biotech

Question 1

isolation of plant cell

Answer 1

cellulase for breaking the cell wall

Question 2

isolation of fungi

Answer 2

chitinase for removing chitin

Question 3

isolation of bacterial cell

Answer 3

lysozyme for breaking peptidoglycan

found in saliva, tears

Question 4

isolation of DNA from protein rna and lipids

Answer 4

protease RNAse lipase

Question 5

isolation of DNA from garbage

Answer 5

put it in chilled ethanol, it will float

Question 6

genetic scissors

Answer 6

restriction endonuclease

Question 7

what gel is used in gel electrophoresis

Answer 7

agarose gel (red algae)

Question 8

charge on DNA

Answer 8

negative

Question 9

which dye is used in gel electrophoresis

Answer 9

ethidium bromide

Question 10

what are the steps for gel electrophoresis

Answer 10

1. put the fragments in a bed containing agarose gel
2. keep a +vely charged electrode, i.e, anode on the opposite end
3. the dna fragments being -vely charged will get attracted to the anode and rush towards it.
4. the smaller fragments will move fast in comparison to the larger ones
5. once these have settled, put ethidium bromide dye on it
6. now place a uv lamp near the bed, the dna will be visible as orange fragments.

Question 11

what is elution

Answer 11

the process of separating the gene of interest from the gel

Question 12

1st restriction enzyme

Answer 12

hind II - haemophilus influenzae

Question 13

what are sticky ends

Answer 13

overhanging stretches of nucleotides
form h2 bonds with their complimentary cut counterparts
stickiness facilitates the action of DNA ligase…..

Question 14

what are recognition sites

Answer 14

special sites where the restriction endonuclease cut the dna

Question 15

what are the features of plasmids

Answer 15

double stranded dna
always circular
extra chromosomal
non essential
self replicating piece of dna

Question 16

2 types of vectors

Answer 16

expression vectors

cloning vectors

Question 17

what are the properties of vector

Answer 17

origin of replication- decides the copy number
selective marker
cloning site

Question 18

how to separate transformant gene from non transformant

Answer 18

selective marker

Question 19

name an artificial plasmid

Answer 19

pbr322

Question 20

what is insertional inactivation

Answer 20

inactivation of gene for synthesis of enzymes

Question 21

bacteria that infects plants with TI gene

Answer 21

agrobacterium tumifaciens

Question 22

disarmed vector

Answer 22

a vector that could earlier harm the host, but cannot do so now. as dangerous gene is destroyed

Question 23

what do retrovirus do

Answer 23

convert rna to dna

Question 24

list the bt crops

Answer 24

tomato
potato
corn 
cotton- bollworm
rice

Question 25

genes in cotton bollworm

Answer 25

cry I AC | cry II AB

Question 26

genes in cornborer

Answer 26

cry I AB

Question 27

methods of molecular diagnosis

Answer 27

pcr | elisa

Question 28

what is genetic engineering

Answer 28

techniques to alter the chemistry of genetic material

Question 29

what is cloning

Answer 29

the ability to multiply copies of antibiotic resistance gene in E.coli

Question 30

EcoRI

Answer 30

Escherichia coli RY 13

Question 31

what are exonucleases and endonucleases

Answer 31

exonucleases remove nucleotides from ends of the DNA whereas endonucleases make cuts at specific positions within the DNA

Question 32

how does a restriction endonuclease function

Answer 32

1. inspects the length of DNA sequence 2. once it finds its specific recognition sequence it will bind to the DNA and cut each of the 2 strands of the double helix at specific points in their sugar phosphate backbones 3. each restriction endonuclease recognises a specific palindromic nucleotide sequence

Question 33

what is ORI

Answer 33

origin of replication sequence from where replication starts any piece of DNA when linked to the sequence can be made to replicate within the host cells

Question 34

what is transformation

Answer 34

procedure through which a piece of DNA is introduced in a host bacterium

Question 35

what is selectable marker

Answer 35

helps in identifying and eliminating non transformants and selectively permitting the growth of transformants

Question 36

how is a bacterial cell made competitive to take up DNA

Answer 36

1. treating it with specific concentration of a divalent cation such as calcium, which increases the efficiency with which DNA enters the bacterium through pores in its cell wall. 2. rDNA can then be forced into such cells by incubating them w rDNA on ice, followed by placing them briefly at 42°C [heat shock] and then putting them back on ice.

Question 37

what is microinjection

Answer 37

rDNA is directly injected into the nucleus of an animal cell

Question 38

what is biolistic/gene gun

Answer 38

cells are bombarded with high velocity particles of gold/tungsten coated with DNA

Question 39

what is reqd in PCR

Answer 39

template strand DNA polymerase (taq) nucleotides primer

Question 40

steps in pcr

Answer 40

denaturation- the 2 template strands separate at 95°C annealing- primers attach on both the strands when the temperature is lowered to 55°-65°C extension- when the temp is raised to 72°C new strands are formed

Question 41

what are generically modified organisms

Answer 41

plants animals bacteria or fungi whose genes have been altered by manipulation are called genetically modified organisms

Question 42

what is gene therapy

Answer 42

collection of methods that allows correction of a gene defect that has been diagnosed in a child

Question 43

what are transgenic animals

Answer 43

animals that have had their DNA manipulated to possess and express an extra gene

Question 44

how do we benefit from transgenic animals

Answer 44

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