Unit 4 Flashcards
what is cell division for
reproduction of cells, growth of cells, tissue repair
Condensed chromatin
Chromosomes
non condensed chromosomes
Chromatin
Genetic information is only in chromosome form during
Cell division
When does chromatin condense
After dna replication
Centromere definition??
Region on sister chromatids where they are most closely attached
Kinetochore definition??
Part in chromosome where the spindle fibers attach
What’s a genome?
All of a cells genetic information
How do prokaryotes have their dna
Singular circular dna
How do eukaryotes have their dna
One or more chromosomes
Humans have how many chromosomes?
46
Homologous chromosomes are?
Two chromosomes that are the same length, have same centromere position, and have genes controlling same characteristics
Order of cell cycle?
G1 -> S -> G2 -> Mitosis
G1, S, and G2 are all in
Interphase
What happens in G1
Cell grows and does normal things
What happens in S
DNA replicates
What happens in G2
Final growth, preparation for mitosis
Mitosis results in……
2 identical diploid daughter cells
Order of mitosis steps?
Prophase, Metaphase, Anaphase, Telophase & Cytokenesis
What happens in prophase?
Chromatin condenses, centrosomes appear
What happens in metaphase?
Chromosomes go in middle, they’re connected to centrosomes
What happens in anaphase?
Chromosomes are pulled apart by centrosomes, sister chromatids separate and move to opposite ends of cell
What happens in telophase and cytokenesis?
Two nuclei form, chromosomes uncondense
G1 Checkpoint
Most important checkpoint
Checks for cell size, growth factors, and DNA damage
What happens if G1 checkpoint says stop?
Cell enters G0
G2 Checkpoint happenings
Completion of DNA replication checked
DNA damage checked
What happens if G2 checkpoint says stop?
Cell cycle stops and the cell will try to repair damage, if it cant, the cell will undergo apoptosis