Chapter 11.3.1 (Exam 2) Mitosis Flashcards
Eukaryotic Cells Divide by Mitosis
How is chromatin formed?
DNA molecules are bound to proteins
What are cohesins?
Cohesins are the proteins that hold sister chromatids together during G2 phase after replication
What happens to cohesin at mitosis?
At mitosis, cohesin is removed, except at the centromere
What is the function of condensins?
Condensins coat the DNA molecules and make them more compact
How are DNA molecules organized?
Histones
What are histones?
Histones are proteins with positive charges that attract the negative phosphate groups of DNA
What are nucleosomes?
Interactions between positively charged histones and negatively charged phosphate groups of DNA form beadlike units called nucleosomes
What does mitosis lead to?
Mitosis leads to the production of two nuclei that are genetically identical to each other and to the nucleus of the cell that entered the cell cycle in G1
What are the phases of mitosis?
PPMAT
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
What is the role of the spindles in mitosis?
The spindle moves sister chromatids apart
What determines the orientation of the spindles in mitosis?
Orientation is determined by the centrosome (consists of centrioles)
What do the positions of the centrosomes determine?
At which point an animal cell will divide
When do centrosomes replicate?
S phase
What do centrosomes do during prophase?
During prophase, they move to opposite ends of the nuclear envelope and they identify the “poles” toward which the chromosomes move
