Question

if the organism is haploid does it mean meiosis never occur in the organism

Answer 1

I think you are correct - there is a rare disorder in which the individual has only haploid cells after the first cell division. These individuals are unable to reproduce, probably because meiosis doesn't work. It's mentioned in the following page:

http://en.wikipedia.org/wiki/Ploidy

Answer 2

Sorry, I forgot to mention the name of the rare disorder: Deterimental Haploidy Syndrome

Answer 3

Not necessarily. Some organisms are considered haploid because the only diploid stage they have is the zygote. Meiosis occurs directly after fertilisation (or at best, after a dormant phase in which the zygote just sits there and waits for conditions to improve).

http://upload.wikimedia.org/wikipedia/commons/7/7f/Zygotic_meiosis.png

Remember that humans are considered diploid even though we have haploid gametes.

Answer 4

thats y i m lil bit confuse as we say zygote is always dipoloid and if the organim is haploid i gues ans should be yes as in lifecycle of organism meiosis is not occuring but if the organim i haploid den it is occuring at the stage of embryony but if i write embyonic stage itself it reveals dat in organism at once the meiosis occur :'( this is the qn of my book and i m nt getting a single clue what to write :(

Answer 5

I don't think so...

Answer 6

:'( @blues

Answer 7

I remembered that the meiosis didn't occur only when the number of genome is odd....

Answer 8

but its a organism mean it will form zygote too right and zygote is diploid

Answer 9

so i think you are talking about the phenomenon aspermous watermelon..It happens because the number of genome is odd..and on the other hand..zigote is not diploid..ovum is..

Answer 10

I didn't get you ...which part you didn't get?

Answer 11

zygote is diploid its an universal fact and i m nt getting whether to say yes or no to the qn

Answer 12

I suppose it depends on what you mean by "organism". If you're talking about one haploid individual organism, then meiosis will NOT occur in that individual. If you're talking about a species (i.e. a type of organism), then meiosis may well occur as part of an alternation of generations, even if the species is predominantly haploid.