Cell Division (Mitosis and Meiosis) Flashcards
What is mitosis?
Cell division in somatic cells.
What are the phases of mitosis?
Prophase, metaphase, anaphase and telophase.
What occurs during prophase?
The nuclear membrane disappears. The centrioles go to opposite poles. The chromatin coils into visible chromosomes. Spindle fibers form between the centrioles.
What occurs during metaphase?
The chromosomes align at the middle/equator of the cell and the centromeres attach to the spindle fibers.
What occurs during anaphase?
The centromeres divide. The spindle fibers pull the chromatids apart to the opposite poles.
What happens during telophase?
The chromosomes are at each pole. The cytoplasm divides and a new nuclear membrane forms. The daughter cells enter G1 phase.
What is the difference in plant cell mitosis?
There are no centrioles so the spindle fibers appear out of the cytoplasm. The cytoplasmic division is done by a cell plate.
What is meiosis?
A two stage cell division in germ cells
What are haploid and diploid cells?
Diploid has a full set of chromosomes (2n) and a haploid has a single set (n)
What are the two outcomes of meiosis?
Reduction division (diploid to haploid) and independent assortment
What is a homoloug?
A pair of chromosomes. Determined by size, banding pattern, and centromere location.
What is a karyotype?
The arrangement of homologous pairs by smallest to largest
What is prophase 1?
Similar to prophase. The homologues find each other and twist together to form a tetrad.
What is metaphase 1?
Similar to metaphase. Chromosomes align on the equator.
What is anaphase 1?
The centromeres do not divide on each chromosome. Each pair of sister chromatids goes to the opposite pole. Diploid to haploid
What is telophase 1?
The chromosomes aggregate at each pole. Cytokinesis occurs.
What is interphase 2?
The nuclear membranes, nucleoli and chromatin reform
What is prophase 2?
Chromosome reappear. Spindle fibers form.
What is metaphase 2?
Chromosomes align on equator.
What is anaphase 2?
The centromeres divide like in mitosis. A chromosome goes to either end of the cell.
What is telophase 2?
Cytokinesis occurs. 4 daughter cells are produced
What is non-disjunction?
Too many or too few chromosomes are in each cell at the end of meiosis. Chromosomes do not divide properly. Can happen in anaphase 1 or 2
What is turners syndrome?
Only one X. A sterile female
What is Kleinfelters syndrome?
XXY. A sterile male
