Flashcards in Cellular Replication/Division Deck (27)
Mitosis is new cells or copies of cells?
Copies. The same thing over & over.
Meiosis is copies of a cell or new cells?
New cells. "sex cells"
Every cell has part of the old & part new
What are Genes?
Sequences of nucleotides that code for specific products.
What are Chromosomes?
Collections of genes in a single larger structure.
What are Chromatin?
Complex of DNA w/ protein.
What are Euchromatin?
Lightly packed ends of a chromosome
What are Heterochromatin?
Heavily packed ends of a chromosome
What are Telomeres ?
they protect your dna & prevent from loss during the replication.
What is a Centromere ?
What is a Haploid?
1 copy of each gene
What is a Diploid?
2 copies of each gene
What is a Polyploid ?
Multiple copies of genes.
What is interphase?
A preparation for the events to come, not technically part of mitosis or meiosis.
What are the 4 parts of Interphase?
G0 - Gap 0
G1 - Gap 1
S - Synthesis
G2 - Gap 2
What is G0?
not actively replicating
cells can come & go
some cells never leave
nerve cells in the spine
sensory cells in the ear
What is G1?
Organelles will double in #'s
cell grows to be much larger in size
stock pile materials
check point of cell health
-is the cell healthy/fit to divide?
-will the environment support it?
What is S Synthesis?
making a 2nd copy
extreme point of vulnrability
genome is not usable during this process
beyond this point the cell can not back out
What is G2?
Setting up for the machinery for mitosis and meiosis
produces extra proteins
check point for DNA integrity
DNA was copied correctly & has no glaring problems
What is the outcome of Mitosis?
2 Identical cells, Diploid cells.
What is the outcome of Meiosis?
4 non identical cells, Haploid cells.
What happens in Prophase?
Centrioles move toward opposite poles
symmetrically divide the cell
nuclear membrane breaks up.
What happens in Metaphase?
Centrioles arrive at opposite poles.
extend spindle fibers across the cell.
chromosomes align at the metaphysical line (mid line)
What is the Anaphase?
Spindle fibers shorten
pulls sister chromatids to opposite poles
What happens in Telophase?
nuclear membrane reforms
DNA becomes less condensed.
What is Cytokinesis?
Splitting of the cell body.
What is non dysjunction?
in meiosis failure to properly separate chromatids during anaphase
too many chromosomes or too few chromosomes