_mitosis Flashcards
Why does a cell need to divide?
asexual reproduction, repair wounds, grow body
What is chromatin?
A mass of DNA inside the nucleus
What happens to a cell when they’re ready to reproduce?
The chromatin gets tightly wound into chromosomes
How many chromosomes do humans have?
46
What is the cell cycle?
the cell’s life cycle
What 2 steps make up the cell cycle?
interphase and the mitotic phase
(preparation and division)
What 3 parts is interphase divided into?
G1 phase, S phase, G2 phase
What happens in the G1 phase?
the cell copies its organelles
What happens in the S phase?
the cell copies the DNA
What does the S phase stand for?
Synthesis phase
What happens to the # of chromosomes in the S phase?
although DNA changes, the # of chromosomes doesn’t change (chromosomes are counted by the # of centromeres)
What happens in the G2 phase?
The cell grows larger and copies important enzymes/proteins
What are sister chromatids?
The duplicated copies of stuck-together DNA
What happens in the mitotic phase?
One parent cell divides into 2 daughter cells
What are the steps of mitosis?
PMAT (prophase metaphase anaphase telophase)
What happens in prophase?
Chromatin condenses into chromosomes, the nuclear envelope disappears, centrosomes start to move toward the sides of the cell, and spindle fibers form
What happens in metaphase?
spindle fibers attach to the centromeres, and they move the chromosomes into the middle of the cell
What happens in anaphase?
sister chromatids are pulled apart by the spindle fibers, and they move towards opposite sides of the cell
What happens in telophase?
nuclear membrane reforms around chromosomes, membrane pinches in and forms down cell’s center, cells split apart
What can mistakes made during cell division lead to?
cancer and other disorders
