Unit 6 - topic 6

Question 1

eukaryotic gene expression

Answer 1

the phenotype of a cell or organism is determined by a combination of genes that are expressed and the levels that they are expressed

Question 2

differential gene expression

Answer 2

differences between cell types

Question 3

eukaryotic gene expression is regulated at

Answer 3

different stages

Question 4

if DNA is tightly wound it is

Answer 4

less accessible for transcription

Question 5

DNA can be modified by

Answer 5

histone acetylation and DNA methylation

Question 6

histone acetylation

Answer 6

adds acetyl groups to histones which loosens DNA

Question 7

DNA methylation

Answer 7

adds methyl groups to DNA, which causes chromatin to condense

Question 8

epigenetic inheritance

Answer 8

• chromatin modifications do not alter nucleotide sequence of the DNA, but they can be heritable to future generations
• modifications can be reversed, unlike mutations
• explains why one identical twin may inherit a disease while the other does not

Question 9

transcription initiation

Answer 9

• once chromatin modifications allow the DNA to be more accessible, specific transcription factors bind to control elements
• sections of non coding DNA that serve as binding sites
• gene expression can be increased or decreased by binding of activators or repressors to control elements

Question 10

RNA processing

Answer 10

alternative splicing of pre-mRNA

Question 11

translation initiation

Answer 11

• translation can be activated or repressed by initiation factors
• microRNAs and small interfering RNAs can bind to mRNA and degrade it or block translation

Question 12

eukaryotic development

Answer 12

• during embryonic development, cell division and cell differentiation occurs
• cells become specialized in their structure and function

Question 13

morphogenesis

Answer 13

physical process that gives an organism its shape

Question 14

cells differentiate during early development by

Answer 14

cytoplasmic determinants and induction

Question 15

cytoplasmic determinants

Answer 15

substances in the maternal egg that influence cells

Question 16

induction

Answer 16

cell to cell signals that can cause a change in gene expression

Question 17

both cytoplasmic determinants and induction influence

Answer 17

pattern formation- a “body plan” for the organism

Question 18

homeotic genes

Answer 18

map out the body structures

Question 19

as cells differentiate

Answer 19

apoptosis plays a critical role

Question 20

apoptosis

Answer 20

programmed cell death
allows structures to take their form