inquiry question 3 module 6 Flashcards
Does artificial manipulation of DNA have the potential to change populations forever?
examples of reproductive technologies
- artificial insemination
- artificial pollination
artificial insemination
involves the assisted placement of sperm into the female reproductive tract
eg. cattle for more yield and IVF for assisted human reproduction for single mothers
artificial insemination effect on variation within species
Increase → allows crosses that would not usually occur due to distance or physical differences which increases variability within a population
Decrease → one donation of sperm can be frozen and used multiple times with increases levels of genes within a population
methodology of artificial insemination
- Collection of semen using an artificial vagina
- Transfer of semen to a sterilised artificial insemination gun
- Insertion of the gun into the female organism’s cervix or uterus through the rectum
advantages of artificial insemination
- Humans are able to select desirable traits to produce offspring with desired characteristics
- Can be used in conservation, to increase the numbers of endangered species such as wildlife conservation
disadvantages of artificial insemination
- decreased genetic variation as if certain traits are continuously selected artificially increasing the allele frequency of those traits
- Susceptibility to extinction due to decreased total gene pool and allele frequency in the population as the same males / females with those traits are reproducing
- Inbreeding which leads to diseases
artificial pollination
assisted transfer of pollen from the male part of a flower to the female part
- selectively breed plants with desirable traits eg more fruit and larger seeds
methodology
1. Pollen (sperm) is removed from the stamen of one plant
2. Pollen applied to the stigma of another plant by the means of forceps
3. Pollen fertilises the ovum
4. The anthers of the plant receiving foreign pollen are removed to avoid self-pollination.
5. Results in fertilisation and the developments of seeds. These seeds may develop into fruits or new plants.
mechanical and hand
how does artificial pollination alter the genetic variation
Increase → allowing crosses that would not have occurred naturally due to distance or physical factors or time
Decrease → if one type of pollen is transferred to many plants → occurs as it is more efficient for farmers to harvest a field of uniform crops (can result in monocultures)
advantages of artificial pollination
- Ensures that all plants within a crop are pollinated and can produce fruit → increases crop yields and profitability
- Used to create new species of plants with desirable characteristics → increasing genetic variation → new allele combinations are being created
disadvantages of artificial pollination
If performed large scale → may create monocultures (little genetic variation as it is not random anymore) ‘
- Species will be vulnerable to sudden environmental changes eg. irish potato famine
define cloning and types of cloning
the process of making an exact copy of something
- gene cloning
- therapeutic cloning
- whole organism cloning
gene cloning, definition, process, applications
process by which a single gene or segment of DNA is isolated so that multiple copies can be made
methodology
1. Gene of interest is extracted from a sample using a restriction enzyme
2. A bacterial plasmid is cut using the same restriction enzyme
3. Gene of interest and cut bacterial plasmid are annealed together using DNA ligase → joins the ‘sticky ends’ together
4. Recombinant plasmid is reinserted back into the bacterial cell
5. Bacterial cell replicates by binary fission → produces many copies of the recombinant plasmid → gene of interest
6. bacteria cells will express the genes
applications:
-human genes cloned for replacement insulin and healthy genes for cystic fibrosis through gene therapy
- transgenic organisms
make therapeautic later
yuhh
whole organism cloning, definition, process, applications, will they actually look the same and techniques used
process of creating an organism which is an exact genetic copy of another organism
Clones theoretically look identical to the parent because they contain the same genetic material but due to environment conditions → expression of genes differ resulting in slightly different phenotypes
- somatic cell nuclear transfer
whole organism cloning effect on variation
Decrease → populations that reproduce sexually
No effect → populations that reproduce asexually eg. vegetative propagation as the clones have already been produced
difference between whole organism and gene cloning
whole organism is produced instead do the copy of a singular DNA segment being replicated
ethical issues with whole organism cloning
- using large number of embryos
- genetic damage to the clone
somatic cell transfer uses
- dolly the sheep
Protects endangered species - Artificial embryo twinning allows many more offspring to be be produced from a single egg → helps farmers increase their cattle numbers or milk production
methodology of somatic cell nuclear transfer
- Somatic cell containing a nucleus is obtained from the organism to be cloned
- An unfertilised egg cell is obtained from a female donor of the same species and the nucleus is removed and discarded
- The somatic cell is fused with the donor egg using an electric pulse and then stimulated with chemicals to start cell division
- The early stage embryo is implanted into the uterus of another female animal → surrogate mother
- Surrogate mother gives birth to the animal that is genetically identical to the adult that donated the somatic cell
applications of somatic cell nuclear transfer
- Enhance the availability of the best possible stock by allowing farmers to be certain of the genetic makeup of a particular animals such as cows with more milk
- protects endangered species
- increase diversity in conservative breeding programs
ethical issues with cloning
- animal welfare
- unforeseen health risks
- reduces genetic diversity in a population –> less likely to survive any sudden environmental changes and is vulnerable to foreign pathogens.
