Chapter 16 Flashcards
Cell division
Reproduction of cells
2 types of cell division
Mitosis
Meiosis
Cytogenetic
Find of genetics involving microscopic examination of chromosomes & cell division
Karyotype
Reveals number, size, & form of chromosomes in an actively dividing cell
How many pairs of chromosomes in human
23
Total howmany chromosomes in human
46
How many sex chromosomes in human
1 pair
How many autonomies in human
22 pair
Diploid or 2n
Humans have 23 pairs of chromosomes
Haploid or N
Gametes have 1 member of each pair of chromosomes or 23 total chromosomes
Cell cycle
Sequence of event/phases resulting in 2 daughter cells
G1
First gap
S
Synthesis/copy of DNA
G2
Second gap
M
Mitosis & cytokinesis
G0
Substitute for g1 for cells postponing division of never dividing again
G1 Interphase
Cell accumulates molecular changes that cause progression through the cell cycle
Phase restriction point for g1 interphase
Where cell committed to enter phase
S interphase
Chromosomes replicate, & after replication 2 copies stay joined to each other & ape called sister chromatids
What comes after S
G2
How many chromatids in g2
92 total/46 pairs
G2 interpahse
Cell synthesizes proteins needed during mitosis & cytokinesis
M phase - mitosis
Divide 1 cell nucleus into 2
Cytokinesis
Division of cytoplasm,
Decision to divide relies
External factors
Internal factors
External factors
Environmental condition
Internal factors
Cell cycle control molecules
Cell cycle Control
Cyclins or cyclin- dependent kinases
3 critical regulatory checkpoints
G1 checkpoint
G2 check point
Metaphase checkpoint
G1 checkpoint
Senses DNA damage, conditions favorable for division
G2 checkpoint
Senses DNA damage, proper replication, proteins for transition to M are present
Metaphase checkpoint
Integrity of spindle apparats (chromosome sorting)
Mitotic cell division
A cell divides to produce 2 new cell genetically identical to the original
What is original cell called
Mother cells.