centromere
area of attachment between two sister chromatids
Kinetochores
structures of proteins and specific sections of chromosomal DNA at the centromere;
point of attachment of duplicated chromosome
Chromatids
Two copies of duplicated chromosome
Spindle Apparatus
formed from microtubules extending from two centromeres; as centrosomes move way
from each other the microtubules lengthen
to see if DNA is damaged
What is the G1 checkpoint for?
to check to see if DNA is replicated properly
What is the G2 checkpoint for?
spindle assembly checkpoint, checks for alignment of the chromosomes
What is the M checkpoint for?
Synthesis of cell components increase in the number of organelles
What occurs in G1 phase of interphase?
synthesis (replication) of DNA; doubling genetic material
What occurs in S phase of interphase?
centrioles replicate in animal cells; structure of cytokinesis is put into place
What occurs in G2 phase of interphase?
non-dividing phase; most cells in human body are non dividing
What is G0 phase?
Produce daughter cells that have identical genetic components; occurs in
somatic cells
, What is Mitosis?
somatic cells
Where does Mitosis take place? (What cells)
Cell division for gamete (sex cell) production; in specialized tissues; produces
cells with the haploid chromosome number
What is Meiosis?
Haploid
One set of chromosomes (1n)
Diploid
Two sets of chromosomes (2n) one from each parent with the 1n chromosome
G1, S, G2
Three phases of interphase?
Division of cytoplasm
What is cytokinesis?
cells with more than one nucleus
In the cells of some organisms, mitosis occurs without cytokinesis, this will result in ...
Prophase I (Meiosis)
Spindle formation; breakdown of nuclear envelope; nucleoli disappear; chromosomes
condense. Each chromosome consists of two chromatids from S phase of interphase.
Homologous chromosome pairs lie next to one another. Crossing over of chromatids
between pairs (chiasma formation) occurs.
Metaphase I (Meiosis)
Homologous chromosome pairs align on equator of spindle. Kinetochores of sister
chromatids are attached to fibers going to the opposite pole.
Anaphase I (Meiosis)
Homologous pairs of chromosomes separate
Telophase I (Meiosis)
Nuclear membrane may or may not reform.
Cytokinesis may or may not occur.
Prophase II (Meiosis)