Biology MCQ thread..!!

[Romeo10]

32

I think this is good if this is the standard as I expect that bio paper 1 will come hard just like the other papers :S

 

[ivorydale]

Can someone pleaseeee help with question 22 on this paper?

http://www.xtremepapers.me/CIE/Internat ... _qp_12.pdf

Why is C correct?

Because, after transcription, the original DNA molecule is NOT changed. The information on the DNA molecule is simply "copied" in the mRNA as codons

 

[sweetiepie]

Why lysine described as an essential aminoaciD?
A it cannot be synthesised in the human body
B it is necessary component of cell surface membranes
C it is found in all human structural proteins
D it is used in the synthesis of peptide hormones

explain me....

 

[Fauziya]

Why lysine described as an essential aminoaciD?
A it cannot be synthesised in the human body
B it is necessary component of cell surface membranes
C it is found in all human structural proteins
D it is used in the synthesis of peptide hormones

explain me....

i think its A.. its jst a guess..i dnt knw the reason :Search:

 

[tasnim007]

i thnk its C
this is because lysine is used to make collagen as structural proteins for bones and artery

 

[angelgurl]

Lysine, or L-lysine, is an essential amino acid. That means it is necessary for human health but the body can't manufacture it; so its A i googled this!
open this link

http://www.umm.edu/altmed/articles/lysine-000312.htm

it isnt opening at my place though

 

[sweetiepie]

thanks love ya sis itx opening for me n help me i have still doutss reply me in pm plzzzzzzzzz....

 

[angelgurl]

essential amino acid - an amino acid that is required by animals but that they cannot synthesize; must be supplied in the diet
saw the definition!

 

[Otaiba13]

hey ppl can u pls help me with these
thanks in advance

O/N 04 q38 how do we get D
A square metre of grassland receives about 1 047 000 kJ of solar light energy each year.
The table shows what happens to this energy.
used in evaporation of water 523 500 kJ
transmitted to the ground 335 000 kJ
reflected by the leaves 165 000 kJ
used for growth 21 500 kJ
used for other life processes 1 500 kJ
respiratory heat losses 500 kJ
How much energy is used by the grass in photosynthesis?
A 2000 kJ B 19 500 kJ C 21 500 kJ D 23 500 kJ

O/N 07 q 39 ans is B
Following an environmental disaster of a major volcanic eruption, the atmosphere contains
greatly increased amounts of dust.
How does this affect the following organisms?
nitrifying bacteria primary consumer producer secondary consumer
A decrease increase increase increase
B increase decrease decrease decrease
C increase no change no change decrease
D no change increase decrease no change

M/J 09
q7 ans is C
What is the general formula for starch?
A (C5H10O5)n B (C5H10O6)n C (C6H10O5)n D (C6H12O6)n

q34 ans is A but y not B
A graft of tissue, such as skin, from a different person is usually rejected by the body.
Which statement about graft rejection is correct?
A The graft is rejected by T-lymphocytes because they circulate in the blood and can gather at
the graft site.
B The graft is rejected by B-lymphocytes because they make and release antibodies which
react with the surface antigens on the graft cells.
C The graft is rejected by B-lymphocytes because T-lymphocytes are not stimulated to produce
antibodies.
D The graft is rejected by T-lymphocytes because the graft tissue causes T-lymphocytes to
release antibodies

 

[Otaiba13]

What determines the rate of water movement from the roots to the leaves?
A absorption of water through the root hair cells
B development of a less negative water potential in the leaves
C diffusion of water through the stomata
D evaporation of water from the mesophyll cell walls

 

[libra94]

D

 

[ivorydale]

can any1 tell me the ans for ques 1. How is it A?
here's the link:
http://www.xtremepapers.me/CIE/Internat ... 8_qp_1.pdf

 

[NinaCheng]

greatest number of cells in field of view = as many cells as you can see

so it has to be the lowest magnification to see as many cells as you can

(in my opinion anyway)

 

[guigao1994]

hey ppl can u pls help me with these
thanks in advance

O/N 04 q38 how do we get D
A square metre of grassland receives about 1 047 000 kJ of solar light energy each year.
The table shows what happens to this energy.
used in evaporation of water 523 500 kJ
transmitted to the ground 335 000 kJ
reflected by the leaves 165 000 kJ
used for growth 21 500 kJ
used for other life processes 1 500 kJ
respiratory heat losses 500 kJ
How much energy is used by the grass in photosynthesis?
A 2000 kJ B 19 500 kJ C 21 500 kJ D 23 500 kJ

O/N 07 q 39 ans is B
Following an environmental disaster of a major volcanic eruption, the atmosphere contains
greatly increased amounts of dust.
How does this affect the following organisms?
nitrifying bacteria primary consumer producer secondary consumer
A decrease increase increase increase
B increase decrease decrease decrease
C increase no change no change decrease
D no change increase decrease no change

