MODULE 6 IQ3: Genetic Technologies

Question 1

artificial insemination definition

Answer 1

reproductive technology that involves the deliberate introduction of male sperm into female reproductive tract by a method other than sexual intercourse

Question 2

artificial insemination advantages

Answer 2

• enables superior males to inseminate many more females
• semen can be frozen and transported cheaply over great distances
• generally very expensive

Question 3

animal husbandry definition

Answer 3

collection of semen from the male and the insertion of fresh/stored sperm into the female reproductive tract. semen can be frozen using a technique known as cryopreservation

Question 4

animal husbandry advantages

Answer 4

• long-term storage and transportation of semen without losing viability
• impregnation of multiple female animals in different geographic locations
• viable breeding option for farmers who cannot afford or do not want to maintain a large male animal

Question 5

human reproductive technologies

Answer 5

Intrauterine insemination (IUI), In Vitro fertilisation (IVF)

Question 6

intrauterine insemination (IUI) defiintion

Answer 6

used when male is unable to engage in sexual intercourse, has low sperm count or when donor sperm is used.
- female fertility issues such as endometriosis can also require IUIs

Question 7

IUI process

Answer 7

• semen is directly inserted into women’s vagina, cervix or uterus close to ovulation phase of menstrual cycle
• may require medication to stimulate ovulation
• less invasive form of fertility treatment and requires little to no recovery time

Question 8

in vitro fertilisation (IVF) definition

Answer 8

mixing of sperm and ovum in a nutrient medium outside the woman’s body
- use when woman’s fallopian tubes are blocked

Question 9

IVF process

Answer 9

• women are stimulated with injected medications to produce multiple egg development
• minimum number of 4-5 follicles needed
• when follicles mature, a procedure is performed to remove the eggs from the follicles
• eggs are fertilised with partner’s sperm outside body
• 1 of 2 embryos are transferred to woman’s uterus where they hopefully implant and develop into a baby

Question 10

artificial pollination definition

Answer 10

deliberate selection of useful plant varieties by breeders –> deliberate interbreeding of plants carrying desirable characteristics

Question 11

types of artificial pollination

Answer 11

mechanical pollination, hand pollination

Question 12

mechanical pollination

Answer 12

• mass dusting of pollen onto plants from small aircrafts or large blowers
• accuracy of pollen reaching plant is limited

Question 13

hand pollination

Answer 13

• small brush to transfer the pollen from one plant to the stigma of another plant
• more accurate than mechanical pollination
• takes more time and labour

Question 14

whole organism cloning definition

Answer 14

a clone that is a genetically identical copy of a gene, cell or organism

Question 15

applications of whole organism cloning

Answer 15

animal husbandry, agriculture
- limited to mammals such as cattle, chickens, sheep and dogs

Question 16

disadvantages of whole organism cloning

Answer 16

• higher rate of mortality
• health problems

Question 17

artificial embryo twinning

Answer 17

mimics the natural process which leads to identical twins where the embryo splits in 2 very early in the process leading to 2 separate individuals
- genetically identical
- carried out in laboratory petri dish
- early embryo is separated into individual cells and allowed to continue dividing
- transferred into a surrogate mother

Question 18

somatic cell nuclear transfer (SCNT) definition

Answer 18

removes single set of chromosomes from an egg cell and replaces them with the nucleus of a somatic cell taken from the organism being cloned. once embryo is developed, it is transferred to uterus of a surrogate female organism

Question 19

example of SCNT

Answer 19

dolly the sheep
- cells from udder of an adult sheep was collected and transferred to egg cell whose DNA is removed
- egg is implanted into female sheep surrogate and following gestation, live sheep is born
- lamb is genetically identical to sheep whose tissues were sampled

Question 20

gene cloning definition

Answer 20

produces exact copies of a gene of interest. the end product is many copies of a specific gene

Question 21

in vivo gene cloning

Answer 21

• uses restriction enzymes, ligases and vectors to incorporate the desired gene into the DNA of a living organism where this gene will replicate
• since genetic code is universal (nucleotides), the original gene taken from one organism will express the same protein in the host organism

Question 22

in vitro gene cloning

Answer 22

polymerase chain reaction (PCR) is used to produce multiple copies of the specific gene

Question 23

applications of in vitro gene cloning

Answer 23

DNA and genome sequencing, characterising genes, gene therapy

Question 24

DNA and genome sequencing in in vitro gene cloning

Answer 24

obtains DNA sequence of different species –> compared to understand evolutionary relationships and the changes in DNA sequences –> sequences pierced together and genes mapped to their location within the genome sequencing

Question 25

characterising gene in in vitro gene cloning

Answer 25

• scientists examine how gene expression may be regulated by other nearby genes or the environment and how mutations can disrupt gene expression and lead to disease
• manipulate the expression of cloned genes to understand their functional roles

Question 26

gene therapy in in vitro gene cloning

Answer 26

insertion of genes into an individual’s cell to correct or replace defective gene function that leads to disease

Question 27

recombinant DNA (rDNA) definition

Answer 27

DNA that results from moving a section of DNA from its normal location and inserting it into DNA at another site
- can occur naturally or it can occur by using biotechnology

Question 28

example of recombinant DNA

Answer 28

BT cotton
- attracts many insect pests
- they are sprayed with insecticides before crop is harvested
- insecticides are expensive
- transgenic crop that contains two genes from the soil bacterium, Bacillus thuringiensis
- decreases environmental impacts of pesticides and saves farmers money

Question 29

plasmids definition

Answer 29

small circular DNA molecules found in bacteria

Question 30

recombinant DNA process: step 1 isolation of genetic material

Answer 30

isolate desired DNA from other molecules in cell. addition of ethanol caused DNA to precipitate out as fine threads. spooled out to give purified DNA

Question 31

recombinant DNA process: step 2 selection of vector

Answer 31

vector is any DNA molecule which is capable of multiplying inside host to which gene of interest is integrated for cloning
- common vectors include plasmids & phage vectors

Question 32

recombinant DNA process: step 3 restriction enzyme digestion

Answer 32

restriction enzyme cuts DNA at specific locations. involves incubation of purified DNA with selected restriction enzyme, at conditions optimal for that specific enzyme. restriction enzyme cuts a particular DNA sequence. cut ends have many free sites for hydrogen bonding with other complementary DNA

Question 33

recombinant DNA process: step 4 ligation of DNA molecules

Answer 33

purified DNA and vectors of interest are cut with the same restriction enzyme. joins DNA and cut vector with DNA ligase –> called ‘ligation’. resulting DNA molecule is a hybrid of 2 DNA molecules: the interest molecule and the vector

Question 34

recombinant DNA process: step 5 insertion of recombinant DNA into host

Answer 34

recombinant DNA is introduced to recipient host as a bacterial cell –> called ‘transformation’. since bacterial cells do not accept foreign DNA easily, they are treated to make them ‘competent’ to accept new DNA

Question 35

recombinant DNA process: step 6 isolation of recombinant cells

Answer 35

filtering transformed host cells. for isolation of recombinant cells from non-recombinant cells, the marker gene of plasmid vector is employed

Question 36

transgenic animals

Answer 36

animals used to study disease progression and potential treatments
- phenotype of an animal gives the first indications of the function of the protein encoded by the gene

Question 37

genetically modified organisms (GMOs) definition

Answer 37

alteration of organism’s genome for the transfer of genes from one organism to another
- an organism that has had genes from another species inserted is a transgenic organism

Question 38

GMOs process

Answer 38

because DNA code is universal, almost any gene transferred will express protein that is expressed in original organism