Ch 6

Question 1

how do we map species genomes?

Answer 1

DNA sequencing

Question 2

how can you identify the unique genetic makeup of individuals?

Answer 2

DNA profiling

Question 3

what are the applications of recombinant DNA technology?

Answer 3

agriculture and environmental conservation

Question 4

biotechnology

Answer 4

the use of living things to make new products or systems e.g. using yeast to ferment wine

Question 5

Genetic engineering is…

Answer 5

change the genetic sequence of an organism using biotechnology techniques

Question 6

what are organisms created to benefit human use called

Answer 6

Genetically Engineered Organisms (GMOs) or transgenic organisms

Question 7

what do restriction enzymes do

Answer 7

cut DNA at specific restriction sites into smaller pieces called restriction fragments
different restriction enzymes have different restriction sites & most recognition sequences are complementary segments of DNA

Question 8

what are sticky ends and blunt ends?

Answer 8

types of cuts formed from restriction enzymes, sticky ends have overhanging steps while blunt ends do not (clean cut)

Question 9

what’s DNA ligase

Answer 9

an enzyme used to join different pieces of DNA together

Question 10

What does PCR stand for and what are the steps?

Answer 10

Polymerase chain reaction
1 - denaturation
2 - annealing
3 - extension

Question 11

why would you need PCR

Answer 11

Eukarotic somatic cells have only 2 copies of a gene of interest and prokaryotic cells only have one copy therefore only a small sample is available for analysis
PCR will increase the amount of DNA available for analysis

Question 12

what components are required for PCR

Answer 12

DNA template to be copied
DNA polymerase
Buffer solution containing salts
A supply of nucleotides (A, G, C, T)
2 primers (these are the starting point where DNA polymerase can add new DNA nucleotides)

Question 13

Denaturation

Answer 13

DNA is heated to 95oC, breaking H-bonds between the bases, causing denaturation (aka melting stage)

Question 14

Annealing

Answer 14

temp is reduced to 50-60oC, allowing primers to anneal (join) to complementary sequences. Base pairing occurs and the formation of new H-bonds

Question 15

Extension

Answer 15

temp is raised to 72oC, optimum temp for DNA polymerase used in PCR. Starting at primers, new DNA strands are synthesised…results in 2 copies of DNA.

Question 16

what are the 3 ways we can visualise DNA

Answer 16

separate the fragments according to size (gel electrophoresis)
DNA fragments can be identified using a DNA probe
nucleotide sequence can be analysed using DNA sequencing

Question 17

gene probe

Answer 17

a molecular tool that is used to search for a specific gene sequence within the genome

Question 18

how does gel electrophoresis seperate DNA?

Answer 18

because the phosphate group of DNA is negatively charged, the molecule will migrate towards the positive electrode.
the SMALLER the fragment the further it migrates
DNA can be identified by comparing to known samples

Question 19

how does DNA sequencing assist scientists

Answer 19

DNA sequencing determines the exact nucleotide sequence of a gene therefore helps scientists identify mutations (deletions/substitutions) in an individuals genome (eg. cystic fibrosis/sickle cell anemia)

Question 20

what can transferring genes be used for

Answer 20

for gene therapy, useful genes resistant to disease etc…
a gene of interest can be inserted into a vector that will carry the gene/DNA to the desired organism

Question 21

what vectors can be used for gene therapy

Answer 21

plasmids
viruses
liposomes

Question 22

what process involves DNA being incorporated into the DNA of another organism

Answer 22

ligation

Question 23

how can scientists isolate specific genes

Answer 23

using restriction enzymes

Question 24

what are Short Tandem Repeats (STRs)

Answer 24

sections of non-coding DNA that are repeated many times

Question 25

what’s DNA profiling used for

Answer 25

determining how similar or different individuals are based on how often their DNA repeats STRs

Question 26

what’s the process at which the bacteria take up the plasmid called

Answer 26

transformation

Question 27

what’s one advantage of genetic cloning using bacteria compared to PCR

Answer 27

genetic cloning can replicate larger DNA sequences than PCR

Question 28

what are the uses of microarrays

Answer 28

determines the presence of genes & genetic diseases
detects change in the expression (activity) of genes

Question 29

what are microarrays

Answer 29

A microarray is a laboratory tool used to detect the expression of thousands of genes at the same time. DNA microarrays are microscope slides that are printed with thousands of tiny spots in defined positions, with each spot containing a known DNA sequence or gene. these slides are referred to as gene chips or DNA chips. The DNA molecules attached to each slide act as probes to detect gene expression