Meiosis & Mitosis Flashcards
What somatic cells and germ cells?
Somatic cells are any body cells that don’t produce gametes
Germ cells are diploid reproductive cells that give rise to gametes
Define haploid and diploid
Haploid - cells with one set of chromosomes
Diploid - cells with two sets of chromosomes
Define homologous and non-homologous chromosomes
Explain the structural relationships of chromosomes, chromatids and DNA
What are the two ways cells divide and what are the differences?
Mitosis is for the normal cell life cycle
Meiosis is for reproduction
What are the other 22 pairs of chromosomes that do not determine sex called?
Autosomes
What are the two chromosomes in each pair called?
Homologous chromosomes (homologous)
What is the human karyotype?
An ordered display of the pairs of chromosomes in a cell
When in the cell cycle does mitosis occur?
Before cytokinesis and after G2
What are the four phases/stages of mitosis?
Prophase
Metaphase
Anaphase
Telophase
What are the three events that are unique to meiosis ?
- At the metaphase plate there are paired homologous chromosomes (tetrads) instead of individual replicated chromosomes
- It is homologous chromosomes, instead of sister chromatids, that separate
- Homologous chromosomes physically connect and exchange genetic information
What are some mechanisms that contribute to genetic variation?
Mutations
Independent assortment of chromosomes
Crossing over
Random fertilisation
How do cells do (DNA replication, reproduction etc) without damage?
Histones are proteins that help with folding of DNA
Methylation can affect how tightly coiled DNA is
DNA gets replicated and transcribed at the correct place at the correct time
