AI

Question 1

What is epigenetics?

Answer 1

The study of changes in gene function that are mitotically and/or meiotically heritable and that do not entail a change in the sequence of DNA.

Question 2

How is gene control achieved?

Answer 2

By semi-reversible covalent chemical modifications of DNA bases and the proteins with which DNA is associated in the cells nucleus.

Question 3

What is the correlation between epigenetic marks on the IGF2 gene and body mass index?

Answer 3

Hypomethylation of the IGF2 gene is observed in newborns of obese fathers.

Question 4

What is the objective of gene transcription?

Answer 4

To make ribonucleic acid (RNA), which can be messenger RNA (mRNA) or other types of RNA with different functions.

Question 5

What are the three different RNA polymerase enzymes used to make various types of RNA?

Answer 5

• RNA polymerase I * RNA polymerase II * RNA polymerase III

Question 6

What proteins and factors are required for transcription to begin?

Answer 6

A wide range of other proteins and factors at the gene.

Question 7

What is chromatin and its function?

Answer 7

Chromatin is a range of proteins that package DNA and control access of the transcriptional machinery to the information encoded by DNA.

Question 8

What is the nucleosome core particle and its composition?

Answer 8

The nucleosome core particle organizes 147 base pairs of DNA around an octamer of four core histones: H2A, H2B, H3, and H4.

Question 9

What is the histone fold motif?

Answer 9

A common structural motif found in histones that has been conserved throughout evolution.

Question 10

How do chemical modifications of DNA and associated proteins affect gene expression?

Answer 10

Chemical modifications change the expression of nearby genes, leading to changes in cell functions.

Question 11

What is somatic cell nuclear transfer (SCNT)?

Answer 11

A technique that involves taking a nucleus from an adult cell and inserting it into an unfertilized egg with its own nucleus removed.

Question 12

What is therapeutic cloning?

Answer 12

Using stem cells to create cells identical to a specific individual in order to treat a disease.

Question 13

What are embryonic stem (ES) cells?

Answer 13

Cells derived from the inner cell mass of a blastocyst that can divide a limitless number of times and differentiate into any cell type.

Question 14

What are ES cells?

Answer 14

ES cells are inner cell mass cells that can be grown in the lab and have the ability to form every cell of the embryo and ultimately of the mature animal.

Question 15

Why are ES cells called pluripotent?

Answer 15

ES cells are called pluripotent because they can form pretty much any cell of the embryo except placenta.

Question 16

Why are genes and proteins expressed in ES cells important?

Answer 16

Genes and proteins expressed in ES cells are important for keeping the cells in a pluripotent state.

Question 17

What happens if the conditions for ES cells are not maintained properly?

Answer 17

ES cells can differentiate into other cell types if the culture conditions are not kept just right.

Question 18

What did Professor Yamanaka want to find?

Answer 18

Professor Yamanaka wanted to find a way of creating pluripotent cells from differentiated cells in a lab.

Question 19

What happened when Yamanaka tested the 24 pluripotency genes in mouse embryonic fibroblasts?

Answer 19

Yamanaka identified ten critical genes that could turn embryonic fibroblasts into pluripotent cells.

Question 20

What is the smallest number of genes needed to turn fibroblasts into pluripotent cells?

Answer 20

The smallest number of genes needed is four: Oct4, Sox2, Klf4, and c-Myc.

Question 21

What can reprogrammed cells become?

Answer 21

Reprogrammed cells can become the three major tissue types: ectoderm, mesoderm, and endoderm.

Question 22

What is the technique for direct conversion of human fibroblasts into human neuronal cells called?

Answer 22

The technique is called direct conversion or rolling a ball halfway up Waddington’s epigenetic landscape.

Question 23

What happens to the nuclei of sperm and egg when they fuse?

Answer 23

The nuclei are reprogrammed by the cytoplasm of the egg, losing their molecular memory and becoming blank canvases.

Question 24

What is the efficiency of reprogramming adult cells into iPS cells compared to normal fertilization?

Answer 24

The efficiency of reprogramming is much lower and slower compared to normal fertilization.

Question 25

What must be removed for differentiated cells to become pluripotent cells?

Answer 25

The differentiation-specific epigenetic signature must be removed from the nucleus.

Question 26

What carries the codes for all the proteins in the body?

Answer 26

DNA carries the codes for all the proteins in the body.