Lecture 11

Question 1

either convert open euchromatin into closed heterochromatin or convert closed heterochromatin into open euchromatin

Answer 1

Chromatin remodeling complexes

Question 2

1st chromatin remodeling complex to be isolated

Answer 2

SWI/SNF

Question 3

Example of SWI/SNF complex in euchromatin

Answer 3

HO in yeast

Question 4

SAGA and SWI/SNF recruitment from SWI5P leads to the…

Answer 4

conversion to euchromatin in the promotor region

Question 5

Function of SAGA

Answer 5

Adds acetylcholine groups to nucleosomes

Question 6

Al l repressive chromatin types in mammals are associated with

Answer 6

DNA methylation

Question 7

When euchormatin converts to Heterochromatin, what is added?

Answer 7

DNA methylation

Question 8

The slower the dividing organism, the more…

Answer 8

DNA methylation

Question 9

Once DNA methylation
is established, it can be Maintained by…

Answer 9

Maintenance methylate

Question 10

Chases DNA polymerase and methylates dna behind it

Answer 10

Methylate

Question 11

term for a precursor to living cells

Answer 11

Protobiont

Question 12

consisted of an aggregate of molecules and macromolecules that acquired a
boundary, such as a lipid bilayer

Answer 12

Protobiont

Question 13

maintained an internal chemical environment distinct from that of its
surroundings

Answer 13

Protobiont

Question 14

RNA proto-viruses may have used ___ to multiply

Answer 14

lipid bilayer spheres

Question 15

may have provided an enclosed arena for RNA replication from an RNA template and for protein synthesis

Answer 15

lipid bilayer spheres

Question 16

Some genes do not encode polypeptides, but are transcribed into

Answer 16

Non coding RNAs (ncRnas)

Question 17

perform a spectacular array of cellular functions in bacteria, archaea, and eukaryotes

Answer 17

NcRnas

Question 18

In most cell types, ncRNAs are more abundant than ___

Answer 18

mRNAs

Question 19

In a typical human cell, only about ___ of transcription involves the
production of mRNAs, whereas ___ of it is associated with making ncRNAs.

Answer 19

20%, 80%

Question 20

a recently discovered ncRNA that alters chromatin structure

Answer 20

HOTAIR

Question 21

The HOTAIR gene is located on human chromosome __ within a cluster of genes called the HoxC genes

Answer 21

12

Question 22

Acts as a scaffold that guides two histone-modifying
complexes to their target genes

Answer 22

HOTAIR

Question 23

HoxC is controlled by what kind of genes?

Answer 23

Polycomb

Question 24

transcribed from the opposite (antisense) strand with respect to the HoxC genes

Answer 24

HOTAIR

Question 25

Conversion of euchromatin to H3K27me3 heterochromatin (a.k.a. Polycomb heterochromatin) requires…

Answer 25

(1) deacetylation (2) demethylation of H3K4me3 (if present) (3) methylation at H3K27 to produce H3K27me3

Question 26

HOTAIR Binds two Protein complexes leading to Transcriptional Repression

Answer 26

Lysine specific demethylase 1 (LSD1) and Polycomb repressive complex 2 (PRC2)

Question 27

Removes H3K4me3 Which is a euchromatic histone modification

Answer 27

LSD1

Question 28

methylates H3K27 three times to form H3K27me3

Answer 28

PRC2

Question 29

Eliminates gene expression

Answer 29

siRNA

Question 30

RNA Interference, mediated by ____ was found to be a form of gene regulation

Answer 30

microRNAs

Question 31

are encoded by genes in eukaryotic organisms

Answer 31

MicroRNAs

Question 32

Give rise to small RNA molecules, typically 21 to 23 nucleotides

Answer 32

microRNAs

Question 33

are small non-coding RNA molecules (containing about 22 nucleotides) found in plants, animals and some viruses, that functions in RNA silencing and post-transcriptional regulation of gene expression

Answer 33

microRNA