meiosis is the cell division process that is responsible for the formation of gametes.
meiosis is the cell division process that is responsible for the formation of gametes.
what cell division process is responsible for the formation of gametes?
meiosis
cell division is the process by which a parent cell divides into two or more daughter cells. cell division usually occurs as part of a larger cell cycle. in eukaryotes, there are two distinct types of cell division: a vegetative division, whereby each daughter cell is genetically identical to the parent cell (mitosis), and a reproductive cell division, whereby the number of chromosomes in the daughter cells is reduced by half to produce haploid gametes (meiosis). meiosis results in four haploid daughter cells by undergoing one round of dna replication followed by two divisions. homologous chromosomes are separated in the first division, and sister chromatids are separated in the second division. both of these cell division cycles are used in the process of sexual reproduction at some point in their life cycle. both are believed to be present in the last eukaryotic common ancestor.
cell division
when cells are ready to divide, because cell size is big enough or because they receive the appropriate stimulus, they activate the mechanism to enter into the cell cycle, and they duplicate most organelles during s (synthesis) phase, including their centrosome. therefore, when the cell division process will end, each daughter cell will receive a complete set of organelles. at the same time, during s phase all cells must duplicate their dna very precisely, a process termed dna replication. once dna replication has finished, in eukaryotes the dna molecule is compacted and condensed, to form the mitotic chromosomes, each one constituted by two sister chromatids, which stay held together by the establishment of cohesion between them; each chromatid is a complete dna molecule, attached via microtubules to one of the two centrosomes of the dividing cell, located at opposed poles of the cell. the structure formed by the centrosomes and the microtubules is named mitotic spindle, due to its characteristic shape, holding the chromosomes between the two centrosomes. both sister chromatids stay together until anaphase; at this moment they separate from each other and they travel towards the centrosome to which they are attached. in this way, when the two daughter cells separate at the end of the division process, each one will receive a complete set of chromatids. the mechanism responsible for the correct distribution of sister chromatids during cell division is named chromosome segregation.
spindle checkpoint