Meiosis As Flashcards
define meiosis
makes 4 daughter cells (gametes) haploid cells (half the number of chromosomes of parents
what is the importance of meiosis
it halves the number of chromosomes
diploid number is restored in fertilisation
introduces variation through crossing over and independent segregation of chromosomes
differences between mitosis and meiosis
chromosome number remains the same / cells produced diploid in mitosis
chromosome number halved in meiosis
cells produced identical in mitosis not in meiosis
mitosis is 1 division and 2 cell meiosis is 2 divisions and 4 cells
mitosis is used in body cell formation meiosis in gamete formation
in meiosis or mitosis does the chromosome number stay the same
mitosis
in meiosis or mitosis are the cells produced diploid
mitosis
in meiosis or mitosis does the chromosome number half
meiosis
in meiosis or mitosis are the cells produced haploid
meiosis
in meiosis or mitosis are the cells produced identical
mitosis
in meiosis or mitosis are the cells produced non identical
meiosis
in meiosis or mitosis is there only on division
mitosis
in meiosis or mitosis are two cells produced
mitosis
in meiosis or mitosis is there two divisions
meiosis
in meiosis or mitosis are four cells produced
meiosis
is mitosis or meiosis used for body cell formation
mitosis
is mitosis or meiosis used in gamete formation
meiosis
define non disjunction meiosis
can lead to mutations in the number of chromosomes
define polyploidy
changes in the whole sets of chromosomes
organisms have 3 or more sets of chromosomes
define meiosis 2
like mitosis except starts with cells with half the number of chromosome
ends with gametes
define meiosis 1
like mitosis except chromosomes line up in homologous pairs in metaphase
define homologous pairs
2 chromosomes together that carry the same genes
what happens during meiosis 1 in anaphase
chromosomes are pulled to opposite poles of cell
what happens during independent segregation
maternal and paternal chromosomes are reshuffled in and combination
what happens during crossing over
chromatids get twisted and exchange alleles between homologous chromosomes producing a new combination of alleles
what creates variation in meiosis
crossing over
independent segregation
what is the formula to work out the number of possible combinations of chromosomes for each daughter cell
2^n where n is the number of pairs of homologous chromosomes
what is the formula for the number of possible combinations made from the fertilisation of 2 gametes from separate individuals
(2^n)^2 where n is the number of homologous chromosomes
