?????????
Nov 1994 28 whyyyy D ?????????
J 1995 39 what are landslides ?????????
nov 1996 23 why D not C ???????
nov 1999 8 why D not A ???????????
and 37 why D not B ???????
J 2000 13 why B not A and which one is the xylem and which is the phloem ??????
17 i don't understand when does the stomata open and close in general
27 whhhhhyyyyyy D ????????????
nov 2000 38 B and D r both correct so why its B ??????????
nov 01 38 why C not A ???????????

plllllllzzzzzzzzzz heeeellllllpppp meeeeee !!!!!!! plzzzzzzzzzzzzz i need ur heeeellllllppp

 

[thats_me]

chem, while your at it could u help me in q11 as well?

sure Here..
9 : Mg has the oxidation no. 2+ so it needs to loose 2 electron Cl has the oxidation no. 1- so it needs to gain one electron
So MgCl2 as 2 Cl are needed to take two of Mg's electron ,the same goes for Sulphur chloride SCl2 ,Ans: D
11: NaCl (conc) so at anode forms chlorine and at cathode forms hydrogen and solution of sodium hydroxide ,Ans: A

 

[IGSCE.Geek.]

my bad its oct/nov 2007 q11

 

[IGSCE.Geek.]

plllllllllzzzzzzzzz heeeeelllllpppp
bio
J 1994 21) why D not C ???????????
26) why B not C ?????????
Nov 1994 28 whyyyy D ?????????
J 1995 39 what are landslides ?????????
nov 1996 23 why D not C ???????
nov 1999 8 why D not A ???????????
and 37 why D not B ???????
J 2000 13 why B not A and which one is the xylem and which is the phloem ??????
17 i don't understand when does the stomata open and close in general
27 whhhhhyyyyyy D ????????????
nov 2000 38 B and D r both correct so why its B ??????????
nov 01 38 why C not A ???????????

plllllllzzzzzzzzzz heeeellllllpppp meeeeee !!!!!!! plzzzzzzzzzzzzz i need ur heeeellllllppp

do have the mark scheme?

 

[thats_me]

my bad its oct/nov 2007 q11

Ohkaye For this
try balancing these equations one by one
So lets try A: C5H11OH +8O2--->5CO2+6H2O (first balance carbon then hydrogen but Oxygen doesn't balance)
try B: C6H9OH +8O2--->6CO2 + 5H2O BALANCED!! so Ans is B

 

[IGSCE.Geek.]

do have the mark scheme?

its D because C is Egestion (removal of undigested food....to anus)
but they're asking you about excretion! thats different its the removal of TOXIC UNWANTED WASTE PRODUCTS...A.K.A. DIGESTED FOOD OUT OF THE BODY... understood?

 

[IGSCE.Geek.]

Ohkaye For this
try balancing these equations one by one
So lets try A: C5H11OH +8O2--->5CO2+6H2O (first balance carbon then hydrogen but Oxygen doesn't balance)
try B: C6H9OH +8O2--->6CO2 + 5H2O BALANCED!! so Ans is B

thanks your really helpful! hopefully you will do well

 

[IGSCE.Geek.]

plllllllllzzzzzzzzz heeeeelllllpppp
bio
J 1994 21) why D not C ???????????
26) why B not C ?????????
Nov 1994 28 whyyyy D ?????????
J 1995 39 what are landslides ?????????
nov 1996 23 why D not C ???????
nov 1999 8 why D not A ???????????
and 37 why D not B ???????
J 2000 13 why B not A and which one is the xylem and which is the phloem ??????
17 i don't understand when does the stomata open and close in general
27 whhhhhyyyyyy D ????????????
nov 2000 38 B and D r both correct so why its B ??????????
nov 01 38 why C not A ???????????

plllllllzzzzzzzzzz heeeellllllpppp meeeeee !!!!!!! plzzzzzzzzzzzzz i need ur heeeellllllppp

ITS B BECAUSE OVULATION IS WHEN THE EGG IS RELEASED FROM THE OVARY, PASSES ALONG THE OVIDUCT BY THE CILIA...AND IF FERTILIZED BY SPERM, THEN IT WILL BE IMPLANTED TO FORMA FETUS IF NOT..WELL THEN, TAKES AN EXIT DOWN THE TOILET WITH A BUS OF THE MENSTRUAL CYCLE... DAY 16, OESTROGEN HELPS IN REBUILDING THE UTERUS LINING...