how to verify clones
dna fingerprint analysis
cloning plants
- should be identical but due to environmental conditions results in slightly different phenotypes
asexual reproduction - vegetative propagation: Taking a cutting of a plant (eg. twig/stem) and planting it → new plant is a clone as it contains identical DNA to the parent plant
- tissue culture
Take small amounts of parent tissue and transfer to agar culture medium
Plant hormones are added in order to stimulate division of the cells into small masses of tissue
Growth hormones then added to culture medium → stimulates the development of roots and stems
Tiny plantlets with roots and stems are then transferred into potting trays where they can develop into whole plants
- can be carried out throughout the year
advantages:
- Can produce flowering and fruiting plants more rapidly than growing a plant from the seed
ways to observe the effect of a gene
Knock-out the gene (completely silence it)
Gene will not be expressed → impact can be observed
Knock-in a gene (insert a new gene)
Knock-down or knock-up a gene (reduce or increase gene expression)
crispr-Cas9 can be used
- using mice as they have similar physiology to humans helps study effects of pharmaceutical drugs
ethical: unattended suffering of the individual
transgenic species
organisms that contains genes from another species
and created by taking a gene from one species and inserting it into into the genome of another
- through recombinant dna technologies
methodology
1. Make several copies of the target gene which is to inserted using recombinant DNA technology
2. nsert the target in the organism of interest using a range of methods (microinjection, viral vectors, Ti plasmid insertion, gene gun)
recombinant dna technology
cartifical form of DNA combining/joining DNA from two or more different sources in order to clone a particular gene
- transgenic organisms created
transgenic organism effect on biodiversity
Low genetic diversity → species cannot evolve or adapt to change such as new diseases or climate change (long-term survival of the species)
Producing transgenic animals is time consuming and expensive → once the animal is produced it is likely to be cloned which decreases genetic diversity
Transgenic organisms can also outcompete other species due to the genetic advantage
increases as it heps woth ike pest resistant
examples of transgenic organisms in agriculture
made for improved crop and livestock which increased resistance to harsh environmental conditions
bt cotton –> contains genes from bacterium Bacillus thuringiensis
- allows the plant to naturally produce insecticides
- Naturally produces insecticides → reduces the need to treat the crops using industrial insecticides → significant cost saving
aquaculture
- Genes responsible for the production of growth hormones and antifreeze proteins → inserted into atlantic salmon –> increases biodiveristy
disadvantages of transgenic organisms
- When genetically modified crops are produced for agricultural purposes → monocultures often result –> decreased biodiveristy
recreational transgenic organism
GloFish
brand of genetically modified fluorescent modified
Contain the foreign gene that codes for fluorescent proteins extracted from jellyfish
Increases genetic diversity → a gene is added to the gene pool from a different species
medical applications of transgenic organisms
- using mice as they have similar physiology to humans helps study effects of pharmaceutical drugs
ethical: unattended suffering of the individual
-pharming: use of transgenic organisms to produce pharmaceutical proteins and chemicals
insulin can be produced by transgenic bacteria containing human gene for insulin
- When the insulin gene is expressed by the E coli it will be read and the respective polypeptide protein will be produced → insulin will be synthesised
producing recombinant dna
Using E.Coli bacteria relies on plasmids found in the bacteria
methodology
1. Cut out the target gene or DNA sequence of interest using a restriction enzyme
2. Cut out a section of the plasmid vector using the SAME restriction enzyme (opens a site for the target gene to insert)
