1. History of Life & Gene Technology
Miss Colabelli

2. Directional Selection
An extreme phenotype becomes the favorable adaptation
Occurs when the environment changes or species migrate
The new environment favors the extreme conditions
Ex: Long neck of giraffes

3. Stabilizing Selection
Occurs when the average phenotype is the favorable adaptation
Extreme phenotypes are unfavorable
Most common type of natural selection

4. Disruptive Selection Very rare
The average phenotype is unfavorable while the two extreme phenotypes are favorable
Creates two subpopulations

5. Biogenesis
Biogenesis is the principle that all living things come from other living things
Spontaneous generation is the belief that living things arise from non-living things
Back in seventeenth century this was the explanation why maggots arise from rotten meat and fish appear in ponds

6. Francesco Redi
Italian scientist ( ) that noticed and described the different forms of flies
Observed maggots turned into oval cases and flies emerge
Also observed maggots appear where adult flies landed
Created an experiment to prove his hypothesis that flies emerge from maggots

7. Francesco Redi’s Experiment
Control group
The jars were exposed to the environment and not covered
Experimental group
Jars were covered with cloth so air can flow through, but organisms cannot enter or leave
Jars were set up with meat inside and allowed to rot

8. Francesco Redi’s Experiment
Results
The uncovered jars that were exposed to flies had maggots growing that eventually turned into flies
The covered jars did not have any maggots or flies inside

9. Lazzaro Spallanzani
Italian scientist ( ) that used microscopes to observe microorganisms that could explain biogenesis
At this time, it was believed that “vital force” was how microorganisms arise from the air
Hypothesized that microorganisms formed from pre-existing microorganisms
Created an experiment to test his hypothesis

10. Lazzaro Spallanzani’s Experiment
Boiled clear, fresh broth until the flasks filled with steam
Control group
Flask was remained open during experiment time
Experimental group
Flask was immediately covered before cooling so not to allow air or bacteria to enter

11. Lazzaro Spallanzani’s Experiment
Results
The uncovered flask (control group) became contaminated with microorganisms when air entered
The experimental group flask did not have any growth
Scientists believed that boiling the broth killed the “vital force” and still continued to believe spontaneous generation

12. Louis Pasteur
French scientist ( ) created an experiment to answer objections of Spallanzani’s experiment
Made a curved neck flask that allowed air into the flask, but prevented microorganisms to enter

13. Louis Pasteur’s Experiment
Started the experiment by boiling broth in the curved neck flask to kill any microorganisms inside
Left the flask to sit for one year – the broth was still clear
After a year, the neck of the flask was broken
Results
After one day being exposed to the air, the broth became contaminated with microorganisms
These results provided evidence for biogenesis and that spontaneous generation was not possible

14. Alexander Oparin & John Haldane
Soviet and American scientists that were able to determine the inorganic compounds found in the early atmosphere
They believed it contained
Ammonia (NH3)
Hydrogen gas (H2)
Water vapor (H2O)
Methane (CH4)

15. Stanley Miller & Harold Urey
American scientists that created an experiment to explain how inorganic compounds that existed on Earth created our known atmosphere
Set up a chamber containing gases and allowed them to circulate with electric shock
Results
After going through experiment the end results were organic compounds that make up the modern day atmosphere

16. Formation of Earth Earth’s Age
The estimated age of the Earth is 4.5 billion years old
Scientists are able to explore the surface and its layers to study its geology and determine age

17. Formation of Earth Half-life Carbon-14
The length of time it takes for one-half of the same size of the isotope to decay to a stable form
Carbon-14
All living things contain the isotope Carbon-14 in their cells
As they die, Carbon-14 decays into Carbon-12 at a known rate that scientists can calculate and determine the age of the organism
Organisms that are much older, scientists use different isotopes

18. Origin of Heredity First cells Chemosynthesis
The oldest known fossils that are thought to be cells are the size and shape of some living bacteria
Scientists believe that RNA was the first nucleic acid on Earth
Chemosynthesis
Archaea – related group of organisms that can survive under harsh conditions
Chemosynthesis – when CO2 serves as the source of energy as well as inorganic molecules like sulfur

19. Origin of Heredity Photosynthesis & Aerobic Respiration
The ability for organisms to use inorganic matter and create oxygen gas
Cyanobacteria – most likely the earliest bacteria that created oxygen gas as a byproduct and release it into the atmosphere
After billions of years of oxygen gas forming and filling the atmosphere, O atoms reacted with O2 to form O3 which is our ozone
Without our ozone the UV light from the sun would damage our DNA and life could not have come to exist

