Genetic Technology

Question 1

Genetic engineering:

Answer 1

any procedure in which the genetic information in an organism is changed by altering the base sequence of a gene or by introducing a gene from another organism; the organism is then said to be a genetically modified organism (GMO)

Question 2

Recombinant DND(rDNA):

Answer 2

DNA made by artificially joining together pieces of DNA from two or more different species

Question 3

Transgenic organism:

Answer 3

any organism that contains
DNA from another source, such as from another individual of the same species or from a different species

Question 4

genetically modified organism (GMO):

Answer 4

any organism that has had its DNA changed in a way that does not occur naturally or by selective breeding

Question 5

Vector and examples:

Answer 5

a means of delivering genes into a cell used in gene technology;
plasmids and viruses and liposomes

Question 6

💤

Answer 6

Unlike selective breeding, where whole sets of genes are involved, genetic engineering often results in the transfer of a single gene

Question 7

restriction endonuclease (restriction enzyme):

Answer 7

an enzyme, originally derived from bacteria, that cuts DNA molecules; each type of restriction enzyme cuts only at a particular sequence of bases

Question 8

Bacteriophage (phage):

Answer 8

a type of virus that infects bacteria; phages have double-stranded
DNA as their genetic material

Question 9

Gene prob:

Answer 9

a length of single stranded DNA that has a complementary base sequence to another piece of DNA that you are trying to detect

Question 10

Restriction enzymes either cut straight across the sugar-phosphate backbone to give………………. Or they cut in staggered fashion to give ……………..

Answer 10

Blunt ends
Sticky ends

Question 11

💤

Answer 11

Bacterial DNA is protected from such an attack either by chemical alteration to the bases in DNA or by not having the target sites

Question 12

These target sites or restriction sites are specific sequences of ……to…… bases.

Answer 12

4to6

Question 13

💤

Answer 13

Many but not all restriction sites are palindromic(the sequence reads from both directions)

Question 14

Finding the specific piece of DNA required involves separating the lengths of DNA using ……….and………

Answer 14

Gel electrophoresis and gene probes

Question 15

💤

Answer 15

Multiple copies of the required piece of DNA can be made using the PCR(polymerase chain reaction)

Question 16

Genome:

Answer 16

the complete set of genes or genetic material present in a cell or an organism; the genome of a eukaryote includes the DNA in the nucleus and in the mitochondria; the genomes of plants include chloroplast DNA

Question 17

Polylinker:

Answer 17

Several single target sites for different restriction enzymes in a short length of DNA

Question 18

Features of pUC group of plasmids:

Answer 18

1)low molecular mass so they are readily taken up by bacteria
2)an origin of replication so they can be copied
3)polylinker
4)one or more marker genes allowing identification of cells that have taken up the plasmid

Question 19

💤

Answer 19

A small proportion of bacteria perhaps 1% take up plasmids with the gene and are said to be transformed

Question 20

Liposomes:

Answer 20

Tiny spheres of lipid containing DNA

Question 21

For The next step in the process is to get bacteria to take up the plasmids. First, the bacteria and plasmids are put into a solution with a high concentration of

Answer 21

Calcium ions

Question 22

Promoter:

Answer 22

A length of DNA that includes the binding site for RNA polymerase where transcription of a gene or genes begins; in eukaryotes promoters also have sites for binding of transcription factors

Question 23

Polymerase chain reaction (PCR):

Answer 23

an automated process that amplifies selected regions of
DNA using alternate stages of polynucleotide separation (denaturation of DNA) and DNA synthesis catalysed by DNA polymerase

Question 24

Summary of PCR process:

Answer 24

1. DNA is heated briefly to denature the DNA, which separates the double helix.
2. Primer DNA added after cooling.
   Complementary base pairing occurs.
3. DNA polymerase uses free dNTPs to synthesise complementary strands of DNA.
4. The length of DNA has been copied and forms part of two
   DNA molecules.

Question 25

DNA hybridization:

Answer 25

binding together of two molecules of single-stranded DNA by complementary base pairing

Question 26

DNA is negatively charged because of….

Answer 26

Phosphate groups in the phosphate-sugar backbone

Question 27

Types of gels in gel electrophoresis:

Answer 27

1.polyacrylamide:used for separating small fragments of DNA
2.agarose(a kind of polysaccharide produced from seaweed): used for separation of fragments that are between 100 base pairs and 50000 base pairs in length.

Question 28

VNTRs(mini satellites):

Answer 28

have base sequences of between 10 to 100 base pairs in length that are repeated between 5 and 50 times.
They were used in the first form of genetic fingerprinting to give the ladder-like bands on gel

Question 29

STR(micro satellites):

Answer 29

Short tandem repeats. STRs are repeated sequences of nucleotides which are much shorter than minisatellites. STRs are composed of 2 to 5 nucleotides which are repeated 10 to 30 times. One STR has the base sequence CACACA repeated between 5 and 20 times. As with minisatellites, the number of repeats in any one STR is variable.