3. Mix the target gene with the cut plasmid
4. Anneal the sticky ends of the target gene and plasmid using DNA ligase
5. Reintroduce hybrid plasmid into bacterial cell
6. Recombinant DNA will reproduce asexually → making many copies of the hybrid plasmid → the inserted target genes (referred as the amplification of the target gene)
plasmid
consists of double stranded (circular) DNA that can replicate independently of the bacterial chromosomal DNA that Can be isolated and genetically modified before reinserted back into bacterial cells → useful for producing recombinant DNA
- vectors or agents transferring new genes into bacteria
Bacterial cells reproduce by binary fission → creates copies of the recombinant plasmids
restriction enzymes
different restriction enzymes will produce plasmid fragments of different lengths
restriction sites
must be used as the site of insertion (Foreign genetic material cannot be inserted at any chosen or random location on the plasmid )
DNA insertion methods
Microinjection
- Using a fine glass needle to insert the foreign gene of interest into the nuclei of the host organisms cells during the embryonic state
Viral vectors
- Viruses → ability to insert their own DNA in the host genome
risk: they are pathogenic, In order to safely use them as vectors in transferring gene of interest → must first remove the disease causing sections of the virus’s nucleic acids (DNA/RNA)
Ti plasmid insertion:
Gene gun
Crispr - cas9
issues with transgenic organism
ethical: Creating transgenic organisms with human embryos, Unknown what the long term effects may be to humans and animals
environment: Poisoned soil and groundwater
health: Organs from genetically modified animals used in human transplant surgery (xenotransplantation) might transmit viral diseases
types of biodiversity
genetic, species, population
mass extinction
events in the past that have drastically decreased where only organisms with favourable characteristics will survive biodiversity over a short time period
eg. Anthropocene extinction
what can reduce current rate of extinction
Modern biotechnology
conservation
- biorepositories: Storing genetic diversity in facilities
- facilitated adaptation: humans actively introduce adaptive genes or alleles into a population of a species in order to ensure its survival
de-extinction and cloning
- using somatic cell nuclear transfer to bring back extinct species
dis: May have negative consequences on the extant species → eg. asian elephant as a surrogate for the woolly mammoth so they could be endangered themselves
ad: Many species have become extinct due to humans
eg. wooly mammoth
facilitated adaptation
humans actively introduce adaptive gens or alleles into a population of a species in order to ensure its survival
- Individuals from well adapted populations of a species are introduced to a poorly adapted population that is threatened with extinction → introduced beneficials alleles into a population
-Specific alleles from a well adapted population can be identified and directly inserted into the genomes of individuals from a threatened population using recombinant DNA technology
ad: only way to combat extinction
dis: It may fail or introduce more serious problems which can waste time and resources
measuring genetic diversity
Populations can be tested for how many individuals are heterozygous for a specific gene to indicate how many different alleles there are for a gene within the population
-high: healthy
-low: poor genetic variation
measured through allele diversity (avg number of alleles per gene in present population)
sustainability
fossil fuels
- bio fuels produced by biomass such as algae, yeast which is CRISPR edited
plastic
- biological plastics that biodegrades completely (starch, fibre)
pollution clean up
- bacteria to breakdown: oil spills, plastic waste
farming effect on biodiversity
monoculture: decreases human genetic diversity → makes us more vulnerable to diseases
- land clearing
- palm oil
- ireland potato famine: potato blight disease
- selective breeding
