Fundamentals of Anatomy and Physiology

84 Chapter 4

MITOSIS

Prophase Metaphase Anaphase Telophase Daughter cells

Chromosomes con- Microtubule Sister chromatids Chromatids arrive Cell division com-

dense. Spindle spindle apparatus separate and at each pole, and plete. Each cell

fibers form attaches to move to opposite new nuclear mem- receives chromo-

between centri- chromosomes. poles. branes form. Cell somes that are

oles which move Chromosomes division begins. identical to those

toward opposite align along spindle in original nucleus.

poles.^ equator.^

MEIOSIS I

Prophase I Metaphase I Anaphase I Telophase I Daughter cells

Homologous Microtubule Homologous pairs One set of paired Each cell receives

chromosomes spindle apparatus of chromosomes chromosomes exchanged

further condense attaches to separate and arrives at each chromosomal

and pair. Crossing- chromosomes. move to opposite pole, and nuclear material from

over occurs. Homologous pairs poles. division begins. homologous

Spindle fibers align along spindle Centromeres do chromosomes.

form between equator. not divide.

centrioles which

move toward

opposite poles.

MEIOSIS II

Prophase II Metaphase II Anaphase II Telophase II Daughter cells

Chromosomes re- Microtubule Sister chromatids Chromatids arrive Cell division com-

condense. Spindle spindle apparatus separate and at each pole, and plete. Each cell

fibers form between attaches to move to opposite cell division ends up with half

centrioles which chromosomes. poles. begins. the original number

move toward Chromosomes Centromeres of chromosomes.

opposite poles.^ align along spindle.^ divide.^

Figure 4- 17 A comparison of mitosis and meiosis.

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