Question 40
Differentiate between the events of mitosis and meiosis.
Question 40
Differentiate between the events of mitosis and meiosis.
Mitotic cell division results into the increase in the number of cells that have same genetic composition whereas meiosis has its importance in the life cycle of sexually reproducing organisms.
MitosisMeiosisEventProphaseChrornomeres are not conspicuous.Chromomeres are quite conspicuous.Prophase is of shorter duration.Prophase− is of longer duration while prophase−II is very briefProphase is simpler and is hardlyProphase−I is complicated and is divisible into five substagesdistinguishable into substages.Prophase−IIis, however, very simpleEach chromosome has two distinct chromatidsChromosomes of prophase−I do not show distinct chromatidsNo bouquet stage is recordedChromosomes of animals and some plants show convergence towards one side during early prophase−I. It is known as bouquetstage.Chiasmata are absent.Chiasmata or visible connections between homologous chromosomes of bivalents are observed during diplotene, diakinesis (prophase−I) and metaphase−IMetaphase Centrorneres produce a singleA double metaphasic plate is formed by centromeresmetaphasic platein metaphase−I but only one in metaphase−IIChromosomes are independent andHomologous chromosomes are interconnected. Hence, the chromosomes occur in pairs ordo not show connections.bivalents in metaphase−I. They are however, free in metaphase−IIOnly the centromeres lie at the equator.Limbs of the chromosomes mostly lie at the equator whileThe limbs of chromosomes are oriented in various direction. the centromeres project towards the poles in metaphase−IA centromere is connected withA centromere is connected to one spindle pole in metaphase−I,both the spindle poles.but both in metaphase−IITwo chromatids of a chromosomeThe two chromatids of a chromosome are oftenare genetically similar.genetically different due to crossing overAnaphase A centromere splits length−wise to formCentromeres do not divide duringtwo centromeres in the beginning of anaphase.anaphase−I but do so in anaphase−IIAnaphasic chromosomes are single stranded.Chromosomes are double−stranded in anaphase−I, but single stranded in anaphase−II.Similar chromosomes move towardsDissimilar chromosomes move toward the oppositethe opposite poles in anaphasepoles both in anaphase−I and anaphase−IITelophaseTelophase is longer and producesTelophase−I is shorter and nuclei nowinterphase nucleienter the interphaseCytokinesisCytokinesis follows evey mitosis.Cytokinesis often does not occur after first or reductional division. It is thenIt produces two new cellssimultaneous after second division resulting in four new cells.
Mitotic cell division results into the increase in the number of cells that have same genetic composition whereas meiosis has its importance in the life cycle of sexually reproducing organisms.
MitosisMeiosisEventProphaseChrornomeres are not conspicuous.Chromomeres are quite conspicuous.Prophase is of shorter duration.Prophase− is of longer duration while prophase−II is very briefProphase is simpler and is hardlyProphase−I is complicated and is divisible into five substagesdistinguishable into substages.Prophase−IIis, however, very simpleEach chromosome has two distinct chromatidsChromosomes of prophase−I do not show distinct chromatidsNo bouquet stage is recordedChromosomes of animals and some plants show convergence towards one side during early prophase−I. It is known as bouquetstage.Chiasmata are absent.Chiasmata or visible connections between homologous chromosomes of bivalents are observed during diplotene, diakinesis (prophase−I) and metaphase−IMetaphase Centrorneres produce a singleA double metaphasic plate is formed by centromeresmetaphasic platein metaphase−I but only one in metaphase−IIChromosomes are independent andHomologous chromosomes are interconnected. Hence, the chromosomes occur in pairs ordo not show connections.bivalents in metaphase−I. They are however, free in metaphase−IIOnly the centromeres lie at the equator.Limbs of the chromosomes mostly lie at the equator whileThe limbs of chromosomes are oriented in various direction. the centromeres project towards the poles in metaphase−IA centromere is connected withA centromere is connected to one spindle pole in metaphase−I,both the spindle poles.but both in metaphase−IITwo chromatids of a chromosomeThe two chromatids of a chromosome are oftenare genetically similar.genetically different due to crossing overAnaphase A centromere splits length−wise to formCentromeres do not divide duringtwo centromeres in the beginning of anaphase.anaphase−I but do so in anaphase−IIAnaphasic chromosomes are single stranded.Chromosomes are double−stranded in anaphase−I, but single stranded in anaphase−II.Similar chromosomes move towardsDissimilar chromosomes move toward the oppositethe opposite poles in anaphasepoles both in anaphase−I and anaphase−IITelophaseTelophase is longer and producesTelophase−I is shorter and nuclei nowinterphase nucleienter the interphaseCytokinesisCytokinesis follows evey mitosis.Cytokinesis often does not occur after first or reductional division. It is thenIt produces two new cellssimultaneous after second division resulting in four new cells.
