Week 19 Flashcards

Question

Place the steps in the process of plant transformation via particle bombardment in the correct order starting at the top.

Answer 1

1. Gold or tungsten nanoparticles are coated with recombinant DNA 2. Plant tissue fragments are "bombarded" with nanoparticles. 3. Plant tissues are grown in vitro and eventually induced to differentiate and produce a mature plant

Answer 2

Blank 1: environmental | Blank 2: biotechnology

Answer 3

Species A, because it contains more lipids

Answer 4

Blank 1: Biofuels

Answer 5

organic farmers, whose fields are close to transgenic corn, because transgenic crops cannot be certified as organic

Answer 6

the carbon in them comes from atmospheric CO2 that was fixed by plants or algae

Answer 7

Their lipids

Answer 8

They may cause a loss in biodiversity. They may not be safe for human consumption. They may cause allergic reactions.

Answer 9

The difference- Pharmaceutical companies would also be involved in drug development. But they'll be looking at chemically synthesised drug or purifying compounds to make the drug, they are not going to be using living organisms. So if you are using living organisms then that's the basis of Biotechnology.

Answer 10

* Industrial chemicals * Enzymes Industrial biotechnology- Use of living organisms or their derivatives to make industrial products Chemicals Enzymes Vitamins Amino acids

Answer 11

Citric acid from lemons • Citric acid was produced in the UK in 1826 • Lemons were imported from Italy • Calcium citrate was produced and converted to citric acid chemically- mixture of biotech and chemical technology. • 1923 – large scale production using Aspergillus niger began in New York • Citric acid producers in the UK started using A . niger for production- is now a model fungus. Producing citric acid without extracting the calcium citrate from lemons.

Answer 12

Acetic acid- • Fermentation of ethanol or methanol by microbes • 200,000 tonnes produced annually Butanol- • From petroleum or fermentation by Clostridium • Used in plastics, paint, resins and brake fluid • 1.2 million tonnes produced annually Lactic acid-- • Half of lactic acid in Europe is made by microbes • Used as acidifier, preservative and in plastics

Answer 13

Enzymes were traditionally obtained from microorganisms, plants and animals. Amylase (plants and yeast) Pepsin (stomach of pigs and cows) Rennet (calf stomachs) Trypsin; chymotrypsin (pancreas of pigs) Proteases (e.g. papain from papaya and ficin from figs)

Answer 14

Enzymes have many industrial and home uses Pectinases- •needed to break down pectin in manufacture of fruit juice and baby food Proteases- •many uses including in leather tanning Phytases- •added to animal feed to enable digestion of phosphate- so phosphate is not a limiting factor.

Answer 15

* Enzymes have been used in detergents since the 1960s * Subtilisin from Bacillus subtilis * Also used are alkaline proteases, amylases and lipases * Nowadays subtilisin is modified to increase stability and efficacy

Answer 16

* “emersed culture” to produce amylases and proteases from Aspergillus oryzae- this would be used to produce amylases and proteases and various other enzymes. This essentially helps the fungi to grow on straw beds and then the compounds are produced and extracted from these beds. So it wasn't as efficient as a modern culture method. * “submerged cultures'' of A . oryzae in large bioreactors from the 1950s- essentially liquid cultures often in these large bioreactors. Advantages: high yields, cheap, continuous production

Answer 17

Enzyme recycling If enzymes are safe and cheap to manufacture , then they can remain in the end product or be discarded. But what if enzymes are expensive or need to be removed from the end product? Use immobilised enzymes Immobilised enzymes are enzymes that are fixed in some way e.g . in a gel or to a membrane. In this way it will be easy for us to prevent the enzyme from being moved into the end-product and we won't need to keep manufacturing such large quantities of it, so it will reduce production costs. 1) Recyclable 2) Increased stability 3) Absent from end product 4) Lower production costs

Answer 18

Traditionally when we want a source of sweetness we use sucrose which can be manufactured from many different things but normally from sugar cane or from sugar beets. Could also use glucose which can be readily available for many different things. So from grains, from potatoes, from cassava. We could use glucose instead of sucrose. However, glucose is only about 75% as sweet as sucrose so we would need to use more of it. • Glucose isomerase ( converts glucose into its sweeter isomer( a compound with the same chemical formula, but it's got a different configuration), fructose Fructose is twice as sweet as glucose, so if we are producing fructose using glucose isomerase, then we can produce less of it and still have the same amount of sweetness in our products- a cost saving measure. • Glucose isomerase was first isolated from Streptomyces spp . in the 1950 s • 1960s - High fructose corn syrup • Glucose isomerase was expensive to manufacture • Immobilisation was used successfully to increase fructose yield

