genetics biology test

GMO Bt corn

GMO Bt corn

genetically modified corn in order to produce a protein toxic to certain bugs

Benefits of GMO Bt corn

-safer for environment

-saves farmers money/labor

-more money and ends hunger

-doesn’t harm monarchs

-easier and precise way to make changes

-more cost-effective

-contributes to sustainable food supply

Risks of GMO Bt corn

-harm on other organisms and other environmental factors

-multiple effects on the organism

-resistance in the insect from being exposed to it a lot

-problems/genes can spread to other plants

-food allergies

-long term issues

Lysis

the process of breaking cells apart

lysis- mechanically

crushing material to start breaking up the cell membranes and nuclear membrane

lysis- chemically

detergant- polar and nonpolar components break apart membranes through different attractive forces

salt-used to start clumping dna as different ions are attracted to negatively charged dna

cell lysate

forms because of lysis

-mixture of cellular components (dna, carbs, proteins, lipids, etc)

lysis procedures

1. crush small sample of wheat germ, add 1.0 ml (20 drops) of distilled h20, swirl

2. add 1.0 ml (20 drops) of 25% liquid dishwashing detergant solution, swirl

3. add 1.0ml (20 drops) of 8% sodium chloride solution, swirl

lysis ingredients

-fingers

-1.0 ml distilled water

-1.0 ml of 25% liquid dishwashing solution

-1.0 ml of 8% sodium chloride solution

precipitation procedures

1. hold tube at slight angle, add 2.5 ml (50 drops) of 95% ethyl alcohol to form layer over mixture

2. gooey mass of dna go out of mixture and in between layer of alcohol and wheat germ mixture

precipitation ingredients

-2.5 ml 95% ethyl alcohol

Base pairs

-adenine + thymine (AT)

-guanine + cytosine (GC) (3 bonds)

purines

-adenine

-guanine

-double ringed

-bigger

pyrimidines

-thymine

-cytosine

-single-ringed

bonds in sugar phosphate backbone

covalent bonds- for strength and structure

bonds in between bases

hydrogen bonds- it can easily split during replication

Erwin Chargaff

observed that the percentage of adenine equals the percentage of thymine, and cytosine and guanine

hierarchy of dna

-nucleotides

-genes

-chromatin

-chromosomes

-nucleus

monomer(subunit) for dna

nucleotides (a,t,c,g)

dna

used for instructions for the organisms to perform actions and instructions for making proteins

histones

-condense and create chromosomes with chromatin into a condensed shape

-allows it to fit tightly in the nucleus

genome

the complete sequence of an organisms genetic material

genomics

the study of this sequence and its organization

steps to analyzing a genome

1. select organism

2. isolate dna

3. sequence dna

4. map the genome

history of genomics

-1972: walter fiers at university of ghent in belgium completed the first sequence of an individual gene in an rna virus

-1976: fiers sequenced complete gene

-1977: frederick snager (uk) and allan maxam and walter gilbert (us) developed sequencing methods to allow sequencing of longer stretches of dna

-1977: sanger published the first complete sequence of dna viral genome

alternative energy (genomics and sustainability)

hope to find ways to easily break down cellulose to produce ethanol for biofuels

ecosystem biodiversity (genomics and sustainability)

construct a genomic profile of samples and chart the biodiversity and dynamics of ecosytems of the oceans

evolution (genomics and sustainability)

compare species and organisms of the same species to investigate evolutionary relationships

human health (genomics and sustainability)

identify individuals risk for a disease and could help develop therapies and cures for various conditions

dna replication

the process by which dna is copied in a cell before a cell divides by mitosis, meiosis, binary fission

hypothesis 1: conservative

original strand ‘unzips’ down center, nucleotides link together and make copy of each strand, new strand unbinds from original, original strands bind back together

hypothesis 2: semiconservative **

original strand ‘unzips’ down center, nucleotides link together and make copy of each strand, dna formed contains one old and one new strand

hypothesis 3: dispersive

original strand ‘unzips’ down center, nucleotides link together and make copy of each strand, original pieces and new pieces randomly join in combinations

steps of dna replication

1. enzymes called helicases seperate dna strands by breaking hydrogen bonds between bases, the y shaped region results when the two strands seperate (replication fork)