20. The First Eukaryotes Eukaryotes Endosymbiosis Larger than prokaryotes
DNA is organized into chromosomes
Contain cytoskeleton and nucleus
Endosymbiosis
Theory that modern day organelles were engulfed by ancient eukaryotes and later became part of the cell’s function
Ex: chloroplast and mitochondria (contain their own DNA)

21. Gene Expression
Genome
Our complete genetic information

22. Selective Breeding
When humans allow only those organisms with wanted characteristics to produce the next generation
Hybridization
Crossing dissimilar individuals to bring together the best of both organisms
Inbreeding
Continued breeding of individuals with similar characteristics
Ex: breeds of dogs

23. Increasing Variation Bacterial Polyploid plants
Using radiation and chemicals to bacterial cultures, we can make many strains of bacteria
Ex: oil-digesting bacteria raised to clean up oil spills
Polyploid plants
Being able to make larger and stronger crops

24. Cutting DNA Technology that cuts long strands of DNA
Biologists use restriction enzymes in order to cut the DNA
Biological scissors
Restriction enzymes can recognize specific sequences and only cut in certain areas of DNA

25. How to Make DNA Copies Process called PCR (Polymerase Chain Reaction)
Technology where a small DNA sample can be amplified to many copies for analysis

26. PCR Steps
1. Add sample of DNA, DNA polymerase enzyme, free nucleotides (to make new strands with) and heat sample
The heat will act like helicase and separate the strands of DNA

27. PCR Steps
2. Cool sample down so primers can be added to DNA template strands

28. PCR Steps
3. DNA polymerase attaches to primers and adds nucleotides to rest of DNA template strands

29. PCR Steps
4. Two new strands are made  repeat process until enough DNA sample

30. Recombinant DNA Genetic engineering: changing a genome of living cell
Recombinant DNA: When you combine two or more DNA strands from different organisms

31. Cloning Clone Clones can be created by inserting DNA into vectors
Exact copy of DNA, a whole cell or an organism
Clones can be created by inserting DNA into vectors
Vectors are organisms that are replicate itself
Ex: bacteria, yeasts

32. Cloning
1. Egg cells are extracted from one organism and the nucleus is removed
Nucleus removed because the DNA of the organism we want needs to fuse into the egg
Cells from organism we wish to clone are removed

33. Cloning
2. Desired organisms cell is placed next to egg cell and electric shock fuses the two cells into one
This triggers the new embryo to begin to divide and develop

34. Cloning
3. Developing embryo is implanted in a surrogate mother and after incubation period is over, a new baby organism is born with the exact same genetic information as original organism

35. Genetically Modified Crops
Using recombinant DNA to make crops stronger and produce more crop
Ex: tomato plants with arctic flounder DNA to withstand winter temperatures
Ex: plants with Bt toxin DNA in their genome to protect them from insects
– food
– animals

36. Genetically Modified Crops
Made plants more tolerable to our environment
Resistance to weeds
Added Bt toxin DNA in their genome to protect them from insects
Increase nutritional value to some plants
Ex: adding vitamin A to rice in Asia
– food
– animals

37. Genetically Modified Animals
Animals eat GM foods or are modified themselves to increase muscle mass or production
Ex: cows are injected with hormones to produced larger amount of milk, salmon injected to make larger muscles to eat

38. Vaccines
Substance containing all or part of a harmless strain of a pathogen
This gets introduced to our body and we build an immunity for it creating a defense system against the pathogen called antibodies
DNA vaccine: vaccine containing genes from pathogen but will not cause infection
Vaccines

39. DNA Fingerprinting 98% of our DNA does not code for a protein
Each person has a specific number of non-coding regions
Called VNTR (Variable Number Tandem Repeats)

40. DNA Identification
Used to identify criminals in a crime scene or to see family relation
Four steps to use DNA identification
1. Isolate DNA (make copies if small sample)
2. Cut DNA in fragments that are known VNTR areas
3. Sort DNA by size (using technology)
4. Compare size fragments to known samples

41. Gel Electrophoresis
Technology that separates DNA fragments by size in a gel to compare to known samples
Smaller DNA segments travel farther and faster down the gel

42. Gel Electrophoresis How to run a gel:
1. DNA sample gets cut up into short sequences
2. Each DNA sample (now cut up) gets added into its own chamber well

43. Gel Electrophoresis
3. Electric current is run through the gel for a specific amount of time
DNA is negatively charged and end of gel is positively charged
When current runs, the DNA fragments move towards the end of the gel

44. Gel Electrophoresis
4. DNA is transferred to a nylon membrane where probes are added and an X-ray is taken of the gel for copies to be made
Called a “bio fingerprint”

45. Gel Electrophoresis How to read results: