Qualification > Sciences
IGCSE Biology Paper 3
girl_92:
--- Quote from: hash094 on June 09, 2009, 01:08:17 pm ---because Africa is affected by malaria also and malaria's virus need oxygen to reproduce in body, so ppl with sickle cell anemia have less oxygen in the re blood cell thus virus cant reproduce and they survive from malaria,hence this remains in generation!!!
simple!
;) ;)
--- End quote ---
i rote tht only ppl who are heterozygous tend to survive hence the population tends to develop sickle shaped rbcs n only those who r heterozygous survives n according to natural selection only the organism which is welll adapted to its surroundings can survive so this one way of adaptation
am i correctin nyway plz temme ???
hdbkiwi:
--- Quote from: hash094 on June 09, 2009, 01:08:17 pm ---because Africa is affected by malaria also and malaria's virus need oxygen to reproduce in body, so ppl with sickle cell anemia have less oxygen in the re blood cell thus virus cant reproduce and they survive from malaria,hence this remains in generation!!!
simple!
;) ;)
--- End quote ---
Umm plasmodium doesn't need oxygen to undergo sexual reproduction I thought?
What (I hope its right :) ) happens is that a mosquito carrying the plasmodium pathogen (that causes malaria) bites someone with sickle cell aneamia, and a normal person-the normal person gets malaria and dies-the sickle cell person does not, as they have resistance to it(I don't think you need to write why they have the resistance) Thus, more 'normal' people die, sickle people survive, so natural selection has occured and the sickle people breed and then produce more sickle people, so pop of them increases :)
girl_92:
--- Quote from: hdbkiwi on June 09, 2009, 01:10:23 pm ---Please stick to english so everyone can understand :)
It was a nutural selection question madee
--- End quote ---
yup
°o.O-hash94-O.o°:
--- Quote from: madee on June 09, 2009, 01:12:54 pm ---
--- Quote from: hash094 on June 09, 2009, 01:08:17 pm ---because Africa is affected by malaria also and malaria's virus need oxygen to reproduce in body, so ppl with sickle cell anemia have less oxygen in the re blood cell thus virus cant reproduce and they survive from malaria,hence this remains in generation!!!
simple!
;) ;)
--- End quote ---
i rote tht only ppl who are heterozygous tend to survive hence the population tends to develop sickle shaped rbcs n only those who r heterozygous survives n according to natural selection only the organism which is welll adapted to its surroundings can survive so this one way of adaptation
am i correctin nyway plz temme ???
--- End quote ---
i think u r right!
hdbkiwi:
--- Quote from: madee on June 09, 2009, 01:13:34 pm ---
--- Quote from: hdbkiwi on June 09, 2009, 01:10:23 pm ---Please stick to english so everyone can understand :)
It was a nutural selection question madee
--- End quote ---
yup
--- End quote ---
thanks hehe
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