AS91607 (Bio 3.7)

About

Learners investigate how humans have manipulated the genetics of organisms to benefit themselves and what are the biological implications of these artificial selections. Learners to write a scientific report on genetic manipulation.  Achievement Standard 91607(Bio 3.7) requires you to select two manipulations from the following:

• Selective Breeding

• Whole organism cloning

• Transgenesis

• Investigation and modification of the expression of existing genes

For each manipulation, you will need to research:

• the techniques and /or processes used in the manipulation 

• the biological implications of the manipulation in relation to a particular case study/scenario.

Techniques and/or processes used in the manipulation

Examples include:

• recombinant DNA using restriction enzymes and ligation ( used in transgenesis)

• genome analysis ( used in modern selective breeding)

• PCR ( used to amplify DNA)

• electrophoresis (used in DNA sequencing)

• CRISPR ( used in gene editing)

You need to be to explain in your own words both how and why the manipulation is carried out. Your explanations should be supported by appropriate annotated diagrams. For example, in the case of traditional selective breeding, this might include punnett squares, and for transgenesis, this might include a flow diagram showing the processes involved in producing recombinant DNA.

Biological implications of the manipulation in relation to a particular case study/scenario

The implications may include impacts on:

• ecosystems

• genetic diversity

• health or survival of individuals

• survival of populations

• evolution of populations

Genetic Transfer - Introduction

Selective Breeding has been used by humans to improve livestock and plants since we changed from hunter-gatherer to a settled farming-based lifestyle and began domesticating animals and cultivating crop plants over 10000 years ago. Selective Breeding was the first example of human manipulation of genetic transfer and is still a common practice today with both commercial and hobby breeders. In recent times, whole organism cloning and transgenesis have become important genetic manipulations in our attempts to continuously " improve" our livestock and plants.

https://angusnz.com/why-angus/history-of-angus/

Biotechnological Techniques used in genetic transfer

There are many different biotechnological techniques that may be used in modern manipulations of genetic transfer. You will need to select the ones appropriate to any case study you use in your investigation; it may be necessary to research and provide more detail of the specific techniques than that provided here.

Genome analysis and DNA sequencing 

The genome is the complete complement of genetic material in an organism. the size of the genome and the number of genes vary greatly between species and do not necessarily relate to the size and complexity of the species - eg the mouse genome contains 30000 genes while the human genome has about 25000 genes.

Genome analysis involves determining the locus and base sequence of all of an organism's genes. Genomes are continually being determined. During genome analysis, when an individual gene and its alleles have been identified and located:

• individuals with the desired gene/allele can be used in selective breeding programs to increase the chances of offspring with the desirable gene/allele being born.

• the desirable gene/allele can be extracted and cloned, a cloned gene/allele is then used to create a transgenic organism that has the desirable trait.

• the gene can be subject to gene editing- using the technique known as CRISPR, an undesirable or mutated gene/allele can be removed and then replaced by a desirable or normal version.

Chromosome mapping

Chromosome mapping determines on which chromosome and at which locus a gene occurs. To locate the genes and sequence their DNA, the DNA in each chromosome is analyzed.

Restriction enzymes, plasmids and DNA ligase are all used in the production of recombinant DNA. Making recombinant DNA is an essential technique in producing transgenes and transgenic organisms.

DNA in each chromosome is analyzed as follows:

• the DNA is cut into fragments of varying sizes ( up to a million bases) using restriction enzymes.

• each fragment is inserted into a plasmid vector using DNA ligase.

• recombinant plasmids are taken up by bacteria and the many copies produced become a clone library.

• genetic markers occur at regular intervals along each chromosome: their location in the DNA fragments is found using PCR.

• gel electrophoresis separates different sized fragments; overlaps between the fragments (determined by the genetic markers) give an initial map of the chromosome

• large fragments are further cut up into smaller fragments and cloned to form a subclone library.

• the small fragments have their DNA sequenced using gel electrophoresis.

