biology

• Deoxyribonucleic Acid (DNA)


  A long molecule that contains our unique genetic code. Like a recipe book, it holds the instructions for making all the proteins in our bodies
• Biotechnology

  Includes a wide range of processes, from gene cloning to culinary processes and techniques that make use of living organisms to create products. It can also be helpful in environmental remediation and food production
• Recombinant DNA

  Cutting or cleavage of DNA by restriction enzymes, selection of an appropriate vector, ligation of the gene of interest with the vector, transfer of the recombinant plasmid into a host cell, selection process to screen cells containing the gene of interest, and sequencing of the gene to find out the primary structure of the protein
• Gene cloning is a part of biotechnology but is not limited to this technique. It also includes culinary processes, gene therapy, environmental remediation, and food production
• Genome


  An organism's complete set of genetic instructions. Each genome contains all of the information needed to build that organism and allow it to grow and develop. Our genome is approximately 3,000,000,000 base pairs long and is packaged into 23 pairs of chromosomes
• Ways to introduce plasmids into host organisms


  Not specified
• Genetic Engineering


  The artificial manipulation, modification, and recombination of DNA or other nucleic acid molecules in order to modify an organism or population of organisms
• Recombinant DNA Technology


  The joining together of DNA molecules from different organisms and inserting it into a host organism to produce new genetic combinations that are of value to science, medicine, agriculture, and industry
• Biotechnology is synonymous with gene cloning and is associated with the creation of the first cloned mammal, Dolly
• Recombinant


  A chromosome, cell, organism, etc., the genetic makeup of which results from recombination
• Genetic Engineering


  Classical breeding practices focus on the mating of organisms with desirable qualities. Genetic engineering involves the use of molecular techniques to modify the traits of a target organism, which may involve the introduction of new traits, enhancement of present traits, and disruption of the inhibition of desired genes' expression
• Methods to screen recombinant cells

  Selection of plasmid DNA containing cells, selection of transformed cells with the desired gene, PCR detection of plasmid DNA, genetically modified organisms (GMOs)
• Biolistics


  Short for "biological ballistics" and also known as particle-mediated gene transfer. It is the method of directly shooting DNA fragments into cells using a device called a gene gun
• ELECTROPORATION


  This technique follows a similar methodology as heat shock treatment, but the expansion of the membrane pores is done through an electric shock. This method is commonly used for insertion of genes into mammalian cells
• PLASMID INSERTION BY HEAT SHOCK TREATMENT

  Heat Shock Treatment is a process used to transfer plasmid DNA into bacteria. The target cells are pre-treated before the procedure to increase the pore sizes of their plasma membranes. This pre-treatment (usually with CaCl2) is said to make the cells “competent” for accepting the plasmid DNA. After the cells are made competent, they are incubated with the desired plasmid at about 4°C for about 30min. The plasmids concentrate near the cells during this time. Afterwards, a “Heat Shock” is done on the plasmid-cell solution by incubating it at 42°C for 1 minute then back to 4°C for 2 minutes. The rapid rise and drop of temperature is believed to increase and decrease the pore sizes in the membrane. The plasmids DNA near the membrane surface are taken into the cells by this process. The cells that took up the plasmids acquire new traits and are said to be “transformed”
• BIOLISTICS


  Short for “biological ballistics” and also known as particle-mediated gene transfer, is the method of directly shooting DNA fragments into cells using a device called a GENE GUN. To use a gene gun, a scientist first mixes a DNA construct with particles of a heavy metal, usually tungsten or gold
• GENE GUN


  Is used to fire DNA-coated pellets on plant tissues. Cells that survive the bombardment, and are able to take up the expression plasmid coated pellets and acquire the ability to express the designed protein
• SELECTION OF PLASMID DNA CONTAINING CELLS

