6.7 production of haploid gametes

what is a gamete?

* the reproductive cell (sprem + egg)
* number of chromosomes in gametes is haploid number

what is division?

* production of gametes via cellular division in meiosis I → reduces chromosome number from diploid to haploid

what is sexual reproduction?

* relies on meiosis
* halves chromosome number to produce gametes
* offsprings genetics are different to parents + each others

what is asexual reproduction?

* cellular process (mitosis)
* reproduces an exact copy of genetic information
* single parent cell → two daughter cells

what is meiosis?

* a type of cell division that produces haploid gametes
* 1/2 the number present in stomatic cells
* diploid is restored after fertilisation

what is crossing over?

crossing over occurs in prophase I

1)homologous chromosomes become connected (bivalent)

2) connected non-sister chromatids become entangled

3) DNA breaks and recombines

4) new combinations of alleles form along the length of chromatids

what is independant assortment?

the formation of random chromosome combinations. pairs of alleles separate independently during metaphase I. homologous chromosomes line up in the middle.

what represents the combos/outcomes?

2^n → n = no. of chromosome pairs

why is sexual reproduction good?

meiosis produces sex cells with infinite variation which allows for genetic diversity. sexual reproduction allows species to adapt to changing environment