gene expression

Question 1

what are the 4 types of stem cell🧪

Answer 1

totipotent, pluripotent, multipotent, unipotent

Question 2

to what extent can these stem cells differentiate?
totipotent, pluripotent, multipotent and unipotent
🦜🛤️🌱🐉🧪🌴💓

Answer 2

totipotent- any cell
pluripotent- most cells
multipotent- some cells
unipotent- one cell

Question 3

Induced Pluripotent Stem Cells are a Future Stem Cell Therapy.
what can iPSCs be used for?💞

Answer 3

they can regrow damaged tissues

Question 4

what is DNA polymerase?🫧💕

Answer 4

an enzyme which manufactures DNA by joining nucleotides (using a complementary strand as a blueprint)

Question 5

what’s a gene machine?🎀

Answer 5

a computer controlled device that can be programmed to produce short sequences of DNA

Question 6

what is DNA ligase? 🧬

Answer 6

an enzyme which can join the phosphate-sugar framework of two sections of DNA eg joining sticky ends

Question 7

what’s a primer?💐

Answer 7

a short sequence of nucleotides with a set of bases complementary to those at one end of each of the two DNA fragments

Question 8

what is restriction endonucleases?🧚🏼

Answer 8

an enzyme that can recognise specific base sequences in DNA and cut the DNA at that site (the restriction site)

Question 9

what are the 3 ways to obtain a copy of a gene sequence?💓

Answer 9

-using reverse transcriptase
-using restriction endonucleases
-using a gene machine

Question 10

what is recombinant DNA?🪷

Answer 10

where DNA from different organisms or sources is combined together

Question 11

how do you make DNA from mRNA?
which 2 enzymes are used?
what has to be made first?
🛤️🛖🌿🦎🌱💓

Answer 11

mRNA ———> cDNA ———> DNA
reverse DNA
transcriptase polymerase

Question 12

what’s a palindrome?☀️

Answer 12

when the sequence reads the same backwards as forwards

Question 13

what are sticky ends?
what can they do?🌊

Answer 13

small tails of unpaired bases
they can hydrogen bond to complementary sequences

Question 14

what do these enzymes catalyse?💞
-restriction endonuclease
-DNA polymerase
-reverse transcriptase
-DNA ligase

Answer 14

-recognition and cutting of DNA at specific base sequences
-formation of a new DNA strand during DNA replication
-production of a cDNA fragment from an mRNA strand
-binding of DNA fragments

Question 15

what is gel electrophoresis?🧪

Answer 15

a process used to seperate the DNA fragments and proteins according to their size using an electric current

Question 16

what is genetic fingerprinting?💞🧬

Answer 16

a technique that can detect differences in people DNA using short repeating bases (VNTRs)

Question 17

what is in-vivo cloning?💞💝💕
example?
how long is the process?

Answer 17

takes place inside a living organism.
eg. DNA fragments can be transferred to a host cells where they’re amplified
long

Question 18

what are proto-oncogenes?
what are oncogenes?
🪼🦎💓

Answer 18

proto-group of genes involved in promoting cell division
oncogene-mutated proto-oncogenes, they’re permanently switched on which overstimulates cell division

Question 19

what’s in-vitro cloning?🐠🐋🐟
example?
how long?

Answer 19

takes place outside of a living organism, in a controlled environment eg test tube
eg DNA is amplified using a PCR in a thermonuclear
makes millions of copies of DNA in hours

Question 20

what does siRNA do?
how does it do this?
🧬🧪💓

Answer 20

it interferes with translation
it binds to mRNA which prevents it from being translated in the cytoplasm
therefore the gene it codes for isn’t expressed

Question 21

what are 4 types of mutation?💓

Answer 21

additional, deletion, substitution, duplication

Question 22

what are dna probes?🏄🏼‍♀️

Answer 22

short single stranded dna labelled fluorescently or radioactively
they’re complementary to the allele being screened for

Question 23

whats hybridisation?😊
what’s detection?😴

Answer 23

when probes bind to the sequence
when probes are tagged so we can detect and count them

Question 24

pros and cons of genetic fingerprinting?🏝️

Answer 24

+ high specificity
- needs prior knowledge of sequence, can get false pos or negs,

Question 25

uses of genetic fingerprinting?🌊

Answer 25

genetic screening, personalised medicine (targets ur genes), genetic counselling (risk of conditions), cancer management

Question 26

what type of bases does gel electrophoresis need in order to work☀️

Answer 26

non-coding bases (VNTRs)

Question 27

describe the process of gel electrophoresis💗

Answer 27

extract DNA
cut fragments with restriction endonucleases
DNA is placed on agar and voltage is applied
small fragments at the top and larger stay at bottom due to gel resistance
DNA samples labelled with probes bind with the comp VNTRs
xray film placed over the membrane shows position of the fragments
shows the bars which is diff for everyone

Question 28

making DNA fragments
how does genetic engineering and restriction enzymes work?🩷

Answer 28

genetic engineering- taking a gene from one species and putting it in another
restriction enzymes- cut double stranded DNA at specific sites-produces sticky ends

Question 29

making DNA fragments
how does reverse transcriptase work?🌆

Answer 29

extract mRNA (not DNA as there’s more copies)
then mix if with free nucleotides and use reverse transcriptase to form cDNA- can then form DNA or something

Question 30

making DNA fragments
how does a gene machine work?🫶

Answer 30

fix nucleotides onto a support
protecting groups prevent branching of the chain
oligonucleotides are synthesised, protecting groups removed and larger fragment is made

Question 31

making DNA fragments
how to make a transgenic organism?☀️☀️

Answer 31

deliver fragment into organism using a vector eg plasmid
plasmid cut using the same restriction enzymes- makes comp sticky ends
fragment inserted to plasmid using DNA ligase
modified plasmid is recombinant DNA

Question 32

what are sticky and blunt ends?🪸

Answer 32

sticky-still had single stranded areas at the end
blunt-straight cut