  A selection marker within the inserted plasmid DNA sequence allows the selection of “transformants”. Usually, an antibiotic resistance gene (e.g. AMP ampicillin resistance gene) is included in the plasmid DNA. This allows only “transformed” cells to survive in the presence of the antibiotic (e.g. ampicillin). Plating the plasmid-cell solution on antibiotic-containing media will select for these “transformants” and only allow plasmid-containing cells to grow and propagate into colonies
• APPLICANTION OF RECOMBINANT DNA TECHNOLOGY

  Recombinant DNA technology is a popular genetic engineering process of cutting and recombining DNA fragments. DNA that contains genes for a particular protein are used and then recombined with the circular bacterial DNA (plasmid) and then inserted into a bacterial cell through a process called transformation. If scientists can alter DNA, they can then insert desired genes into another organism. They can modify the genes of bacteria to cause them to produce more desired yield
• SELECTION OF TRASNFORMED CELLS WITH THE DESIRED GENE

  Certain inserted genes within the plasmids provide visible proof of their presence. These include the antibiotic resistance genes that allow for the selection of the transformed cells within the solution. Some inserted genes also produce colored (e.g. chromogenic proteins) or fluorescent products (e.g. GFP) that label the colonies/cells with the inserted gene
• PCR DETECTION OF PLASMID DNA

  Alternatively, the presence of the desired gene in the inserted plasmids may be confirmed using PCR amplification. PCR reactions specific for the desired gene may be done using DNA from cells. Amplification of the expected product would confirm the presence of the gene within the samples. PCR reactions specific for plasmid sequences will also confirm/identify the type of plasmid used for the transformation
• Genetically Modified Organisms (GMOs)

  • Flavr-Savr Tomato
  • Bt-Corn
• The Flavr-Savr Tomato was the first genetically modified organism licensed for human consumption
• PCR amplification

  1. Reactions specific for the desired gene may be done using DNA from cells

  2. Amplification of the expected product would confirm the presence of the gene within the samples

  3. PCR reactions specific for plasmid sequences will also confirm/identify the type of plasmid used for the transformation
• Flavr-Savr Tomato


  • The ripening process is modified by disrupting the expression of a gene for an enzyme that softens the fruit, extending its storage and transport time
• With the ability to insert gene sequences, comes the possibility of providing new traits for target organisms, leading to the development of GMOs
• Bt-Corn incorporates the production of a toxin from Bacillus thuringensis, which is selective for pests like corn borer larvae and non-toxic to humans, mammals, fish, and birds
• Carbon-14 is a radioactive isotope of carbon used in radiocarbon dating due to its half-life of 5730 years
• Fossils are evidences of organisms that lived in the past, including actual remains and traces of past activities
• Categories of Fossil Types

  • Trace Fossils
  • Molds & Casts
  • Replacement
  • Petrified or Permineralized
  • Amber
  • Original Material
• Ways of Fossilization

  • Unaltered Preservation
  • Permineralization/Petrification
  • Replacement
  • Carbonization/Coalification
  • Recrystallization
  • Authigenic Preservation
• RECRYSTALIZATION

  Hard parts are converted to more stable minerals or small crystals turn into larger crystals
• CARBONIZATION / COALIFICATION


  The other elements are removed and only the carbon remained
• AUTHIGENIC PRESERVATION


  Molds and casts are formed after most of the organism have been destroyed or dissolved
• LAW OF SUPERPOSITION


  If a layer of rock is undisturbed, the fossils found on upper layers are younger than those found in lower layers of rocks
• However, because the Earth is active, rocks move and may disturb the layer making this process not highly accurate
• GEOLOGIC TIME SCALE is a record of the geologic history of the Earth, divided based on the appearance or disappearance of life forms
• Knowing the age of a fossil can help a scientist establish its position in the geologic time scale and find its relationship with the other fossils
• There are two ways to measure the age of a fossil: relative dating and absolute dating
• RELATIVE DATING

  1. Based upon the study of layer of rocks

  2. Does not tell the exact age: only compare fossils as older or younger, depends on their position in rock layer

  3. Fossils in the uppermost rock layer/strata are younger while those in the lowermost deposition are oldest