2. enzymes called dna polymerases add complementary nucleotides (freely floating in nucleus) covalent bonds form and hydrogen bonds form between bases

3. polymerases finish replicating and fall off, result is two seperate and identical dna molecules

-works from 5’ to 3’

mutations

a change in the nucleotide sequence of a dna molecule

helicase

unzipping enzyme

polymerase

replicates dna molecules

primase

place primers so polymerase can figure out where to go to start

ligase

helps glue dna fragments together

gene splicing

a process using recombinant dna technology to join, by attachment or insertion, a dna segment from one source to a dna segment from another source

recombinant dna

dna in which one or more segments or genes have been inserted either naturally or by laboratory manipulation, from a different molecule or from another part of the same molecule, resulting in a new genetic combination

types of genetic modification for modifying bacteria for biofuels

insert gene from cellulose digesting bacteris into e. coli which is a bacteria that grows well and produces commercial ethanol

benefits for modifying bacteria for biofuels

-alternative fuel to gasoline (solution to global warming)

-less cost and chemical waste than with other biofuel production

risks/concerns for modifying bacteria for biofuels

-not enough safety testing done

-unintended consequences on human health/environment

-gene transfer/ecological impacts if released to environment

current status of research for modifying bacteria for biofuels

-trying to modify yeast to produce biofuels

-gm e coli to produce fuels with longer carbon chain that can store more energy

-gm e coli to produce biodiesel

other solutions for modifying bacteria for biofuels

-make chemical processes more efficient in breaking down plant matter

-selective breeding of microbes to improve fuel quality or weaken plant cell walls

interphase

-not part of mitosis (time between cell division) (G1. S, G2)

-cell doing normal activities (G1, G2)

-dna in chromatin and duplicates to get ready for mitosis (s)

-centrioles replicate

prohase

-chromatin condenses, become visible, sister chromatids paired at centromere

-nuclear membrane breaks down + gone by end

-centrioles form spindles + move to poles

-spindle fibers attach to chromosomes

metaphase

-sister chromatids are lined up down the middle by spindles

anaphase (away)

-sister chromatids seperate at the centromeres

-each chromatid heads to opposite poles of the cell

telophase/cytokinesis

-new nuclear membranes form around dna

-chromosomes uncoil back into chromatin

-cytoplasm begins to pinch in (cleavage furrows), cell walls form (plant)

-resulting in two identical daughter cells from parent

sister chromatid

identical copies of a chromosome

centromere

complex of proteins attached to dna holding the sister chromatids together

gene

segment of dna that codes for proteins

differences: plants vs animal

-plant cells dont have centrioles

-new cell wall forms instead of pinching in

-divide slower due to reforming cell wall

diploid cell

a cell containing two copies of each chromosome

cancer

-cells that divide too frequently, not regulated/controlled, takes away nutrients from healthy cells

-appears because of genes, toxins, radiation, or uv light, excessive growht turns into tumor

checkpoints

g1- checks if cell is grown enough/damaged/enough resources

g2- checks if dna was replicated correctly back in s phase

m- makes sure chromosomes are aligned properly or havet lost chromosomes

type of genetic modification for fast growing salmon

-inserting a growth hormone gene into salmon

benefits for fast growing salmon

-increase growth rate of gm fish so they can be sold 4 times faster

-to grow fish faster while spending less money

-more supply for consumer, more money for seller

-reduce environment impact

risks/concerns for fast growing salmon

-if they escape from their nets they could breed with wild salmon

-they eat the same amout as wild salmon, they would not out-eat wild fish if they escaped

-wild females mate with larger males

-gm fish offspring don’t survive well

-deplete wild fish population

current status on research for fast growing salmon

-computer model to see if they were released into 60,000 wild fish

-investigate possible damage gmo to wild population

-research modifying other fish (catfish/talapia)

other solutions for fast growing salmon

-farm non gm salmon

-prevent escapes

-make sterilization 100% effective