mitosis and meiosis Flashcards
What is the cell cycle?
The process of growth and divsion for cells
What are the stages of the cell cycle
G0, G1, S, G2, mitosis
What happens during G0?
Cell is performing its normal function and is not preparing for division
What happens during G1?
Growing and preparing for division
What happens during S?
DNA is duplicated
What happens during G2?
Genetic material is condensed to prepare for division
What happens during mitosis?
Creates two daughter cells from a single parent cell.
What happens during interphase(G0,G1,S)?
the cell is visibly larger and has twice the amount of DNA than a normal cell
What happens during prophase?
Chromosomes are further condensed and are now two sister chromatids attached by a centrosome. The nuclear member disappears and centrioles move towards opposite poles. The miotic spindle starts to form.
What happens during prometaphase?
The nucleus has almost disappeared and the chromatids start moving towards the middle of the cell. The kinetochores begin to form, and the spindle fibers elongate the cell.
What happens during metaphase?
Chromosomes are connected to spindle fibers by kinetochores, Chromosomes line up at the metaphase plate.
What happens during anaphase?
Sister chromatids are pulled apart, and the spindle fibers start to shrink, allowing the single chromatids move towards opposite sides of the cell.
What happens during telophase?
Chromosomes are at the opposite sides of the cells and are unwound. Spindle fibers/kinetochores are broken down and the cell starts cleaving.
What happens during cytokinesis?
The cell is completely cleaved and 2 new daughter cells are produced with x2 the DNA
What happens during meiosis?
Creates reproductive cells(gametes). four daughter cells with a
variety of chromosomes to allow for genetic diversity in offspring are the outcome. goes from diploid to halpoid
What are the stages of meiosis I?
Prophase I, Metaphase I, Anaphase I, and Telophase I
What happens during meiosis I
2 daughter cells with x2 the DNA is formed
-Prophase I homologous chromosomes undergo crossing over -Metaphase I homologous chromosomes align at the metaphase plate side by side
-Anaphase I sister chromatids stay together while homologous chromosomes are separated
What the the stages of meiosis II?
prophase II, metaphase II, anaphase II, telophase II
What happens during meiosis II?
The cells will split and create two more unique daughter cells with n amount of DNA. (it is like mitosis)
- Prophase II has no crossing over
-Anaphase II sister chromatids are split
When does crossing over occur?
During prophase I
True or false. We are 100% like our parents and siblings
false
What are the 4 stages of crossing over?
- Chromosomes pair up (homologs create a tetrad and a centromere attaches them)
- Crossing over (genetic material is exchanged at the chiasmata)
- Recombination(creates new combinations of genes that are different than the parent.)
- Separation(chromosomes are pulled apart in anaphase I)
True or false. there are many enzymes involved in crossing over.
true
What is topoisomerase?
It alleviates any tension that is created by the unwinding of the double helix of DNA
