cell reproduction Flashcards
4 main stages of cell cycle
G1 (gap 1) phase, S phase (synthesis), G2 (gap 2) phase, M phase (mitosis)
what occurs in G1 phase
cell does its normal function, cell grows/increases size, organelles increase in #, cell undergoes checkpoints to make sure it is ready for next stage, preps to replicate DNA
what occurs in S phase
a full copy of DNA is being made
what occurs in G2
norm func, growth, checkpoints to make sure everything is in order, preps for division
what occurs in M phase
division of cell nucleus separating DNA (mitosis), division of cytoplasm (cytokinesis), M phase is NOT the actual phase of mitosis
when is a cell regulated during the cycle
G1-S checkpoint, G2 -M checkpoint
what is the importance of cell cycle checkpoints
highly regulates cell life cycle
what happens if a cell is not checked/regulated?
it can lead to uncontrolled cell division, too many/few cells, that can lead to the development of a tumor/wart (too many) or hair loss(too few)
what is a chromosome
package of DNA, has centromere and chromatids
why do cells need to divide
for growth, development, reproduction, and repair of damaged tissues to replace old/dying cells
4 phases of mitosis
prophase, metaphase, anaphase, telophase
purpose of mitosis
for growth (mainly in children) and in response to injuries or cell death
what cells are produced from mitosis
2 identical daughter cells
what occurs during cytokinesis
division of cytoplasm, begins during end of anaphase and finishes during telophase/mitosis, two identical daughter cells are made
What is the difference between cytokinesis in plants and animals
animal- membrane pinches closed like a drawstring
Plant-cell plate forms, cells cannot pinch inward due to cell wall
what are regulatory checkpoints
molecular and physical checkpoints
how is a cell at rest identified in the cell cycle?
Interphase
what is the importance of cell cycle checkpoints
Makes sure everything is in order, makes sure cells meet certain criterias
What happens if there are mutations in the proteins that control these proteins
loss of inhibition, loss of function, development of cancer/tumors
what is cancer and how does it relate to cells
cancer is uncontrolled division of calls, results from an improperly regulated cell cycle, too much cell division or too little cell death
what are features of a cancer cells that are different than healthy cells
cancer cells- resistant to cell death (apoptosis), divide uncontrollably, irregular shape
healthy- divide and die regularly, all have similar shape
how does the rate of cell division in healthy cells compare to cancer cells
cancer cells have uncontrollable cell division, leading to too few/many cells. healthy cells only divide when they receive signals
purpose of the M phase in a cell cycle, why do cells need to divide
division of nucleus (mit) and cytoplasm (cytoken), cells need to divide for growth and repair based on what the body needs
why do cells undergo apoptosis
eliminates unnecessary cells during development, removes unhealthy/damaged cells in mature organism
function of cell cycle regulators
molecular signals that may stimulate/halt cell division, instructs cells to differentiate, initiates cell death
Interphase
Time during which cell grows and matures. Consists of Gap 1, Synthesis, and Gap 2 stages
prophase
Nuclear membrane disappears. Chromatin condenses to form chromosomes
metaphase
Chromosomes line up along the equator of the cell
anaphase
Sister chromatids are pulled to opposite poles of the cell
telophase
Nuclear membrane forms around each full set of chromosomes. Chromosomes become chromatin
cytokinesis
Cytoplasm divides resulting in formation of two daughter cells
mitosis stages in order
PMAT, cytokinesis
what are chromosomes made up of
chromatin
why is it important cells duplicate DNA before cell division
so each new cell gets a full set of DNA
if 15 chromosomes (2 chromatids with centromere) split, at the end of cytokinesis how many chromosomes are in each cell
15
what are the 2 type of genes associated with each of the cell cycle regulators
proto-oncogenes, tumor suppressor genes
what are the mutated version of proto-oncogenes? what do they do
oncogenes- increases stimulated movement in a cell, leads to uncontrollable cell divison
what do mutated tumor suppressor genes do?
loss of inhibition, increasing movement and uncontrollable cell division
