Epigenetics
Name a chemical modification that turns a gene "off"
DNA methylation
The DNA is replicated in this stage
S (synthesis); what enzymes are involved again?
True or False: mitosis produces cells that are genetically identical to the parent
True
What type of mRNA is first made during transcription?
pre-mRNA
Term for the protein complex that DNA is wound around
Histones
"Guardian of the genome" (tumor suppressor gene)
p53
What term describes the condensed form of DNA during mitosis?
chromosomes
What are the two additions that occur at each end of the pre-mRNA?
5' cap and poly A tail
Rats raised by low-nurturing mothers contained this
methylation of DNA (GR gene)
Name one environmental factor that can influence epigenetic changes
diet, stress, grooming (rats)
Name a reason that a cell might undergo apoptosis
DNA damage, failure to pass a checkpoint, etc.
An animal (2n) has 14 chromosomes in its somatic cells, how many will it have after mitosis? In how many homologous pairs?
14 chromosomes; 7 homologous pairs
What is removed from pre-mRNA during processing
introns
A repressor protein is taken off of the DNA, what do you expect?
increased transcription
How does histone acetylation generally affect gene expression?
loosens chromatin --> increased transcription
A cell with damaged DNA continues to divide, what risk does this pose
Cancer
Final step of mitosis when the cell starts to divide
Cytokinesis
Name one reason why cells have checkpoints during the cell cycle
Make sure the cell is big enough, no DNA errors, etc.
Role of "chromatin remodeling"
changes how tightly packed the DNA is to histones
What is happening during metaphase?
Chromosomes are lining up in the middle of the cell and preparing for separation
What are sister chromatids?
Two identical copies of a chromosome attached at a centromere
What is the role of the two additions happening during processing?
Protects against degradation; allows mRNA to leave nucleus
Mitosis ends with ___ cells while meiosis ends with ___ cells
2; 4