Biology; Chemistry; Physics: Post your doubts here!

[AhsanAfzal]

no it is also used on plant cells so we can see chloroplasts through microscopes

 

[AhsanAfzal]

i have edited it

 

[chocolate_girl]

iodine isnt it only necesarry for starch???

No like when we use it for slide, dont we??

 

[chocolate_girl]

no it is also used on plant cells so we can see chloroplasts through microscopes

Oh alryt. Do we use water like on slide to stick nythng on it better?

 

[shehri]

someone post the steps for carrying out an experiment to observe cell, general point which have to be used for every eperiment!

 

[chocolate_girl]

someone post the steps for carrying out an experiment to observe cell, general point which have to be used for every eperiment!

Prepare slide by putting on its centre whatever is to b observed. Cover carefully with coverslip at an angle to avoid air bubbles. Put on microscope stage and adjust clips to fix it in position. Examine first under low power then under high power. Describe your observation( you may draw a diagram as well).

 

[AhsanAfzal]

Oh alryt. Do we use water like on slide to stick nythng on it better?

Usually we put the specimen in a few drops of water so that it does not dry out whilst we are looking at it. The water also helps the light to pass through the specimen more evenly.

 

[asma tareen]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s10_qp_62.pdf
Q1 a last part
Q1 d
plzz help

 

[AhsanAfzal]

1a when a bee sits pollen sticks to it and the bee takes it too another flower's stigma.
1d each food is lighted with a match. the one which increases the temp of water the most has the highest energy content. safety=wear googles.

 

[asma tareen]

1a when a bee sits pollen sticks to it and the bee takes it too another flower's stigma.
1d each food is lighted with a match. the one which increases the temp of water the most has the highest energy content. safety=wear googles.

thnx dude

 

[shehri]

1. Q1-a , insect pollination, the plant is a lupin speicemen, bees come to collect pollen for there hives, when a bee lands on the flower, the pollen slides on the kneel of the petals, the stigma pushes the pollen grains on the the legs of the leaf, the bee visits some other plant, if it has already lost its pollen, only the stigma will come out, the pollen will stick to the stigma..

 

[asma tareen]

1. Q1-a , insect pollination, the plant is a lupin speicemen, bees come to collect pollen for there hives, when a bee lands on the flower, the pollen slides on the kneel of the petals, the stigma pushes the pollen grains on the the legs of the leaf, the bee visits some other plant, if it has already lost its pollen, only the stigma will come out, the pollen will stick to the stigma..

thnx

 

[asma tareen]

how wud we do Q3 a i and ii

 

[Khadija_1234]

If the specimen already has a magnification of x0.75
And we're asked to draw and find the magnification of our drawing and the length of the specimen is 3.5 cm and the length of my drawing in 7.8cm then will I find the magnification like this? 78/35 into 0.75

 

[asma tareen]

do we always need to mark the scale from 0 or we can start with a larger number???
plxxxx reply quick anyone

 

[asma tareen]

do we always need to mark the scale from 0 or we can start with a larger number???
plxxxx reply quick anyone

 

[Snowysangel]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s11_qp_61.pdf
Q1 B part, can someone tell me the name of any plant tissue and also what is external blotting of a tissure? plis reply asap

You'd have to use a small piece of the tissue. You could use a potato, but I'd go for a softer,easily removable plant tissue [like onion epidermis]. External blotting helps dry the tissues up, for fair testing

 

[Snowysangel]

oops sorry i had to write radicle
apologies

Wait I don't get where the radicle and plumule are located in that we'd :s are they the structures in the middle?

 

[asma tareen]

Wait I don't get where the radicle and plumule are located in that we'd :s are they the structures in the middle?

thats what we are searching fr

 

[Ahmed Alaa El-shamy]

did u get the answer? cux i m stuck at the same question :/

Yea just half of the answer : Use a microscope to observe the Yest cells using a high magnification, place yeast cells on a cell counter and stain them to make them visible. ( well i guess that answers almost more than half of the question) what is missing now is to know how to estimate their total population! Any helpful suggestions ?