The Cell Cycle Flashcards
How do prokaryotes divide? (4)
Binary fission.
- circular DNA molecules are replicated
- DNA molecules attach to different PM parts
- cell elongates
- contraction of PM across the middle of cell produces 2 daughter cells with new cell walls
What is the cell cycle?
A series of events that a cell undergoes, which results in 2 genetically identical daughter cells.
What are the three parts of interphase?
G1: cell growth and checkpoint
S phase: DNA and chromosome replication
G2: cell growth and preparation and checkpoint
What occurs during the G1 phase? (4)
- cell cytosol increase
- protein synthesis for DNA replication
- organelles replicate
- cell will go through check point, of there are any errors cell will either correct them or enter non dividing stage (G0)
What occurs during the s phase of interphase?
- Parent cell replicates DNA
- by the end of s-phase cell will contain double the amount of DNA and chromosomes
What occurs during the G2 stage of interphase? (3)
- cell continues to grow in preparation for division
- synthesis of proteins need for microtubles
- cell undergoes another checkpoint to see if DNA has been correctly duplicated
What occurs during prophase? (3)
- chromosomes condense and become visible
- replicated centrioles move apart
- microtubles extend towards towards centrioles
- nuclear membrane has breaks down
What occurs during metaphase? (3)
- microtubles have have fully formed and are in position
- chromosomes align on the equator of the cell
- nuclear membrane has completely broken down
What occurs during anaphase?
- spindles contract pulling centromeres apart leaving single stranded chromosomes at either end of the cell
What occurs during telophase? (3)
- nuclear membrane forms around each set of chromosomes
- chromosomes de-condense
- spindles begin to break down
What occurs during cytokinesis?
- a contractile ring of protein molecules form a cleavage furrow
- cell splits into two daughter cells
How is cytokinesis different in plant and animal cells different?
During cytokinesis in plants, a cell plate forms in the middle of the cell and it grows towards the cell wall, where as in animals, they form cleavage furrow and the cell membrane constricts.
True or false?
Mitosis is a type of cell division in which a complete set of chromosomes is distributed to each daughter cell.
True. Mitosis does provide a complete set of chromosomes to each daughter cell. They are diploid cells.
True or false?
Binary fission does not require DNA replication.
False. Prokaryotes have a circular DNA chromosomes that needs to be replicated in order to compete mitosis.
What must occur in order for a successful division of sister chromosomes during mitosis?
Mitotic spindles must correctly attach to each sister chromosomes by their kinetochore and contract to pull the sister chromatids to opposite poles.