Answer 19

- -40% - -55%. - -15% - -42%

Answer 20

Soluble form shows you’ve got much larger costs of staff for example, when you are using the glucose isomerase that's soluble, much reduced staff costs when you are using the immobilised enzyme. The enzyme itself is at a much lower cost because it is being recycled and is being recovered and used again.

Answer 21

health ``` Biopharmaceuticals Recombinant proteins Vaccines Antibodies Stem cells Animal models Gene therapy ```

Answer 22

These are proteins that have been altered in some way, genetically modified.

Answer 23

- -100 - -50 - -Insulin - -Blood - -Replacement - -Inhibition - -proteins

Answer 24

First commercially available GM hormone - 1982 • Diabetes - glucose levels are high • High blood sugar • Type 1 - lack of insulin- where it isn't being made probably. • Insulin came from pigs or cows The B and A sections are the bits that will combine together to form insulin. The C is known as the connecting peptide, which needs to be cleaved away to yield mature insulin molecules. The signalling sequence is used to make sure that the hormone is secreted out of the cell. What would normally happen in the production of insulin is you would have this insulin molecule that would be our producer's insulin that would be produced and the signal sequence would be cleaved away. You would then have these disulfide bonds that would form between the a and the B chains and they would make this type of loop. Then you’d have endopeptidase that would cleave this connecting peptide away, that would yield your mature molecule so the B and A chain.

Answer 25

• Clone and express insulin in E. coli • Not simple, needed refining Protein fusing- joining one protein to another and enabling these to be expressed in a bacterial culture. This once done as follows: We needed the gene that encodes the incident molecule, then we need to get this into our vector, or a plasmid and get this into E.coli cultures. mRNA from rat pancreatic cells Reverse transcriptase to make cDNA- to convert mRNA to cDNA. Digest with restriction enzymes Ligate into vector- join DNA into the vector. Allergic reactions to porcine or bovine insulin, so desirable to have E. coli produce human insulin – Humulin Had to tweak sequence using enzymes to modify the protein Also tweaked sequence to prevent clumping when being injected

Answer 26

- -$40 - -pathogen - -Preventative - -ill - -childhood

Answer 27

* First vaccine developed in 1796 by Edward Jenner- Heterotypic * Live cowpox virus against smallpox virus * 20-30% of those infected died * First infectious disease to be eradicated worldwide (1977)

