gene expression (epigenetics

Question 1

phenotypes

Answer 1

observed characteristics expressed by an organism that results from the interaction between genes and the enviroment

Question 2

genotype

Answer 2

observable traits which are determined by the genes carried by individuals (more about the specific genes and DNA)

Question 3

silencing genes

Answer 3

when genes are turned off by adding or removing chemical groups from DNA or the histone proteins in eukaryotes

Question 4

the base where methyl is added

Answer 4

methyl is added to cytosine through DNA methyltransferases

Question 5

DNA methylation

Answer 5

the methyl group to cytosine inhibits RNA polymerase preventing transcription, silencing the gene, the removal of methyl group allows transcription

Question 6

chromatin definition

Answer 6

is a mixture of DNA and histone proteins which make up chromosomes

Question 7

Euchromatin

Answer 7

acetylation of histones neutralises the negative charge of histones weakening the bond between the negatively charged DNA forming loosely packed euchromatin, allows for transcription

Question 8

heterochromatin

Answer 8

DNA is inaccessible and cannot be transcribed, when there is no acetyl groups as the negative DNA is attracted to the positive histones, firmly packing the histones

Question 9

non-coding RNA

Answer 9

are small RNA molecules that is transcribed from DNA but not translated into a protein

Question 10

types of non coding RNA

Answer 10

Micro RNA, Small interfering RNA, Piwi interacting RNA, long non-coding RNA

Question 11

importance of epigenetics

Answer 11

affect the phenotype of the cell without changing he underlying DNA sequence, epigenetic factors can be inherited

Question 12

epigenetics and development

Answer 12

epigenetic factors are passed on to daughter cells during cell division, and are crucial for the development of specialised cells in multicellular organisms

Question 13

proto-oncogene

Answer 13

promotes cell division

Question 14

tumour suppressing gene

Answer 14

inhibits cell division and tumour development

Question 15

amount of DNA methylation (decrease)

Answer 15

can activate proto-oncogenes and trigger unregulated cell division

Question 16

amount of DNA methylation (increase)

Answer 16

can silence tumour supressor genes and trigger unregulated cell division

Question 17

amount of chromatin remodelling (decreased)

Answer 17

decreased histone acetylation creates more heterochromatin which can silence tumour suppressor genes

Question 18

amount of chromatin remodelling (increase)

Answer 18

increased histone acetylation creates more euchromatin which activates proto-oncogenes

Question 19

chromatin remodelling

Answer 19

is also euchromatin and heterochromatin