levels of the cell
define organism
one individual member of a species
define external
signals that come from OUTSIDE of the cell
what is cancer?
uncontrolled cell division
how often do cells divide?
every cell divides at a different rate based on its need
define chromatid
one half of a duplicated chromosome
define Organ System
set of organs working together for a common function
what are checkpoints?
critical point where "stop" & "go" signals can regulate the cell
define malignant
cancer cells that breakaway from the tumor and move to other parts of the body --> more tumors
describe cytokinesis in animal cells
forms a cleavage furrow that pinches the cell into 2 equal parts
define centromere
region of the condensed chromosomes that looked pinched
define organ
set of tissues working together for a common function
what is apoptosis?
programmed cell death
define benign
Abnormal cells typically remain clustered together
describe cytokinesis in plant cells
cell plate forms midway between divided nuclei and gradually develops into a membrane
define chromosome
one long continuous thread of DNA that consists of thousands of genes and regulatory information
define tissue
group of cells working together for a common function
define internal
signals that come from the cell's own nucleus
what is carcinogens?
cancer causing agents; chemicals that cause cancer by mutating DNA
define mitosis
the division phase of the cell cycle
-1 cell becomes 2 identical daughter cells
define Telomere
ends of the DNA molecule
define cell
most basic unit of life that has all the characteristics of life
what is the cell cycle controlled by?
cell cycle is controlled by a chemical control system that starts and stops in the cell cycle
what are some causes of cancer?
biological factors, lifestyle choices, viruses and other infections, and exposure to carcinogens
what is the end result of cytokinesis?
2 identical body cells
define sister chromatids
two identical chromatids