HSC Biology Module 6

What are the benefits of using genetic technologies in agricultural, medical and industrial applications?

agriculture >> creation of crops and livestock with favourable traits, crops which are pest resistant (decreased impact on environment), increased food security medicine >> creation of improved treatment methods (i.e. insulin for humans), treatment/cures of genetic diseases, methods for pre-emptive diagnosis industrial >> increased speed of chemical reactions, biofuels, bioenergy

What is a mutagen?

an agent that causes genetic mutation.

What may be the changes to the Earth's biodiversity due to genetic techniques?

creation of monocultures, horizontal gene transfer, loss of diversity, loss of variation

What are the three main types of mutagens?

electromagnetic radiation, chemicals and naturally occurring mutagens (called infectious agents in the diagram)

Evaluate the effect on biodiversity of using biotechnology in agriculture

positives: insect and herbicide resistant, maximum use of restricted land, survival against increased environmental pressure, potential to increase biodiversity through transgenics negatives: pose a threat to biodiversity, ability to out-compete non-GMO crops, horizontal gene transfer into native ecosystems

What is whole organism cloning?

the creation of a new molecular organism that is genetically identical to its parent organism E.G. Dolly the sheep 1997

Assess the significance of 'coding' and 'non-coding' DNA segments

'coding' DNA is used for protein synthesis and hence affects cell function. 'non-coding' DNA can be further described as 'junk DNA', enhancers and silencers, promoters, introns and terminators and play a role in

Assess the influence of social context on a range of biotechnologies

+ >> address social inequity, increase dialogue between communities and scientists, reduce environmental footprint, GM crops require less tillage - >> may increase socioeconomic disparity, lack of consistent regulation internationally

Assess the influence of cultural context on a range of biotechnologies

+ >> food is essential part of cultural practices, provide a tool for preserving important foods, preserve agricultural practices in the face of climate change - >> traditional farming practices may be eradicated, lack of scientific communication - mistrust among communities - rise in anti-science beliefs, backlash from religious groups on ethical issues

Assess the influence of economic context on a range of biotechnologies

+ >> stimulates agricultural economy, tools to grow crops easier, may improve desertified ecosystems - >> potential monopolisation, exploitation of patents, may cut small-scale farmers out of the market

What are the positive aspects (social and ethical implications) of biotechnology?

- Meeting the growing needs of society >> being able to harness biological tools to invent new, creative solutions (E.g. meetings the UNs Sustainable Development Goals) - Genetic Diversity >> Create new arrangements of genes, new allele combination - Open-Source Information >> Creation of public databases allows for the growing amount of biological knowledge to be shared

What are the negative aspects (social and ethical implications) of biotechnology?

- Ownership >> Intellectual property constraints may become prohibitive to progress (e.g. zinc fingers technology) - Commercial Implementation >> Biotech Monopolies >> Companies with vast resources may dominate the market, and drive up the prices of products to the detriments of those who need the tech most - Regulation >> Governments - can they strike a balance between safety and innovation? threat of biohacking?

Describe the process of artificial insemination

1. Semen is removed from male using an artificial vagina 2. Semen is divided into semen straws, and frozen in liquid nitrogen for long-term storage and transportation 3. Semen straw is placed in an artificial insemination 'gun' 4. The gun is inserted into the vagina to the cervix and semen is deposited

Describe techniques and applications used in recombinant DNA technology

transgenesis >> introduction of genetic material (DNA) from one organism into another's. Performed so that the organism exhibits a new trait gene sequencing >> determining the nucleotide sequence of DNA (Sanger method - gel electrophoresis) gene therapy >> the correction of genetic disorders by introducing normal functioning genes into cells ELISA >> an analytical tool used to detect the presence of antigens in a liquid sample CRISPR-Cas9 >> a gene editing tool where point mutations are accurately introduced into genomes

Describe the process of artificial pollination

1. The stamen of a flower is removed 2. Pollen from the stamen is dusted onto the stigma of either the - Same flower - Another flower of the same species - Flower of different species (cross-pollination)

What is a somatic mutation?

A genetic alteration which cells acquire, which may be passed on to daughter cells by cell division (mitosis in humans) and only affect a certain area of the organism. A somatic mutation will not alter genetic composition of other cells in the body and IS NOT passed onto offspring. E.G. skin cancer

What is a germ-line mutation?