Answer 28

``` DNA RNA Heterotypic- where you are using one species to provide immunity against another. Toxoid Subunit Attenuated Conjugate Inactivated- a killed pathogen ```

Answer 29

- Fragments from the pathogen e.g. viral protein coat or lipids from outer membrane - Developed prior to recombinant DNA technology - Pathogens grown in liquid culture & secreted proteins used in the vaccine

Answer 30

- -Blood - -liver - -proteins - -plasmids - -

Answer 31

Killed pathogen; most common type Salk vaccine for polio; rabies; influenza; Hepatitis A Many pathogens can’t be isolated or cultured in vitro or it’s too expensive Also risk of infection to biotech workers

Answer 32

You have the virus which is being killed in some way and in this case by using heat to denature it and it will be fragmented in multiple different parts. The idea is that enough of the pathogen is still going to remain behind to be used in the vaccine to provoke an immune response in the system.

Answer 33

Live, weakened pathogens that no longer express the toxin gene Sabin vaccine for polio; MMR, tuberculosis, chickenpox, cholera Can be a natural mutant or a GM mutant- removing the toxic gene Could be related virus e.g. cowpox - heterotypic Safer to produce, but need a lot of research to identify toxic gene Risk that attenuated pathogens may revert to pathogenic strain

Answer 34

Sequence genomes to find antigens • Sequence pathogen genomes • Identify genes and clone into expression library • Determine which proteins are responsible for the immune response i .e . are antigens Meningitis B vaccine – Bexsero 2015 • Attenuated Neisseria meningitidis vaccines were ineffective

Answer 35

- -attenuated - -350 - -E.coli - -silicone - -mice - -immune - -protein

Answer 36

Use viral genomes • Can use Vaccinia virus to make new vaccines • Clone genes of interest into a plasmid and insert into Vaccinia genome • Use recombinant Vaccinia virus as a vaccine against smallpox as well as other illnesses e.g . influenza

Answer 37

* Developed for diseases such as rabies , Zika and flu * First one licensed was for Covid-19 (Pfizer) * Dendritic cells take up mRNA delivered in a lipid nanoparticle and produce the antigen protein. They will produce the protein which is there to promote your immune response.

Answer 38

DNA-based vaccines • Add the gene encoding the antigen into a plasmid • Bind the DNA to a charged particle and inject • The DNA will bind with genomic DNA particles and the antigen will be expressed temporarily, triggering a localised immune response • Cheaper to make and easier to store • 2005 - first DNA-based vaccine was produced against West Nile Virus • 2007 - a therapeutic vaccine for canine melanoma

Answer 39

Undifferentiated cells • Can differentiate into specialised cells & replicate to make more SCs • Replenish old cells One stem cell can generate all the cells within the body.

Answer 40

means the level at which they can develop into further cell lines.

Answer 41

Totipotent cells can differentiate into all cell lineages to regenerate a whole organism e.g . in plants and fungi , or embryonic stem cells within the first couple of cell divisions . They can generate both embryonic and extraembryonic cells , such as the placenta . Pluripotent cells are capable of forming all the cell lineages within an embryo , but not extraembryonic lineages e .g . ESC . Multipotent cells have the potential to differentiate into many, but not all , cell lineages e .g . adult stem cells such as HSCs; ISCs

Answer 42

Found in bone marrow Multipotent : replenish red and white blood cells They are found near blood vessels within the marrow “vascular niche” and at the inter face between the bone and marrow “endosteal niche”.

Answer 43

- -Lymphoid - -myeloid - - two - -red - -white

Answer 44

Found in the small intestine AKA crypt base columnar cells (CBCs ) Can differentiate into four cell types: • Absorptive epithelial cells (enterocytes) • Goblet cells • Enteroendocrine cells • Paneth cells

Answer 45

1- Absorb nutrients 2-Secete mucus 3-Digestive hormones 4- Antimicrobial peptides.

Answer 46

Derived from the blastocyst Pluripotent , so they are capable o f forming all the cell lineages within an embryo , but not extraembryonic lineages. Cells can be grown in culture. The ESCs are in demand because they can be grown in culture for multiple years. Then you can add specific growth factors to develop the cell types that you’ll need, things like muscles, nerves, skin, etc.

Answer 47

• Changes in gene expression allow reversion of adult cells into stem cells Depending on the different genes you can switch on and off, you can get them to differentiate into multiple different cell types. • Less controversial as not derived from an embryo (2006) • Not clear if identical to ESCs • Low efficiency of production (0 .1%) • Can cause tumours • STAP cell controversy

Answer 48

``` HSCs are most commonly used (bone marrow transplant) HSCs can also come from umbilical cord blood and there are some circulating in blood Potentially used for: • Leukaemia , lymphoma , sickle cell anaemia , myeloma • Tissue regeneration • Reverse ageing • Parkinson’s • Diabetes • Spinal cord injuries • Replacement for animal testing ```

Answer 49

A knockout mouse is essentially a mouse that’s had a particular gene disrupted, so that its function can be analysed. The reason we might want to do this is so that we can look at the function of a gene in a mouse and then infer that a homologous gene in a human would also have the same function. We can use stem cells in this process. You would make your vector containing your gene of interest- so the gene you would like to be disrupted, you would then insert this into the mouse stem cells, which would uptake this plasmid, uptake this gene and then by homologous crossing over, you would disrupt this gene in the mouse. So you have noe knocked out this gene in the stem cells and then you would add these stem cells into an early developing embryo, where this would continue to develop over the next five or six days. And then you can then transplant this into your mouse. The mice would give birth to offspring. The agouti mouse would end up carrying that transgene.

