Biology Paper 61 ANSWERS ARE HERE!!!!!

[ZainH]

Q1) (a) The cells in water gained water by osmosis down their water potential gradient and became turgid leading to firm cells. The cells in salt solution lost water by osmosis down their water potential gradient and became flaccid leading to soft and slimy cells. The cells in dry air did not gain/lose water (no osmosis/no net movement) as there was no water potential gradient.

(b) Improvements:
Repeat to reduce errors, use an accurate stop-watch, wider concentration of salts in salt solution and use surface area of leaf rather than it's length.

For the first part, Im pretty sure we didn't have to mention anything about the 3rd one since the question said to write what happened in the cells in which "Changes" took place.

 

[svenas]

1) label a black cell
2)yes colour darkness
3) It is a form of continuous variation.

I wrote for last one age difference, wat u thnk?

 

[Lujain M.]

I got it 70mm and magnification x14
I think I made it wrong like most of people & you did it right but not sure about it

I got the same answer..I hope it's correct though

 

[Lujain M.]

I think it is correct because it said the whole leaf not the inner part

 

[falehalsalem]

u guys u know for the insect question last part they asked what group do the other to above classify into can u say invertebrates because one was an earth worm and the other was a centipede

 

[Omar Hosny]

Hey guys I wrote in the improvements, repeat,same lengths of leaves, same specy,same age Correct ?

 

[Omar Hosny]

u guys u know for the insect question last part they asked what group do the other to above classify into can u say invertebrates because one was an earth worm and the other was a centipede

It's annelides bro and there was 'Clitellum'!

 

[Omar Hosny]

no but I thnk results will be more accurate ryt?

Stop watch is correct!!

 

[Omar Hosny]

i wrote continuous variation for the last one

Correct!

 

[Omar Hosny]

i dont understand what do u mean but for the mesophyll i labelled the black part in the middle.

i labelled that group of balls at the bottom lol :S

 

[svenas]

Correct!

ok I wrote for last answer age difference, is it correct???

 

[Omar Hosny]

ok I wrote for last answer age difference, is it correct???

i honestly don't know but i know some people who did something like that also!

 

[Lostsoul]

only frequency

But in the histogram you need to use the frequency deensity

 

[sweet life]

For the high and low concentration i wrote that low conc takes more time to change it's colour as compared to the high conc. Is it correct?

 

[Lostsoul]

For the first part, Im pretty sure we didn't have to mention anything about the 3rd one since the question said to write what happened in the cells in which "Changes" took place.

How about if for the improvements you say use a measuring cylinder to get accutate results, because an experiment is reliable only when it is accurate

 

[ZainH]

How about if for the improvements you say use a measuring cylinder to get accutate results, because an experiment is reliable only when it is accurate

I wrote repeat the experiment, and increase the duration of the final period.

 

[Lostsoul]

I wrote repeat the experiment, and increase the duration of the final period.

What do you think of my answer, well I mean your Bio teacher?

 

[kareem1997]

people for the improvements.... its dame easy... u can say keep the temperature constant since der r 2 strips in a solution.... and rather than jst comparing them by lookin at the shapes.... weight all three and based on there wights u can explain..... u can say repeat the experiment to get more visual results dats it

 

[Lostsoul]

I hear some people saying that they heated the test for Proteins.. I didn't, so who's wrong?