Mitosis & Meiosis Flashcards
What happens in interphase?
Period between cell divisions
Cells undergo regular normal life functions
What is mitosis
Cell division
1) prophase
2) metaphase
3) anaphase
4) telophase
What is cytokinesis
The division of cytoplasm and organelles
Occurs after mitosis
What happens in meiosis 1
Prophase 1: homologous pairs & cross over
Metaphase 1: chromosomes line up in middle
Anaphase 1: whole chromosomes get pulled to either side doesn’t break centromere
Telophase 1: membrane forms back around 2 cells w/ whole chromosomes
What happens in meiosis 2
Prophase 2: membrane dissolves
Metaphase 2: chromosomes line up on middle (single chromatids)
Anaphase 2: individual chromatids pulled apart, breaks centromere
Telophase 2: membrane forms around 4 cells
Errors in meiosis
Non disjunction when chromosomes fail to separate properly
Results in gametes with more or less than haploid # of chromosomes
What is trisomy
Gain of one extra chromosome
What is monosomy
The loss of one chromosome
Chromosomal errors
Deletions : sections DNA missing
Duplications : sections DNA duplicated
Inversions : sections DNA attached in reverse order
Translocations : sections DNA reattached to wrong chromosome
Down syndrome
Trisomy 21
Turner syndrome
One X no Y
Klinefelter syndrome
Two X one Y
Edwards syndrome
Trisomy 18
