Gene Expression

Question 1

What are epigenetics (explain how it works)

Answer 1

inherited factors which make genes more/less likely to be expressed.

1. info is copied from DNA onto mRNA, then translated into a number of amino acids which form a protein
2. Genes used to make mRNA are said to be ‘switched on’, genes not used to make mRNA are ‘switched off’

Question 2

What are some factors determining gene expression

Answer 2

age of cell, time of day, signals from other cells, environment, if the cell is dividing

Question 3

what is a genome

Answer 3

heridatry information encoded in a persons DNA

Question 4

what is a epigenome and what happens if a genome is abnormal

Answer 4

all factors which determine which genes are switched on. this controls which genes are active in a particular cell and so what proteins are produced
if a genome is abnormal,cells maybe weird and have disease

Question 5

Explain chromatins and histones

Answer 5

when the cell is not dividing, DNA forms a tangled network called chromatin. During cell division DNA molecules are coiled around proteins called histones

Question 6

explain histone modification

Answer 6

1. an acetyl group (CH3COO) may be added to a histone protein by acetylations, which enhances gene expressions

Question 7

do stress, poor nutrition, toxins and drugs change DNA

Answer 7

no they just affect the transcription and translation process