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Biology; Chemistry; Physics: Post your doubts here!

multixamza01

multixamza01

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french410 said:
i dont get the meaning of gametes
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Gametes are sex cells . They are produced in the sex organs , gonads .
Normally a cell has 46 chromosomes . But in gametes there are only 23 chromosomes. When the male gamete and female gamete combine , a zygote with 46 chromosomes is formed . 23 + 23 = 46 .

In plants, the male gamete is the pollen grain in the anthers and the female gamete is the ovum in the ovary .

In humans ( mammals ) the male gamete is the sperm produced in the testes , and the female gamete is the egg in the ovary .
 
Raikko

Raikko

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vaalaikumussalaam ........ i want pastpapers and marking schemes of biology from 2000 to 2010 plx provide these links for me.....before march 6........
 
Raikko

Raikko

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Durrani said:
how does CO2 harms the environment?
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CO2 - Otherwise called carbon dioxide effects our climate in many different ways. The way it works is that basically certain 'greenhouse gases' can't escape from our atmosphere because they get trapped. CO2 is what plants need to create oxygen etc. But when there is too much CO2 being admitted into our environment from burning fossil fuels, cars etc, and we are cutting down trees for paper - it is imbalanced and now it has started to catch up with us. a.k.a global warming. Because these gases are trapped in our atmosphere, they have more time to collect heat from our atmosphere and the sun - thus making our climate increase in heat. This then triggers ice caps to melt and floods to occur and then one day we will face a world with no more fresh water and many extinct animals who cannot survive in warm climates.

Carbon Dioxide would indirectly affect us by increasing global warming, melting the polar ice caps and flooding the world!
 
Raikko

Raikko

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boxfire1995 said:
Re: Biology,Chemistry & Physics Help Available Here !

sorry about mixing it up.... i was in a hurry.... and yes. i did get but i was a little stuck on a 87 past paper question.... so no biggie. =) thanx btw.
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plx can u find them for me its very important..............
 
Raikko

Raikko

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scouserlfc said:
Assalam-o-Allaikum and Hi everyone ,
hope u all are doin great !

Well as the topic says help for chemistry :D biology :D and Physics :D is available here that means that u can ask any mind blowing question or ask any question regarding a particular topic or ask abt any questions from Past paper or any of your text books. 8) :Yahoo!:

I made this topic so that people dont make many posts asking abt bio,physics or chemistry individually but they can post their reply here where it can be answered with ease and the members wont have to go searching for topics to help! :D !

So what are u waiting for now write ur questions here !
THANKS and Bye or Allah Hafiz ! :wink: :good:
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by my god allah im telling plx give me the links of 2000-2010 pastpaper questions and marking schemes.
i wish allah will bless u! insha allah! nd plx make it fast.... i wants these before march 6.. :(
 
Raikko

Raikko

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scouserlfc said:
Assalam-o-Allaikum and Hi everyone ,
hope u all are doin great !

Well as the topic says help for chemistry :D biology :D and Physics :D is available here that means that u can ask any mind blowing question or ask any question regarding a particular topic or ask abt any questions from Past paper or any of your text books. 8) :Yahoo!:

I made this topic so that people dont make many posts asking abt bio,physics or chemistry individually but they can post their reply here where it can be answered with ease and the members wont have to go searching for topics to help! :D !

So what are u waiting for now write ur questions here !
THANKS and Bye or Allah Hafiz ! :wink: :good:
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Assalam-o-Allaikum........... could u tell me these answers by your own plx.......5090/21/O/N/10.......Paper 2......Question number 1.....(c) (i), (ii)

GOD WILL BLESS U! insha allah!
 
Raikko

Raikko

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plx ans me 5090/21/O/N/10.......Paper 2......Question number 1.....(c) (i), (ii).........by your own
 
scouserlfc

scouserlfc

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Raikko said:
plx ans me 5090/21/O/N/10.......Paper 2......Question number 1.....(c) (i), (ii).........by your own
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Okay i havent checked the ms and im writing this answer from what i know :D

the flower shown there contains anthers and stigma of such a type that when anther is mature the stigma is not mature and is still developing,this as a result does not allow pollens from anther to pass into the stigma of the same flower but the insect has to help it in this process and when the stigma is mature as shown in the second figure the anthers have started to wear off !

Now for the part 2 the insect when only the anther is present is attracted by the nectar and when it reaches the flower the pollen grains from the mature anther stick to it and when it flies of to a nearby plant of the same species if the stigma there is mature the pollen grains stick onto the stigma and then pollination occurs while for stigma its the same process as i told but the insect comes to the flower with pollen grains stuck on it and then pollination occurs

I hope u get it :p
 
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