Cell Division Flashcards
What are the 3 parts of Interphase?
G1&2: growth and function
S phase: synthesis of DNA (identical copy)
Explain Mitosis?
- genetically identical
- asexual
- body cells (somatic)
- right after fertilization
- during growth and healing
- IPMATC
Explain steps of cell division?
Interphase: chromatin, 90% of the time, G1, S phase, G2
Prophase: nucleus disappears, duplicated chromosomes
Metaphase: duplicated chromosomes line up in middle
Anaphase: duplicated chromosomes separate
Telophase: 2 nuclei reappear, unduplicated chromosomes uncoil into chromatin
Cytokinesis: creates 2 cells
Explain the process of cancer?
Repeated mitosis with very short G1 and G2 interphase
- small cells that don’t perform their function
Explain meiosis?
- creating sperm and egg
- cells genetically different/diverse
- I (PMATC) x2
Explain steps of IPMATC in meiosis?
Interphase: G1, S phase, G2
X2
Prophase 1: homogolous pairs form a Tetrad (SYNAPSIS),
swap peices of DNA between one another in Crossing over (CHASMATA) - diversity increases
Metaphase 1: Tetrads alums in the middle
Anaphase 1: tetrads separate into duplicated chromosomes
Telophase 1: duplicated chromosomes unravel into chromatin
Cytokinesis 1: 2 cells created
In the end 4 cells created
What is a diploid?
Full set of DNA in somatic cells (2n)
What is a Haploid?
Half set of DNA in gamete (n)
What is the chromosome count in Mitosis?
Diploid
What is the chromosome count in Meiosis?
Diploid in first cell, and haploid with duplicated chromosomes, then haploid with unduplicated chromosomes
Explain meiosis in spermatogenesis?
All 4 cells are equal in size and all become gametes
Explain meiosis in oogenesis?
Uneven cytoplasm division, 3 polar bodies die and 1 large ovum is created
Explain XY Karyotype?
- male
- non homogolous pair
- no crossing over
Explain XX Karyotype?
- female
- homogolous pair
- crossing over occurs
2 types of chromosomes in Karyotype?
Sex chromosomes: genetic sex and many physical characteristics
Autosomes: pairs 1-22 of first 44 chromosomes, Not involved with genetic sex
Explain Nondisjuction?
- Chromosomes fail to separate during Anaphase 1 or 2
- some gametes have an extra chromosome (Trisomy)
- some gamete’s have one less chromosome (Monosomy)
Only matters if gametes are involved in fertilization.
Explain Ploidy rules?
- Ploidy # decreases = meiosis
- Ploidy # increases = fertilization
- Ploidy # constant = mitosis
Sporophytes?
Generation is diploid (2n)
Gametophytes
Generation is haploid (n)
