Theme 2d Flashcards
What happens in the G1 and G2 phases
Synthesis of proteins, RNA, metabolites and other DNA
Duplication of chromatids and centrioles between phases
What happens in the s phase
DNA replication
What happens in the M phase
Mitosis
What happens in cytokinesis
Cell division
What is the G0 phase
Resting phase, exits cell cycle
What does progression of the cell cycle depend on
Activation of cyclin-dependant kinase
What are the 3 check points of the cell cycle
1) G1/S (DNA damage checkpoint)
2) G2/M (DNA replication checkpoint)
3) M (mitotic spindle checkpoint)
What is an oncogene
Positive regulators of cell cycle (gain of function)
Gene amplification
What is a tumour suppressor gene
Negative regulators of cell cycle (loss of function)
What are homologous chromosomes
Maternal and paternal pair of chromosomes
Have the same number and order of genes but alleles are different
Mitosis look at textbook
What happens in binary fission
-begins at origin
-cell elongated and bacterial chromosome separates
-cell splits in half
-mitosis evolved from this
After meiosis how are the chromosomes attached
By a protein structure called the synaptonemal complex
What happens after meiosis one (reductional division)
Number of homologous pairs of chromosomes is reduced from 2 in the parental cell to 1 in the daughter cell (haploid but 2 chromatids per chromosome)
Sister chromatids are not identical due to crossing over
What happens during mitosis 2
Same as mitosis 1 but centromere and sister chromatids separate during anaphase 2
Result is 4 cells with haploid number of chromosomes (1 chromatid per chromosome that are not identical) due to crossing over and random assortment