Why is sppontaneous human muations important, what may affect it and how does it affect it
Spontaneous human mutations are essensial for mutation, but is affected by the age of tha father. This is due to male germ cell division bieng continous throuogt life and all these replications get passed on, these are affected by the exposures of the father.
how does de novo muutations changge across age in mother and father
moothers introduce 15 de novo mutation regardless of the age, where as the father gives 2 extra de novo mutations per year. 20 year olds give out 25 de novo where as 40 yearolds give 65. this increases the chance of children having mental illnessses.
How many mitotic divisions and mieotic divisions to go to a zygote from a primordal female germ cell
22 mieotic division to go to a primary oocyte and then 2 mieotic divisions with sperm to become a zygote
How many mitotic duvusions and meiiotic duvusioons in males
30 mitotic divisions to stem cell then 4 mitotic divisions and 2 mietoc divisions to spermatogonia and then spermatids.
What is epigenetics
Epigeneticcs is the chemical reaction involved in changing the physical properties of DNA without altering the sequence. this makes a gene more or less expressive, and can be passed to future generations and these include enviromental influences and diseases.
what is the difference between heterochromatin and euchoramtin
heterochrmatin is densely packed alllowing for no transcriptiom.
euchormatin is more loosely packed and allows for transchription.
whats DNA methylation
when a metthyl group is attached to the cytosines at the CpG islands. these CpG islands tentd to be in prometer/ reglutory regions of genes. but with mythylatioon of cytosines this turns nto hyper methylation causing it to turn off the gene.
what are some epigenetic modifications
heterochromatin
euchromatin
DNA methylation
Histone modification
Noncodin RNAs
whats histone modification
methylation or acytaltion addition to amino acids in histones. methylation could either loosen or tighten association with DNA
acetylation tend to loosen association by nuetralizing charges on lysine
how are mythl grops transfered during replication
during the S phase the epigenitc tags are also replicated to the daughter DNA strand and in this case it would be the methyl group.
how does nutriotion play a role in epigenome
metabolic pathways responsible for making methyl groups. and play a life long role.
what does BPA do
acts as a epigenome decreasing methylation and causing shut down of protective genes.
what are the challenges of proving epigenetic inheritance
- must rule out possibility of genetic changes due to mutations
- must show that the effects of epigenetics is passed through multipal generations to rule out possibility of direct exposure
- epigenetic changes are trainsient by nature.
