Session 3 (Errors In DNA Replication and Gamete Genesis) Flashcards
What are the reasons for replication stress? (3)
Defect in response pathway
Replication machinery factor defected
Factors hinder replication for progression
Explain the Mitotic cell cycle
G1 (gap 1)- organelles divide
S1 (synthesis 1)-dna is replicated
G2 (gap 2)- spindles begin to form and mitochondria divide
Mitosis- PMAT+C
What is a cell’s specific no of cell divisions called?
Hayflick limit
What are the arms of DNA called?
P-short arm
Q-long arm
What is an allele?
Different forms of the same gene
What’s the difference between homologous chromosomes and sister chromatids?
Homo. Chromo. = same DNA sequences and same genes but different alleles
Sister chromo. = identical, same DNA sequence, same genes and same alleles
What gives genetic variation in meiosis?
Random assortment and crossing over
When does a cells become haploid during meiosis?
End of meiosis 1
When does crossing over occur? How?
Prophase 1 by the formation of chiasmata
What names are given to the cells involved in spermatogenesis?
Spermatagonium->primary spermacyte->
secondary spermacyte->spermatid->
sperm
What are the names given to the cells involved in oogenesis?
Oogonium->oocytes (primary and secondary) +polar bodies
->ovum
In what stage of meiosis do the primary oocytes remain in until puberty?
Prophase 1
What happens every month for women that is part of oogenesis?
A single primary oocyte is allowed to complete meiosis 1 (can then be ovulated)
When does the ovum finally complete meiosis?
Shortly after fertilisation
