Epigenetics Flashcards
1
Q
what are Epigenetics?
A
- the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself.
- epigenetic is the study of the epigenome ( a system of gene that exists outside the DNA)
- The epigenome are factors that control what controls what parts of the DNA are activated. These factors can either be intra cellular.
2
Q
Each DNA strand is non dividing cell clues is found as fine strands of chromatin that wrap around the four Pairs histone protein molecules to form nucleosome. there are 2 types of these chromatids? What are they?
A
heterochromatids: tightly wrapped around the histone proteins
eucromatids: loosely wrapped around the histone proteins contains genes that can be transcribed
3
Q
What is Histone modification?
A
- histone modifications are not permanent chemical tabs that are added to histones/ DNA to determine if a certain gene can be coded or note. Histone modifications can be reversed according to the chemical environment of the cell.
- DNA ethylene is a further step of this process when a chemical tag is added to a gene to stop it from being transcribed
4
Q
What are the two types of types of identical twins
A
- dizygotic twins or fraternal twins are twins are twins that are developed from a different egg and fertilised by a different spree cell.
- Monozygotic twins are twin that are developed from 1 zygote that splits into two embryos which because they have the same genotype they are identical.