Ch. 21

Question 1

EPIGENETICS

Answer 1

How the environment impacts gene expression, - - expression of genes in the progeny had different methylation patterns/Epigenetic patterns, genome responded to environment by activating genes that held onto calories
- gene expression changing persists throughout the next generations
- germ line epigenetic effects

Question 2

Base excision repair

Answer 2

• one strand methylated, one not, they need to be able to be reestablished, need to be created first so they can be passed on

Question 3

EPIGENETICS CONT.

Answer 3

How, through the process of development, a genotype produces a phenotype
- how an embryo develops
- GENETICS: the study of genes and heredity
- CHANGES are responsible for differences in phenotypes in bees

Question 4

What molecular processes lead to epigenetic changes?

Answer 4

• changes in chromatin structure —> alters gene expression
• molecular mechanisms that alter the chromatin structure

Question 5

molecule mechanisms that alter the chromatin structure

Answer 5

• changes in patterns of DNA methylation
• chemical modification of histone proteins
• RNA

Question 6

DNA methylation

Answer 6

Addition of methyl groups to nucleotide bases
- stably maintained through DNA replication

Question 7

Semiconservative replication

Answer 7

Semi conservative remains methylated, while the other is not
- no cell development
- hemimethylation

Question 8

What is most likely to be changed in epigenetic modification?

Answer 8

CPG islands, methyl-cytosine

Question 9

Methlytransferase

Answer 9

Binds to DNA, recognizes the methyl group strand, adds methyl group to strand
- solves issue of semiconservative and methylation

Question 10

Hemimethylation

Answer 10

Only part of the strand is methylated

Question 11

Royal jelly

Answer 11

• suppresses Dnmt3, leading to expression of genes that encode characteristics of the queen
• less methylated
• expresses genes encoding queen characteristics

Question 12

Dnmt3

Answer 12

• de Novo Methyl Transferase
• Methylates DNA

Question 13

Bisulfite sequencing

Answer 13

By sequencing genomic DNA with and without bisulfite treatment, researchers are able to determine the locations of all copies of 5-methyl-cytosine in the DNA
- WHERE ARE THE METHYL GROUPS?
- C to T? Unmethylated, cytosine converted to Uracil

Question 14

Histone modifications

Answer 14

More than 100 different posttranslational modifications of histone proteins (DNA is wrapped around)

Question 15

Modifications include addition of what?

Answer 15

Phosphates
methyl groups
Acetyl groups
Ubiquitin

Question 16

Maintenance of histone modifications

Answer 16

Passed to daughter cells during cell division and to future generations

Question 17

Detecting histone modifications

Answer 17

Chromatin immunoprecupitation

Question 18

Epigenetic effects of RNA molecules

Answer 18

• X inactivation
• paramutation in corn
• si RNA molecules that silences genes and transposable elements
• microRNAs control expression of genes that produce epigenetic effects

Question 19

Epigenetic processes that affect development

Answer 19

• cell differentiation in epigenetic changes
• stem cells: undifferentiated cells
• multi potent: can revert it into a stem cell
• pluripotent: ability to differentiate into any types of cell
• induced pluripotent cells (IPCs): differentiate into many different cells (they are stem cells)

Question 20

Barr Bodies