M/J 09
q7 ans is C
What is the general formula for starch?
A (C5H10O5)n B (C5H10O6)n C (C6H10O5)n D (C6H12O6)n

q34 ans is A but y not B
A graft of tissue, such as skin, from a different person is usually rejected by the body.
Which statement about graft rejection is correct?
A The graft is rejected by T-lymphocytes because they circulate in the blood and can gather at
the graft site.
B The graft is rejected by B-lymphocytes because they make and release antibodies which
react with the surface antigens on the graft cells.
C The graft is rejected by B-lymphocytes because T-lymphocytes are not stimulated to produce
antibodies.
D The graft is rejected by T-lymphocytes because the graft tissue causes T-lymphocytes to
release antibodies

first question: photosynthesis produces energy, right? so we must look to the values related to a loss of energy by the plant. These values are : used for growth 21 500 kJ
used for other life processes 1 500 kJ respiratory heat losses 500 kJ.
Add them up: 23500 kJ. The other values have nothing to do, they are just "waste" of energy.

second question: I dont know how to explain exactly why there is an increase for nitryfing bacteria, I deduced by the the 3 decrease's. They would decrease coz the dust blocks the sunlight decreasing the rate of photosynthesis, decreasing the energy produced and therefore affection all the food chain.

third question: I would have to draw a molecule of amylose and amylopection to explain that properly.

fourth question: that's a weird question coz im my opinion, B is also correct, but A makes more sense.

 

[Romeo10]

Please guys i want to know if i have to solve all the mcq questions in the question paper and then I copy the letters to the answer sheet or do I solve each question and then copy it to the answer sheet????
My exam is tomorrow !!!!!

 

[NinaCheng]

hey ppl can u pls help me with these
thanks in advance

O/N 04 q38 how do we get D
A square metre of grassland receives about 1 047 000 kJ of solar light energy each year.
The table shows what happens to this energy.
used in evaporation of water 523 500 kJ
transmitted to the ground 335 000 kJ
reflected by the leaves 165 000 kJ
used for growth 21 500 kJ
used for other life processes 1 500 kJ
respiratory heat losses 500 kJ
How much energy is used by the grass in photosynthesis?
A 2000 kJ B 19 500 kJ C 21 500 kJ D 23 500 kJ

Not sure about this one =/

O/N 07 q 39 ans is B
Following an environmental disaster of a major volcanic eruption, the atmosphere contains
greatly increased amounts of dust.
How does this affect the following organisms?
nitrifying bacteria primary consumer producer secondary consumer
A decrease increase increase increase
B increase decrease decrease decrease
C increase no change no change decrease
D no change increase decrease no change

due to dust, there'll be less sunlight reaching producers therefore cannot photosynthesise, results in decreased number of producers, hence affecting primary consumers who eat them and the secondary consumers who eat the primary consumers. so the only option which illustrates this is B

M/J 09
q7 ans is C
What is the general formula for starch?
A (C5H10O5)n B (C5H10O6)n C (C6H10O5)n D (C6H12O6)n

C because to get starch you condense alpha glucose together releasing water H20. So you minus 2h and 1o from the normal glucose formula and polymerise it, subscript n.

q34 ans is A but y not B
A graft of tissue, such as skin, from a different person is usually rejected by the body.
Which statement about graft rejection is correct?
A The graft is rejected by T-lymphocytes because they circulate in the blood and can gather at
the graft site.
B The graft is rejected by B-lymphocytes because they make and release antibodies which
react with the surface antigens on the graft cells.
C The graft is rejected by B-lymphocytes because T-lymphocytes are not stimulated to produce
antibodies.
D The graft is rejected by T-lymphocytes because the graft tissue causes T-lymphocytes to
release antibodies

for this question, because the graft is rejected, then it means that it has foreign antigens on it thus will be treated as a different cell. this is cell-mediated immunity therefore involves t lymphocytes. this leaves us with option A or D, since t lymphocytes dont secrete antibodies, A is the answer.

hope that helped =/ correct me if im wrong!

and good luck to everyone for the exam today~!

 

[ivorydale]

Please guys i want to know if i have to solve all the mcq questions in the question paper and then I copy the letters to the answer sheet or do I solve each question and then copy it to the answer sheet????
My exam is tomorrow !!!!!

you solve the question on the question paper but you have to mark it in the answer sheet provided.

 

[MidoTheHawk]

Please guys i want to know if i have to solve all the mcq questions in the question paper and then I copy the letters to the answer sheet or do I solve each question and then copy it to the answer sheet????
My exam is tomorrow !!!!!

As far as I know, You are not required to write anything in the question paper, yet you MUST highlight your selected answers on the answer sheet, provided.

 

[arsimme]

Which two structures when hydrolysed would release amino acids ?
a. protein channel and phospholipid.
b. lipid and carbohydrate chain.
c. protein channel and protein molecule.
d. carbohydrate chain and protein molecule.

 

[arsimme]

Skin for grafting can now be made by culturing living skin cells removed from a human patient. Tissue formed in this way is delicate and difficult to handle, though it can be strengthened by the incorporation of an additional material.
Which of the following would be the most suitable for reinforcing this mammalian tissue ?
a. albumen
b. collagen
c. fibrin
d. glycogen