The Cell Cycle

prophase I

crossing over occurs. homologous pairs have one or more X-shaped regions called chiasmata.

metaphase I

pairs of homologous chromosomes arrange at the metaphase plate.

anaphase I

homologous chromosomes separate, while sister chromatids remain attached at the centromere

interphase

the phase of the cell cycle where the cell grows, carries out its normal functions, and prepares for division.

G1

the first gap phase of interphase during which the cell grows and carries out its normal functions.

S

the synthesis phase of interphase during which DNA is replicated, resulting in duplicated chromosomes.

G2

the second gap phase of interphase during which the cell continues to grow and prepares for mitosis.

mitosis

the process of cell division in which a single cell divides into two genetically identical daughter cells.

prophase

the stage of mitosis during which chromosomes condense, the nuclear envelope breaks down, and spindle fibers begin to form.

prometaphase

the stage of mitosis during which the nuclear envelope fragments, and kinetochores form at the centromeres of each chromatid.

metaphase

the stage of mitosis during which chromosomes line up along the metaphase plate at the center of the cell.

anaphase

the stage of mitosis during which sister chromatids separate and are pulled toward opposite poles of the cell by spindle fibers.

telophase

the stage of mitosis during which two daughter nuclei form, nucleoli reappear, and chromosomes begin to decondense

cytokinesis

the process of cytoplasmic division following mitosis or meiosis, resulting in the formation of two daughter cells.

cleavage furrow

a contractile ring composed of actin and myosin filaments that forms during cytokinesis in animal cells, pinching the cell membrane inward to separate the daughter cells.

cell plate

a structure that forms during cytokinesis in plant cells, eventually developing into the cell wall that separates the two daughter cells.

mitotic spindle

a structure composed of microtubules that separates chromosomes into daughter cells

centrosome

regions in animal cells that organize the microtubules of the spindle

kinetochore

a protein structure located at the centromere of each chromatid during cell division.

chiasmata

X-shaped regions in homologous pairs during Prophase I

synapsis

pairing of homologous chromosomes during prophase I of meiosis

crossing over

exchange of genetic material during prophase I