Mitosis Flashcards
Cell def
Smallest unit of life that satisfies all properties of life
True or false? Some organisms can be composed of just one cell
True
Why do Cells divide?
Growth and development, tissue renewal(repair tissue damage), reproduction
True or False? All cell types are actively going through the cell cycle
False, example is liver which doesn’t divide until needed
Do Neurons divide?
No
What are the main phases of the cell cycle?
Interphase(90-95% time), Mitotic phase
Name the phases of the interphase
G1 S and G2
What is the purpose of the interphase?
Cell is preparing to divide
What happens during G1?
Cells grow(double size) and organelles duplicate
What happens during S phase?
DNA doubles and duplication of chromosomes
What happens during G2?
Second growth phase, with tubulin and actin protein being made
- Checks everything ready
What happens during mitotic phase
duplicated chromosomes distributed among 2 daughter cells
What are the steps of Mitosis?
prophase,metaphase,anaphase,telophase
Cytokinesis def
division of cytoplasm
Chromosome def
Long linear strand of DNA, containing histones
Centromere def
Place where sister chromatics are attached to each other
What are kinetochores?
Proteins that bind to microtubules(mitotic spindle fiber)
What are somatic cells?
any cell except sperm or egg cells
What are gametes?
Sperm and egg cells
What are autosomes?
chromosomes that are not sex chromosomes
How many chromosomes do gametes have in humans?
23 ( 22 autosome, 1 sex)
What happens during prophase
chromosomes condense
mitotic spindle forms
centrosomes move apart
nuclear envelope breaks down
spindle fibers attach to chromosomes at kinetochore
What do centrosomes do?
organelle that Creates mitotic spindle fibers
What happens during metaphase?
Chromosomes line up in center of cell
What happens during anaphase?
Sister chromatids are separated and pulled to opposite sides
What happens during telophase?
Spindle fibers disassemble
nuclear envelope reforms
Chromosomes uncoil
Do plant cells have centrosomes?
No
How is a cleavage furrow created?
ring of actin microfilaments, ring pinches inwards
How does cytokinesis work in animal cells?
Occurs by cleavage
How does cytokinesis work in plant cells?
Vesicles fuse together and form cell plate
At what point of mitosis are there no longer any chromatids?
after anaphase