 

[thats_me]

thanks your really helpful! hopefully you will do well

Ur welcum n thankyuh!

 

[za Shadow]

do have the mark scheme?

http://www.scribd.com/doc/3169216/Bio-Ans-P1-P3-P6-19932003

 

[Rahma Abdelrahman]

plllllllllzzzzzzzzz heeeeelllllpppp
bio
J 1994 21) why D not C ???????????
26) why B not C ?????????
Nov 1994 28 whyyyy D ?????????
J 1995 39 what are landslides ?????????
nov 1996 23 why D not C ???????
nov 1999 8 why D not A ???????????
and 37 why D not B ???????
J 2000 13 why B not A and which one is the xylem and which is the phloem ??????
17 i don't understand when does the stomata open and close in general
27 whhhhhyyyyyy D ????????????
nov 2000 38 B and D r both correct so why its B ??????????
nov 01 38 why C not A ???????????

plllllllzzzzzzzzzz heeeellllllpppp meeeeee !!!!!!! plzzzzzzzzzzzzz i need ur heeeellllllppp

1 - removal of undigested food is egestion, not excretion; recall the definition of excretion
2 - I believe it is C, after ovulation
3 - As leaves have developed and the plant is able to photosynthesise
4 - Similar to soil erosion
5 - If you chose C, then you are suggesting that there is no bending, bending is due to unequal distribution of auxin.
6 - as cell wall is fully permeable and will allow any surrounding solution in, NOT Air!
7 - Answer is B, we discussed this previously in detail, this Q. is repeated in one of the recent papers and answer is B.
8 - Xylem is W and phloem is X, therefore water travels from W(xylem) to Y(stomata) during transpiration.
9 - Stomata is open during the day to absorb maximum CO2 for photosynthesis (if u hve further doubt on this ask again, I will explain in more detail!)
10 - Same as 1994 (explained above)
11 - Deforestation doesn't cause an increase in SO2 , actually SO2 has nothing to do with plants.
12 - I was earlier confused here too, but my last year's teacher said we have to choose the most appropriate answer.
Hope this helps ! Any further doubts, Please ASK!

 

[thats_me]

za Shadow Here..
s 1994 21:C is egestion not excretion ,excretion is the removal of waste substances
26 :As ovulation starts then
w 1994 28 : As in D it's fully grown it can photosynthesis
s 1995 39: I think It's the movement of rocks and dirt down a slope
w 1996 23: Auxins accumulate in the darker side
w 1999 37: this question is repeated in the latest papers &the answer is B
s 2000 13: X is xylem &W is phloem so from xylem to stomata
17: I think it's B cause wen light intensity increases stomata opens for the diffusion of gases
27 : As it is fully grown up can photosynthesis ,make food..
w 2000 38 : If no trees then no transpiration D is not possible sulphurdioxide is not released from trees
w2001 38 : As in the graph thickness decreases after DDT is added

 

[AAnsarii]

w09_qp11 q20, how do u noe dat in Q, it'll stay still?
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Biology (0610)/0610_w09_qp_11.pdf

 

[AAnsarii]

functions of glucagon n insulin plz..

 

[joulie]

it's comin 4m d anther of d same flower, n it doesn't happen internally, d pollen must fall on d stigma, which is d case in D.

1. Characteristics of insects:
2. 1. 3 body parts
   2. one pair of antennae
   3. compound eyes
   4. mandibles
   5. thorax
3. 6.exoskeleton
4. 7.open circulatory system
5. so dis doesnt mean dat d thing NEEDs 2 have wings 2 b an insect, c 4 instance ants., so d 1st organism is also an insect

​

for the first Question i cant see the stigma where the pollen must fall in part D
and for the second question i couldn't distingiush any of those insect characteristics on them like they all have things that look like antennae and crustacians also have comound eyes plz help

 

[AAnsarii]

for the first Question i cant see the stigma where the pollen must fall in part D
and for the second question i couldn't distingiush any of those insect characteristics on them like they all have things that look like antennae and crustacians also have comound eyes plz help

also insects have 3pair of legs, 1 pair of antennae, d1st 1 has those, so i guess thats it.