A mutation in germ cells (gametes) which CAN BE passed onto offspring during fertilisation. It depends if the mutation happens on both chromosomes (e.g. both of chromosome 21) or on only one chromosome as to whether the child is a carrier or affected. E.G. Sickle cell, colour blindness

What is a mutation?

A permanent alteration to the nucleotide sequence of an organism's genome

What types of chromosomal mutations are there?

Deletion = section of a chromosome is removed Inversion = section of a chromosome is inverted and re-inserted Translocation = when a portion of a chromosome is moved to a non-homologous chromosome (e.g. 21 to 22) Duplication = when a section of a chromosome is doubled

What is an example of a disease as a result of a chromosomal mutation?

Down syndrome - "nondisjunction." Nondisjunction results in an embryo with THREE copies of chromosome 21 instead of the usual TWO. Prior to or at conception, a pair of 21st chromosomes in either the sperm or the egg fails to separate.

How does fertilisation and meiosis cause mutation and thus genetic variation?

Fertilisation is when two gametes (sperm + egg) come together to form a zygote. The random selection of gametes as well as the interaction of dominant and recessive genes leads to genetic variation. Meiosis is the process of cell division resulting in the production of gametes. Mutation may occur during DNA replication. Genetic variation may occur due to crossing over, random segregation and independent assortment.

What is gene flow (migration)?

Gene flow is a mechanism of VARIATION in which individuals from one species moves to a population of another species. This may happen due to transport (a boat, a bee), an ice age etc. which enabled physical mixing of one isolated species into the other. This introduces a new allele into population improves variation. E.G. a bee carrying pollen from one flower population to another.

What is genetic drift?

Genetic drift is a mechanism of CHANGE which describes a RANDOM change in the gene pool of a population. E.G. a natural disaster that wipes out a portion of the species (i.e. a volcano erupts and kills all the red beetles on one side of the volcano only leaving green beetles)

How does electromagnetic (ionising) radiation cause mutation?

It interferes with DNA molecules causing hydrogen bonds within DNA structure to break thus changing the chemical composition. This results in deletion or rearranged nucleotides. E.G. UV rays from sunlight, x-rays for medical uses.

What are the potential benefits for society of research using genetic technologies?

Medical >> vaccines, antibiotics environmental >> bioremediation, agricultural (GMOs) industrial >> renewable energy sources, biofuels

What is the effect of mutation in the non-coding region?

Mutations in the: junk region = little significance enhancers and silencers = genes being under or over expressed. promoter region = prevent the gene from being transcribed intron region = effect the splicing of genes. terminators = incorrect, elongated mRNA sequence

What is gene cloning?

Occurs at a cellular level and involves producing identical copies of one gene E.G. golden rice

What are transgenic organisms?

Organisms which contain at least one gene from another species

What is an example of a disease as a result of a point mutation (SNP)?

Sickle cell anaemia - SUBSTITUTION of A to T resulting in the codon GTG (valine amino acid) instead of GAG (glutamic amino acid).

What types of point mutations are there?

Substitution = when one nucleotide switches with out for a different one Frameshift (insertion/deletion) = shifts the whole sequence up or down Silent = mutation has no effect on codon production or protein Missense = mutation affects one codon, introducing new amino acid into protein sequence Nonsense = introduced premature STOP codon, dysfunctional protein

What are future directions for the use of biotechnology?

Synthetic biology >> combining engineering principles with biological tools (a field of science that involves redesigning organisms for useful purposes by engineering them to have new abilities). E.G. Golden rice - variety of rice produced through genetic engineering to biosynthesize beta-carotene, a precursor of vitamin A. Tackling micronutrient malnutrition in the Global South.

How do chemicals cause mutation?

They can either break hydrogen bonds in DNA or affect processes in DNA repair and replication. E.G. carcinogen (cigarettes), cleaning products, processed foods and preservatives.

How do naturally occurring mutagens/infectious agents cause mutation?

They can insert their own DNA into an organisms existing cells and 'take over' (viruses E.G. HPV) or they can induce inflammation which can reduce efficiency of DNA repair systems (bacteria E.G. helicobacter)

What is chromosomal mutation?

a mutation which changes or affects a long segment of DNA/ whole chromosomes

What is a point mutation?

a mutation which only changes/effects one (or a few) nucleotides within a gene sequence