Cell Division Flashcards
A part of ______ states that all cells arise from
pre-existing cells through ______
1) Cell Theory
2) Cell division
Genome
- all the DNA in a cell.
Chromosomes
- separate DNA molecules that make up the entire genome.
Homologous chromosome pairs
- two different versions of the same chromosome number. One is inherited from mother and one from father.
Sister chromatids
- identical, attached copies
of a single chromosome that form dyads.
Dyads
- replicated chromosomes containing
two sister chromatids that look like an “X”.
Centromeres
- regions of DNA that connect
sister chromatids in a dyad.
Kinetochores
- proteins on the sides of
centromeres that help microtubules pull sister
chromatids apart during cell division.
Karyokinesis
- division of the nucleus.
Cytokinesis
- physical division of the
cytoplasm and cell membrane.
Parent cell
- one parent cell produces two daughter cells after division.
Ploidy
- describes the number of chromosome sets found in the body. Humans are diploid
because they contain two sets of chromosomes (46 chromosomes, 23 pairs),
one from each parent. However, they also have haploid cells (gametes) that only contain one chromosome set (23 chromosomes).
Sex chromosomes
- one pair in the human
body; they determine sex.
Autosomes
- 22 pairs in the human body; they are non-sex chromosomes.
Gametes
- haploid cells (sperm and eggs).
Germ cells
- diploid cells that divide by meiosis to produce gametes.
Gametocyte
- eukaryotic germ cells that can either divide to form more gametocytes or
produce gametes.
Somatic cells
- all body cells excluding the
gametes. Diploid in humans.
Stages in Cell Cycle
1) G1
2) G0
3) S
4) G2
5) M phase
1) => 4) = interphase
Go = Gap Phase 1 (G1) of interphase
Sam = Synthesis Phase (S) of interphase
Go = Gap Phase 2 (G2) of interphase
Make = Mitosis of the M phase
Cake = Cytokinesis of the M phase
G1 (gap phase G1)
- cell grows in preparation
for cell division. Also checks for favorable
conditions. If favorable, the cell will enter the S
phase. If unfavorable, the cell will enter G0
phase.
G0 phase
- cells still carry out their
functions but halt in the cell cycle. Cells
that do not divide are stuck here.
Synthesis phase (S)
- cell replicates its genome
here and moves to G2 phase when completed.
Centrosome duplicates.
Gap phase 2 (G2)
- cell continues to grow and
prepare for cell division by checking DNA for any errors after replication. Also checks for mitosis promoting factor (MPF) aka maturation promoting factor, which needs to be present in adequate amounts for cell
cycle continuation. Organelles are replicated
here.
Microtubule Organizing Centers (MTOCs)
- are present in eukaryotic cells; they organize extension
of microtubules, which are made of the protein
tubulin. MTOCs are responsible for forming the
spindle apparatus, which guides chromosomes
during karyokinesis.
Centrosomes
-are organelles found in animal cells
that contain a pair of centrioles. They act as
microtubule organizing centers (MTOCs).
_______ in the spindle apparatus:
1) Microtubules
Kinetochore microtubules
- extend from
centrosomes and attach to kinetochores on
chromosomes.