Unit 3 Final Sprint

Question 1

In situ hybridization (when to use, what it is)

Answer 1

Used when you want to see where in an organism a gene is being expressed (create a probe complementary to mRNA you want to study, introduce organism to it, then look at it under a microscope)

Question 2

Reporter Assay

Answer 2

study signaling pathways in gene regulation (reporter gene, think of it like gfp)

Question 3

Enhancer

Answer 3

region of DNA bound by activators that increase the likeliness that transcription will occur

Question 4

operator

Answer 4

What repressive transcription factors bind to (so think of the site lacI binds to)

Question 5

Enhancer, operators, and promoters are

Answer 5

not part of the DNA sequence (they’re upstream)

Question 6

When is RNA sequencing used

Answer 6

When you want to measure gene expression of all genes in each sample to see differences.

Question 7

Necessary Components of a plasmid vector

Answer 7

Origin of replication, terminator, promoter, Amp resistance (selectable marker), gene (cDNA), bacterial promoter

Question 8

How do we go through bacteria transformation

Answer 8

Cold causes pores in the membrane in which we can insert a plasmid

Question 9

Random Insertions vs Homologous Recombination

Answer 9

Random Insertion: DNA injected into egg, the transgene is integrated into chromosomes of random nuclei, some transgenic cells from germ line and are passed on Gene Targeting: Embryotic stem cells contain inactive gene and are transferred to embryos (selected via neomycin and ganciclovir)

Question 10

In a mouse we’re looking for what neo and what ganciclovir

Answer 10

Neo R and Tk - (or no sensitivity to ganciclovir)

Question 11

How do you make a knockout mouse?

Answer 11

Insert target vector containing neoR and tk into ES of black mouse, Cells are selected by neomycin and ganciclover, only Neo R and no TK survive, Inject ES into the embryo of the brown mouse.

Question 12

What do hox genes do

Answer 12

Hox genes regulate the identity of body parts (not its structure!)

Question 13

How do hox proteins work?

Answer 13

Hox proteins are sequence-specific DNA binding proteins and they exert their effects by controlling the expression of genes within developing body parts

Question 14

What are oncogenes

Answer 14

Proto-oncogenes are genes that normally help cells grow. When a proto-oncogene mutates, it is permanently turned on and causes cell proliferation. (Dominant)

Question 15

What are tumor suppressor genes

Answer 15

TS genes are genes that slow down cell division, repair DNA mistakes, and tells some cells to undergo apoptosis. When the genes don’t work, this results in proliferation and cancer (inactivated in cancer, recessive)

Question 16

ras

Answer 16

Ras is an oncogene, a point mutation causes a loss of functionality. It normally cycles between GTP and GDP, but in this case, it can’t cycle from GTP to GDP activating the signal to proliferate.

Question 17

p53

Answer 17

p53 is a transcription regulator that is activated in response to DNA damage -> no p53 means that the cell goes on without p53 stopping the cell cycle or inducing apoptosis

Question 18

E2F

Answer 18

E2F is a DNA binding protein that activates expression of S phase genes, Rb binds to E2f and activates at R checkpoint, but Growth factor signaling prevents Rb from binding to E2F by phosphorylating it as a result of Ras and GTP

Question 19

Familial retinal Blastoma

Answer 19

autosomal dominant

Question 20

Telomerase

Answer 20

Oncogene, telomerase shortens until cell division stops (telomeres shorten)

Question 21

XPC

Answer 21

recessive, increased sensitivity to sunlight

Question 22

Stem Cells Ranked in potency

Answer 22

Totipotency: can produce all cells in an organism: zygote Pluripotency: can produce all body cells in an organism: iPS cells, ES cells Multipotency can produce cells in “organ”: Adult stem cells; Unipotency: Somatic Cells

Question 23

Stem cells begin differentiation by forming

Answer 23

Progenitor Cells

Question 24

Stem cells are regulated by

Answer 24

ligands from niche cells

Question 25

Stem cells

Answer 25

have to touch the niche to be able to renew, otherwise, they go on to differentiate

Question 26

What controls cell differentiation

Answer 26

regulation of gene expression

Question 27

Forward genetics

Answer 27

one starts with a question regarding a gene and then proceeds to use mutagenesis to identify the genes involved in the process
question -> gene

Question 28

Reverse Genetics

Answer 28

one starts with a gene of interest and study its function

gene -> question

Question 29

___ is epistatic of ____

Answer 29

Ras is epistatic of E2F