Answer 50

* Fingerprints * Blood type * DNA technology * DNA Fingerprinting * DNA databases * DNA barcoding * Biometrics

Answer 51

Blood type A, B and O- corresponds with the type of antigen you have Glycolipid antigens A , B and O * O has one fewer carbohydrate * A has N-acetyl-galactosamine * B has galactose

Answer 52

carbohydrate | blood

Answer 53

Blood type A, B and O • Antibodies are made against the A and B antigens but not the O • AA or AO would raise antibodies against BB, BO or AB blood type- if you were to receive blood from a different blood type to you, if you had an a type and they had the B antigen, then you’d essentially by a mounting an immune response against these antigens and also the blood would clump and not be successful. • AA or AO can receive blood from AA , AO or OO, but not BB, BO or AB OO blood group are universal donors , but can only accept OO blood AB blood type are universal acceptors

Answer 54

blood transfusion

Answer 55

Analysis of DNA fragments for identification • Developed in the 1980s at a similar time to PCR • Early method used Restriction Fragment Length Polymorphisms (RFLPs) 1 . DNA was extracted, cut with restriction enzymes and run on gel.- restriction enzyme cuts up various sites. Analysis of DNA fragments for identification 2. A Southern blot was used , where DNA was transferred to a nylon filter 3. Radiolabeled DNA probes were used , which bind to complementary DNA 4. An autoradiograph was generated , where radiation - sensitive film is placed over the blot and DNA bound to the probes appear as bands on the film. 5. The restriction pattern is matched to the victim’s The next step, DNA is run on the Southern blot and in this case you press a nylon sheet across your gel on DNA will be transferred to this nylon filter. You would then incubate this in a probe solution. This would be DNA probes that are complimentary to sections of the DNA sequence. So once the DNA is denatured, these can then bind and you can then generate this autoradiograph. Where the radiation sensitive film would be placed over the blot and the DNA thats bound to those probes would then appear as bands on the film. Then you would be able to analyse them.

Answer 56

* Nowadays , DNA is amplified by PCR and sequenced * Often , minisatellites (VNTRs -Variable Number Tandem Repeats) and microsatellites (STRs - Short Tandem Repeats) are used * Can be run on a gel or visualised by qPCR or sequencing software

Answer 57

Used to identify species At its basis it involves doing a DNA extraction and then amplifying conserved regions of the genome via PCR. then running them on a gel or sequencing them to double-check which species is present. Once you have the sequence back, you can blast them against a national database and then obtain your speech identification.

Answer 58

* Fungi (ITS) * Plants (chloroplast) * Animals (COI) You would have these standardised regions of the genome that you would look at. And they'll be conserved enough within the species so you can just identify the same species but not so conserved that you wouldn't be able to separate out individuals from that species.

Answer 59

* Fish in restaurants * Horse meat scandal * Prey of wild animals * ID of insect larvae DNA barcoding field course • Collect plant and fungal species • ID by morphology • ID by barcoding

Answer 60

• Bioremediation • Biofuels

Answer 61

Clean up waste Bioremediation is the use of living organisms or their products to break down waste and pollutants in the environment * Organic waste from farms, homes and industry threaten soils, drinking water & aquatic ecosystems * Chemical spills, oil slicks, pesticides, heavy metals * Physical clean up is time-consuming and expensive Can search for organisms that can degrade waste or pollution and use these directly. Can genetically modify other organisms to express the relevant genes Uses natural chemical reactions and processes Substances produced are less toxic or harmless e.g. CO2 , water, chloride

Answer 62

This shows you where the source of the spill might be- for example, on the surface of the soil, it could be in the underground, a leak from an underground pipe. Both of these could get into the soil and then into that aquifer, which would split supplying water to homes. Or it could run off into the rivers, lakes in the sea and need cleaning from that. Where the spill, the chemical spill is located, might require a different mechanism in order to clear it up. For example, is in an aerobic environment or an anaerobic environment, you might need to use the correct microbes in those situations.

