Mitosis And Meiosis Flashcards
In what cells does mitosis occur?
Somatic
Which tissues have continued mitosis after development?
Bone marrow
Spermatogonia
Epidermis
Mucosae
What happens in prophase of mitosis?
Nuclear membrane and nucleolus disappears
Spindle fibres appear
Chromosomes condense
What happens in pro-metaphase of mitosis?
Spindle fibres attach to chromosomes
What happens in metaphase of mitosis?
Chromosomes line up (in any order) along the metaphase plate. Attached to spindle fibres by the centromere.
What happens during anaphase of mitosis?
Replicated chromosomes are pulled apart by spindles (centromere divides). Sister chromatids move to opposite poles.
What happens during telophase of mitosis?
Spindle fibres disappear
Nuclear envelope reforms, chromosomes decondense
Cleavage furrow forms
What happens during cytokinesis?
The cytoplasm divides, splitting into two daughter cells with identical genetic information.
What is the product of meiosis?
Four non-identical haploid cells (n)
In what phase(s) of meiosis is genetic diversity introduced?
Prophase 1 - crossing over occurs
Metaphase 1 - random assortment of chromosomes
What is the product of mitosis?
2 identical diploid (2n) daughter cells
What is aneuploidy?
An error in cell division that results in daughter cells with the wrong number of chromosomes.
One missing - monosomy
One extra - trisomy
What is non-disjunction?
An error in anaphase where both copies of s chromosome go to one pole.
What is anaphase lag?
When a chromosome(s) remain on the metaphase plate for too long and is lost - less chromosomes overall.