• overlapping sequences are analysed by computer and a map of the complete chromosome, locating the genes and obtaining their base sequence, is determined as each large fragment is sequenced.

Genome Analysis will allow researchers to do a number of things, including the following

• find the locus and base sequence of genes that cause various disorders or predispositions to disorders - eg cancers, alcoholism, heart disease, embryos can be screened (PIGD - pre- implantation gamete diagnosis) and those with a genetic disorder are either not implanted or aborted. Adults may be able in the near future to be treated with gene editing to replace a "faulty" gene/allele with a gene/allele that functions normally.

• identify the locus of marker genes.

• design drugs using knowledge of protein structures rather than using trial and error.

• Compare mouse and human genomes to allow for more accurate identification of the causes of diseases in humans - human and chips have very similar genomes but differing susceptibilities for common diseases such as cancer.

• Map the degree of genetic relationship within a taxonomic group and establish evolutionary lineages.

• map the degree of genetic relationship within a taxonomic group and establish evolutionary lineages.

• Map the degree of diversity within a group/population/species; this can be used in future management programs for endangered species, including selective breeding eg kakapo.

• Identify genes that confer resistance to disease in commercially important plants.

DNA Sequencing 

DNA sequencing determines the order of bases in a DNA molecule. It is essential in analyzing a genome. Because of the huge number of bases in the genome of any organism, the development of automated sequencing was necessary to make projects such as the Human Genome Project ( HGP) possible. Automated sequencing, based on the manuel Sanger method of interrupted DNA replication, uses gel electrophoresis to sequence up to 600 bases at a time ( a different fluorescent dye color is used to identify each of the four bases.) This also allows for only one lane of the gel rather than four as in manual sequencing. Computers interpret the data on the gel and print off the sequence of bases. The large molecule of DNA to be sequenced is cut into fragments of varying lengths using restriction enzymes, the fragments are separated using gel electrophoresis, and then each DNA fragment is replicated using polymerase chain reaction (PCR).

PCR is carried out by DNA primers being added to the DNA fragments to provide a starting sequence; then DNA polymerase is added: then free nucleotides, some of which are modified and labeled with dye, are added. The modified nucleotides ( nucleotide analogues) terminate DNA replication when they bond to their base pair. With very large amounts of DNA, by chance, each nucleotide will at some time pair with a dyed "terminator" nucleotide which stops DNA replication at that point, This will give the position of that base in the sequence when the gel electrophoresis is analysed.

DNA produced in PCR is washed and dried to produce only single-stranded complementary DNA, which has a dye-labeled terminator nucleotide at the end of each piece. Gel electrophoresis now separates these dyed pieces.

This technique can be used for sequencing genomes, locating recognition sites for restriction enzymes, analyzing genetic relationships, and detecting genetic disorders.

29/03/21

Presentation of slides.

Complete pages 72 and 75 of SciPad

Medical certificate ; Unable to attend school for 3 days- Local Doctors Dawson. RN

26/03/21

Complete  pages 70 and 71 of SciPad

Do education perfect task

https://www.educationperfect.com/app/#/dashboard/homework/4341384 

Watch the video on GMO

https://youtu.be/vribRyVQ6G8

22/03/21

Completion and discussion of pages 66 to 69 of SciPad.

Watch Videos

Cloning

https://1drv.ms/v/s!Ar0GnjwSvQmhh6kV1v2WXqNKKPqyFg?e=ZWxIdB 

Genetic Technologies

https://1drv.ms/v/s!Ar0GnjwSvQmhh6kXdUdtqQhQ0-rFqw?e=PvepLi 

18/03/21

Complete the education perfect task assigned. It is suppose to take  approximately 1 hour 30 minutes.

1. Enzymes in Biotechnology

2. Gel Electrophoresis

https://www.educationperfect.com/app/#/dashboard/homework/4294371 

12/03/21

Watch video on applications of Biotechnology. Class discussion on Selective breeding and method of selective breeding. Discuss issues with selective breeding. Complete page 60 and 61 of SciPad

Have read through the the following document.