Week 4: Cell Division Flashcards
What is the process of mitosis?
Division of somatic cells
What is the process of meiosis?
Division of germ cells to produce gametes (sperm and egg cells)
How many phases can mitosis be divided into?
Six phases
What occurs during prophase of mitosis?
Chromosomes condense, DNA has already replicated, bipolar spindle develops
What happens during prometaphase of mitosis?
Nuclear envelope dissolves, two sister chromatids are seen, chromosomes begin to move
What occurs during metaphase of mitosis?
Chromosomes fully condensed, chromosomes locate at metaphase plate
What happens during anaphase of mitosis?
Centromeres split, two chromatids are pulled to opposite poles
What is the outcome of telophase in mitosis?
Chromosomes reach poles, start to decondense, nuclear membrane reforms, cytoplasm starts to split
What is cytokinesis?
Dividing of the cell to give two daughter cells, starts in anaphase and continues through telophase
What is interphase in the context of mitosis?
Stage of non-dividing cells, nuclear envelope intact, no chromosomes visible
What drives the separation of sister chromatids during mitosis?
The mitotic spindle, which consists of microtubules
What are the two main types of motor proteins involved in mitosis?
- Kinesins
- Dynein
What is the diploid number in somatic cells maintained by mitosis?
Diploid number (2n)
What is the purpose of meiosis?
Mechanism of cell division for making haploid gametes
How many rounds of DNA replication occur in meiosis?
One round of DNA replication
What happens in the first meiotic division (Meiosis I)?
Chromosome pairs separate after DNA replication
What occurs in the second meiotic division (Meiosis II)?
Chromatids segregate, similar to mitosis
What is recombination in Meiosis I?
Homologous chromosomes line up, join, and exchange DNA
What is the result of random assortment during meiosis?
Many combinations of gametes, leading to genetic diversity
What is nondisjunction?
Failure of paired chromosomes to separate in meiosis I or sister chromatids to separate in meiosis II or mitosis
Define euploidy.
Complete set of chromosomes (n, 2n, 3n etc.)
Define aneuploidy.
Extra copy or missing copy of one chromosome
What is an example of aneuploidy?
Trisomy 21 (extra copy of chromosome 21)
How does meiosis differ between males and females?
Males produce 4 spermatids; females produce 1 egg and 3 polar bodies
What is the primary function of mitosis?
Cell division for growth and repair
True or False: The products of mitosis are genetically identical.
True
True or False: The products of meiosis are diploid.
False
