Biology; Chemistry; Physics: Post your doubts here!

[chocolate_girl]

Iodine has a very quick reaction so colour will immediately change to black. Orange will also be correct. Read the Examiner Report for more clarification.

Thankyou

 

[passion hunter]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s08_qp_6.pdf please someone tell me how to calculate surface area of given cubes in question no.1 part a.

1st cube...all six sides exposed...1cm x 6. = 6.....2nd cube has been cut into eight pieces.... area of each side of one block 0.5x0.5 = 0.25......0.25x 6sides= 1.5...total 8 blocks so 8x1.5= 12......3rd cube has been cut into two equal pieces...... dimensions of one block are now 1x1x0.5.....upper part and base is 1cmx1cm so 1x 2 sides=2cm....the other 4 sides are 0.5x1....so 4(1xo.5)..=2cm.....total area of one cube =4 and 2 cubes =8......

 

[passion hunter]

If we decrease the distance on the left side by moving the screw in, the perpendicular distance on that side will be decreased..Now as may know that moment is directly proportional to the perpendicular distance the moment on the left side is lesser so left side goes up and the flattened end goes down..
Hope u got it..

i know what you are trying to say but perpendicular distance will not matter unless there is equal force on both sides.....

 

[passion hunter]

thanku soo much. it helped alot.

no problem

 

[Hskk]

ahan but thn what abt total poppulation any idea
"

Note the volume of the yeast used to make the slide and count the number of cells in that particular volume which are visible in the microscope. Multiply that by the total volume of yeast in the exp.

 

[chocolate_girl]

1st cube...all six sides exposed...1cm x 6. = 6.....2nd cube has been cut into eight pieces.... area of each side of one block 0.5x0.5 = 0.25......0.25x 6sides= 1.5...total 8 blocks so 8x1.5= 12......3rd cube has been cut into two equal pieces...... dimensions of one block are now 1x1x0.5.....upper part and base is 1cmx1cm so 1x 2 sides=2cm....the other 4 sides are 0.5x1....so 4(1xo.5)..=2cm.....total area of one cube =4 and 2 cubes =8......

Alright so we have to take all sides of each cube not just the sides exposed?

 

[passion hunter]

Alright so we have to take all sides of each cube not just the sides exposed?

all of the sides will be exposed obviously

 

[tweetie]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Biology (0610)/0610_s10_qp_62.pdf
q3-d please help asap

 

[robinhoodmustafa]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Biology (0610)/0610_s10_qp_62.pdf
q3-d please help asap

Penicillin is used to treat very many different types of infections that are caused by bacteria. Penicillin is an antibiotic that works by killing the bacteria.

 

[Iridescent]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Biology (0610)/0610_s10_qp_62.pdf
q3-d please help asap

The antibiotic stop the bacteria from forming their cell wall. Therefore, bacteria do not grow and reproduce and die eventually. It can be used to treat humans because human cells do not have cell wall. Therefore, the antibiotic cannot harm the human body cells.

 

[Kamihus]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s11_qp_12.pdf
Q#1 I know the answer but what are 4 and 5 and which is the vacoule

 

[Iridescent]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s11_qp_12.pdf
Q#1 I know the answer but what are 4 and 5 and which is the vacoule

4 looks like its the nucleus and 5 seems to be the vacuole.

 

[farhan141]

4 looks like its the nucleus and 5 seems to be the vacuole.

Yes because the nucleolus can be seen in 4

 

[Khadija_1234]

In ATPs if the points plotted on the graph are in the form of an uneven curve, we can simply join them with a rule right?

 

[chocolate_girl]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s12_qp_61.pdf
Someone please answer the very last question of this paper

 

[ahmed rockstar]

can someone pllzz post a link of biology notes for preparation of p6

 

[Iridescent]

can someone pllzz post a link of biology notes for preparation of p6

https://www.xtremepapers.com/community/threads/biology-pp6-revision-notes.25151/unread
http://www.mediafire.com/download.php?fd5s1c9s6z6a8n3

 

[chocolate_girl]

Is water added at the end of ethanol emulsion test for fats and if so then why it is added?

 

[fatima0000]

i wanna confirm that:
=> lymphocytes secrete antibodies or phgocytes do?

 

[chocolate_girl]

i wanna confirm that:
=> lymphocytes secrete antibodies or phgocytes do?

Lymphocytes