Mitosis and Meiosis

Mitosis

100

Prophase

chromatin fibers condense, the nucleolus disappears and the nuclear envelope breaks down, spindle forms

200

Metaphase

Chromosomes align along the middle of the cell, spindle fibers attached to chromosomes

300

Anaphase

sister chromatids separate, spindle fibers pull the chromatids to the poles of the cell

400

Telophase

chromosomes reach the poles of the cell, spindle fibers disappear, the nuclear envelope reforms around the two new nuclei, and the chromosomes uncoil and lengthen

500

Cytokinesis

Completes cell division process by dividing cytoplasm into 2 new cells

Meiosis

100

Prophase

two pairs of homologous chromosomes stick together and form tetrads, tetrads exchange genetic material through crossing over

200

Metaphase

chromosomes align along middle of cell

300

Anaphase

sister chromatids separate and move to poles of cell

400

Telophase

Chromosomes reach poles of cell

500

Cytokinesis

Completes the cell division process by dividing cytoplasm into 2 new cells

Interphase

100

Interphase

prior to meiosis 1/mitosis; cell grows, duplicates chromosomes, and checks system to prepare for division

200

Gap 1

cell grows, produces protein

300

Synthesis

DNA duplication/replication

400

Gap 2

cell continues to grow, produces protein, prepares for division

500

Time spent in phase

as much as 90% (most of their time is spent in this phase)

DNA

100

Cancer

a disease caused by severe disruption in the mechanisms that control the cell cycle, leading to uncontrolled cell division

200

difference in tumor types

benign: an abnormal mass of normal cells, always remain in original site

malignant: masses of cells resulting from cancer cell reproduction, can metastasis or spread to other parts of the body

300

Crossing Over

exchange of genetic material; homologous chromosomes are closely paired all along their lengths; precise gene-by-gene alignment between adjacent chromatids of the chromosomes (segments can be exchanged at one or more sites)

400

Genetic Recombination

After crossing over, a single chromosome that contains genetic information from both parents is produced

500

checkpoints in the cell

Gap 1, Gap 2, Metaphase

Definitions

100

chromatin

combination of DNA and protein molecules, in the form of long, thin fibers, making up the genetic material in the nucleus of a eukaryotic cell

200

centromere

region where two sister chromatids are joined tightly together

300

centrosome

region of cytoplasmic material that in animal cells contains structures called centrioles

400

homologous chromosomes

one of a matching pair of chromosomes, one inherited from each parent

500

sister chromatids

one of a pair of identical chromosomes created before a cell divides