vocabulary
What is a centriole
one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope.
what happens before cell divison
before cell division occurs, the cell replicates, or copies, all of its DNA
Name the main events of the cell cycle
G1, S, and G2
What is cancer
disorder in which some of the body cells lose the ability to control growth
What is mitosis
part of eukaryotic cell division during which cell nucleus divides
What is cell division
Process by which a cell divides into new daughter cells
How is cell DNA like the books in a library
this replication of DNA solves the problem of information storage because each daughter cell gets one complete set of genetic information. Thus, each daughter cell receives its own genetic "library"
Describe what happens during each of the four phases of mitosis
During prophase, the chromosomes become visible. During metaphase, the chromosomes line up across the center of the cell. During anaphase, the centromeres that join the sister chromatids split, allowing the sister chromatids to separate and become individual chromosomes. In telophase, the chromosomes, which were distinct and condensed, begin to disperse into a tangle of dense material.
What happens when cells do not respond to the signals that normally regulate there growth
they divide uncontrollably
what is prophase
first and longest phase of mitosis, during which the chromosomes become visible and centrioles separate and take up positions on the opposite sidesnof the nucleus
what is chromatid
one of the two identical "sister" parts of duplicated chromosome
As a cell increases in size, which increases more rapidly, its surface area or its volume
each daughter cell has an increased ratio of surface area to volume
Describe what happens during interphase
an in between period of growth in the cell cycle
how do cells respond to contact with other cells
when cells come into contact with other cells, they respond by not growing
second phase of mitosis, during which the chromosomes line up across the center of the cell
what is a centromere
area where the chromatids of chromosome are attached
Give two reasons why cells divide
replication of DNA solves the problem of information storage because each daughter cell gets one complete set genetics information. Cell division also solves the problem of increasing size by reducing cell volume
what are chromosomes made of
Chromosomes are made up of DNA, which carries the cells coded genetics information, and proteins
why can cancer be considered a disease of the cell cycle
What is anaphase
the third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles
what is a spindle
fanlike microtubule structure that helps separate the chromosomes during mitosis
What happens before a cell becomes too large
before it becomes too large, a growing cell divides forming two daughter cells
How do prokaryotic cells divide
in most of prokaryotic, the rest of the process of cell division is a simple matter of separating the contents of the cell into two parts
what chemicals regulate the cell cycle and how do they work
cyclins, internal regulators allow the cell cycle to proceed only when certain processes have happened inside the cell. External regulators direct cells to speed up or slow down the cell cycle
what is telophase
fourth and final phase of mitosis, during which the chromosomes begin to disperse into a tangle of dense material