Answer 63

* Isolated strains of Pseudomonas from contaminated soils | * Contained plasmids encoding genes for degrading organic compounds such as naphthalene , octane and xylene

Answer 64

* Can use metallothioneins to neutralise heavy metal pollutants such as cadmium and mercury * Metallothioneins are found on cell surface and bind to heavy metals , reducing their bioavailability because they cant be taken up by plants

Answer 65

The fungi Phanerochaete chrysosporium and Phanerochaete sordida can degrade toxic chemicals such as creosote , pentachlorophenol , and other pollutants that bacteria degrade poorly. Fusarium oxysporum and Mortierella hyaline can degrade asbestos and heavy metals

Answer 66

■ Disasters – Exxon Valdez in 1989 • Ran aground & released 42 million litres of oil off the Alaskan coast 1 . Clear from surface using skimmers and vacuums 2 . Wash rocks with water 3 . Added fertiliser to encourage growth o f bacteria to degrade • Oil will remain for hundreds of years – Deepwater Horizon in 2010 • Explosion released 600 million litres of oil into the Gulf of Mexico • Oil was removed by various methods • Bioremediation degraded ~50% of the oil released

Answer 67

White rot fungi • Lignocellulose is a waste agricultural and industrial product • Cellulose, hemicellulose and lignin • Many microbes can degrade cellulose and hemicelluloses , but not lignin • White rot fungi can degrade lignin e .g . Phanerochaete chrysosporium • They use peroxidases to break the bonds between phenols in lignin- naturally a white rot fungus that it can degrade.

Answer 68

Recovering valuable metals • Copper, nickel , gold • Many microbes can convert metal products into metal oxides or ores • Useful for recovery of metals from waste solutions from industrial manufacturing processes

Answer 69

* Most radioactive materials kill microbes , but some strains have can degrade radioactive chemicals * No bacterium has been identified that can completely metabolise radioactive elements into harmless products.

Answer 70

Using plants for bioremediation of soil, water and air ~350 plant species naturally take up toxic materials • Poplar, juniper, grasses , alfalfa , Agrostis What usually happens is plants are grown in the soil, they take up the toxic compounds, which could be heavy metals such as mercury, then you can remove the plant and at the same time you’ll removing the toxic compound from the soil. • Sunflower plants removed radioactive cesium and strontium at the Chernobyl nuclear power plant in Ukraine • Water hyacinths remove arsenic from water supplies in Bangladesh and India • GM plants for methylmercury

Answer 71

Biofuel production Biofuel Fuel produced through biological processes e.g. from agriculture. Not fossil fuels such as coal and petroleum from prehistoric matter- renewable. ``` ■ Issues: • Expensive- easier to use petrol • Subsidy dependent • Fuel instead of food? • What to do with the waste products? • What impacts on biodiversity? ```

Answer 72

• Could produce gas from animal dung in small bio reactors. | Successful on a small scale- small scale farmers.

Answer 73

* Sugarcane or maize are often the raw materials used- by producing this you are preventing mounds of sugarcane being dumped into the environment. * Microbes convert sugars into ethanol; production is expensive * Around 14 litres o f sugar residue and 100 litres of water are needed to make 1 litre of ethanol * Fuel additive

Answer 74

* Derived from plant oils & animal fats e .g . palm oil , soybeans * Standalone fuel ; replacement for diesel

Answer 75

Biofuel production Lignocellulose biomass * Agricultural waste products, woody crops , sawdust , household waste or crops grown on land that is unsuitable for food production * Should not require much of water or fertiliser to grow * More sustainable * Still for biodiesel and bioethanol * Less competitive due to difficulties in degrading lignocellulose * Use physical , chemical and biological production methods

Answer 76

Biofuel production Biofuels from algae- growing in culture. * Still under development; algae and cyanobacteria * No competition for land use; oils are easily refined into diesel * Easy to genetically manipulate algae to produce ethanol and butanol * Can also make biogases such as biohydrogen and biome thane * Algae can produce 10 x the output of traditional biofuel feedstocks * Disadvantage: need a lot of fertilisers

Answer 77

3% of UK fuel is from biofuels • 419 million litres of biofuel in 2017 – 179 million litres sustainable • 69% of sustainable biofuel was made from a waste /residue feedstock • 38% of biodiesel was used cooking oil from the UK • 23% of bioethanol came from maize grown in the Ukraine A greenhouse gas saving of 80% compared to fossil fuels

Answer 78

• Plant transformation • GM crops

Answer 79

Green biotechnology: use of crop plants and agricultural systems • Humans have modified plants for thousands of years • Traditional breeding techniques , plant propagation , mutational breeding (1920s) • Genetic modification – GM/ transgenic /biotech crops

Answer 80

Agrobacterium tumefaciens Tool used in molecular biology- • Plant pathogen- we are exploiting its natural ability to infect plants and we are using this in molecular biology. • Causes Crown Gall (1907)- caused because of the oncogenes and its inducing the plant to produce excess auxins and cytokinins, which causes the plants to grow uncontrollably causing these galls. But its also introducing genes for itself. So these Opine genes which are what the bacterium would use the products of to feed on. They do this because they have a really large plasmid. • Induces plant to produce excess auxin & cytokinin • Galls contain opines synthesised by genes on the Ti plasmid- this plasmid contains not just these oncogenes and the operine genes but it also contains genes for virulence. So this is how the pathogen would be infecting the plant, contains an origin of replication so that it could replicate in the bacterium. Theres transfer genes for moving between individual bacterium. And the catabolism gene so that it can actually process food. In the natural sense agrobacterium would infect dicots and it would transfer its T-DNA, which is anything between the left and right border, it would transfer this into the plant. Then the rest of the plasmid will be left behind in the bacteria. But in molecular biology we can exploit this by modifying the TI plasmid and introducing R genes of interest in-between the left and right T-DNA border, and then agrobacterium will transfer these genes into plants. - mainly used for dicot transformation.

Answer 81

Other plant transformation methods. Gene gun or particle bombardment • Gold particles are coated in the DNA construct to be introduced , then they are fired at target cells • Cells are then regenerated into whole plants Coating you gold or tungsten particles in your target DNA. then you are firing this into the plant. In the case of the gene gun, this can be fired directly into leaves. Firing the DNA particles with your gold into the leaf. And eventually some of it will hit its target, will go in the cells and then it would make its way into the nucleus with the DNA unwind, and transcription and translation would continue as normal. Can select the generated plant and regenerate whole plants in the same way.

Answer 82

GM crops ▪ Also called biotech or transgenic crops ▪ First commercial GM crops in 1994 ▪ Now, four GM crops dominate global production: Soybean (50%) , Maize (31%) , Cotton (13%) , Oilseed rape (4%) GM crops are grown in 26 countries worldwide 18 million growers ~190 million hectares of land $18 billion annually

Answer 83

• Herbicide tolerance • Insect resistance

Answer 84

* RoundUp * Glyphosate blocks amino acid synthesis - if its sprayed on the plants then the AA synthesis pathway cant continue so you cant make proteins and the plant will die. * Introduce a mutant EPSPS gene from Agrobacterium tume faciens (aroA); glyphosate cannot bind * Plant is now resistance to glyphosate

Answer 85

The way in which we actually transform these plants to be resistant to glyphosate is that you introduce a mutant EPSPS gene and in this case it's called aroA its taken from Agrobacterium tumefaciens. So our plant pathogen that we are using for plant transformation, taking this mutant gene, with this gene glyphosate can’t bind to it. So what this means is that a plant that has this gene is resistant, or tolerant because it still has its native gene that would not be tolerant to the herbicide. It would have two copies, one is native gene that would allow it to be killed by glyphosate and then this mutant gene, where glyphosate can’t bind to it, so the plant can continue to produce its AA, produces proteins. The crop that has this gene will be able to persist.

Answer 86

Bt toxin • cry genes from the soil bacterium Bacillus thuringiensis • Toxic protein , which solubilised when ingested by insects • Binds to epithelial cells within the digestive tract and creates holes • Insects die within a few days • Spray plants with it in organic agriculture

Answer 87

Bt toxin is a toxic crystallised protein and it’s generated by the cry protein from a slow bacteria called Bacillus thuringiensis. When this toxic protein is ingested it will bind to receptors in the insect's guts and it will cause pores to form in the gut. The cell contents will leach out on the and the insect will die in a few days. Its not just in GM crops that this is used, you can also spray crops just with this crystallised protein in organic agriculture, and it wouldn't be classed as a pesticide. With a GM crop its only going to be expressed in the plant itself. So it's not going to be in the soil, maybe to be ingested by other insects that actually arent a pest, it's only going to be impacting those that are actually chewing on the leaf.

Answer 88

Herbicide tolerance • Glufosinate • Bromoxynil • Dicamba Virus resistance • Crops such as potato, squash, sweet pepper, papaya and plum • Cucumber mosaic virus (CMV); Watermelon mosaic virus (WMV2) ``` Quality traits (second generation) • Drought resistance • Lysine biosynthesis • Phytase maize • Photosynthetic genes • Golden rice ```

Week 19 Flashcards

(113 cards)