Definition: A radioactive isotope of sulfur.
Statement: Alfred Hershey and Martha Chase constructed an experiment to determine if DNA is the genetic material of cells by using radioactive sulfur (35S) to label the protein component of T2 phages. This allowed the scientist to observe if the sulfur would enter an infected bacterium.
Definition: A radioactive isotope of phosphate.
Statement: Due to phosphate being a natural component of DNA, Alfred Hershey and Martha Chases infected T2 phages with 32P. Thus, the DNA became radioactively labeled in the T2 phages. As a result, the radioactive phosphate allowed the scientist to observe if the DNA of the T2 phages entered an infected bacterium.
3) annealing (in terms of DNA)
Definition: The process of joining two complementary single strands of DNA or RNA to a double stranded molecule.
Statement: During DNA replication, the hydrogen bonds are broken to form two single stranded molecules. Once the DNA stranded has been replicated, the single strands are annealed back to the original form.
4) antiparallel (in terms of DNA)
Definition: The direction in which DNA molecules are organized.
Statement: The strands of DNA molecules run antiparallel to each other. This allows for the nucleotides on one strand to pair to the nucleotides on the other strand. The 5-prime end of one strand of DNA will match the 3-prime end of the other strand. As a result, the DNA strands are aligned in opposite directions
5) central dogma
Definition: The process by which the sequences of nucleotides in a DNA molecule forms a protein.
Statement: The central dogma provides steps of how a DNA molecule forms an RNA molecule which leaves the nucleus to form a protein. The proteins that are produce from this process are used by living organisms to maintain homeostasis.
6) complementary (in terms of DNA)
Definition: The matching of base pairs that are organized in the strands of nucleic acids. For instances; guanine pairs with cytosine and adenine pairs with thymine in a DNA molecule.
Statement: The double helix structure of DNA includes two complementary strands where the nitrogenous base on one strand matches the nitrogenous base on another strand.
7) conservative replication (in terms of DNA)
Definition: A hypothesized process of DNA replication that results in the original DNA molecule and new strands of DNA. This occurs when the original DNA strands are replicated, and those strands are joined.
Statement: It is hypothesized the DNA replication occurs by conservative replication where the daughter strands include the original DNA strands and new strands a DNA.
8) denaturation (in terms of DNA)
Definition: The separations of the two strands of DNA. This process results in two single stranded DNA molecules. Denaturation occurs during DNA replication.
Statement: The first step in a polymerase chain reaction (PCR) cycle is denaturation of the DNA segment to allow enzymes to anneal the DNA strand and extend the strands countless times to produce numerous copies of DNA
Definition: The genetic material located in the nucleus of cells that provides a sequence of nucleotides for protein formation. DNA carries that genetic information that determine the growth of living organisms.
Statement: The genetic information of a living organism is incorporated in the DNA of the cells to provide the instructions for the organelles of the cell to function. DNA carries the information that gives organisms their traits.
10) DNA fingerprinting
Definition: The procedure used to identify an individual based on their unique genetic makeup. Due to DNA being unique to every individual, DNA can be analyzed to determine the differences and similarities between individuals.
Statement: Forensics is able to use DNA fingerprinting to determine the identity of criminals and place individuals at the scene of the crime.
11) DNA polymerase
Definition: An enzyme used in the processes of DNA replication. DNA polymerase synthesizes complementary DNA strands from the original DNA strands.
Statement: During DNA replication, the two strands separate to allow DNA polymerase to create a new strand of nucleotides from the original strand of DNA.
12) DNA profiling
Definition: Analyzing the unique genetic makeup of a living organism to determine identification or to identify genetic diseases.
Statement: All individuals should create their own DNA profile to determine if they have acquired any genetic diseases from their parents.
Definition: An enzyme used during DNA replication for the degrading of nucleotides and their bonds.
Statement: When a white blood cell acquires foreign DNA in an individual, DNase is used to hydrolyze the unwanted DNA.
14) dominance or dominant
Definition: A trait that is expressed over another trait. When an individual carries a heterozygous gene, the dominant allele will be the observed trait.
Statement: When an offspring acquires a heterozygous gene from their parent, only the dominant allele will be represented in the observable trait.
Definition: Refers to DNA being double stranded. DNA has two strands that are complimentary of one another.
Statement: Genetic information is contained in dsDNA and holds the instructions for all living organisms.
Definition: An enzyme that breaks the phosphodiester linkages or the bonds of nucleic acids.
Statement: An endonuclease must be used during DNA replication in order to separate the strands and allow the an original strand to be replicated.
Definition: An allele that is hidden by a dominate allele. Do not affect the individual in a heterozygous gene. The dominant allele will mask the effects of a recessive allele.
Statement: An individual suffering from cystic fibrosis will only reveal the symptoms if they contain homozygous recessive alleles.
Definition: A defining characteristic of an individual. Can be observed traits that are the result of alleles.
Statement: Genes are passed on from parent to offspring and they carry the information needed to produce the organism’s traits.
Definition: Alternative versions of a single gene.
Statement: Alleles determine the defining traits of a living organism.
Definition: The physical location of a gene on a chromosome.
Statement: The gene that codes for the protein that gives an individual blue eyes can be located on the locus of their chromosomes.
Definition: Structures located in the nucleus of the cell that contain the genetic information of a living organism.
Statement: The nucleus of a cell carries chromosomes that provides the instructions for an organism’s defining characteristics.
Definition: The observed trait of an individual.
Statement: During Mendel’s experiments with the pea plant, he recorded the phenotypes of the F1 generation to determine the receiving traits the plants acquired from the parents.
Definition: An enzyme that discards of the nucleotides located on a DNA strand. The enzyme begins removing nucleotides at the ends of the chains.
Statement: An exonuclease cleaves nitrogenous bases by starting at one end of the DNA strand and working towards the other end. These enzymes can remove any nucleotides that form genes that code for harmful proteins. They can only cleave one at a time.
Definition: A specific sequence of nucleotides on a strand of DNA that influences the result of an organism’s traits. Can be transferred from parent to offspring by sexual reproduction.
Statement: Similar genes can be passed on from parent to offspring and code for similar observable traits.
25) gene family
Definition: A collection of similar genes that encode identical proteins or RNA strands. The proteins that are produced from these genes have similar structures and functions.
Statement: Offspring may receive a collection of gene families from their parents. These genes can cause the offspring to have similar traits to their parents.
Definition: The entire collection of nucleotide sequences that make up the genetic information of an organism. This hereditary information can be passed on from parent to offspring. Additionally, the genetical material is in the cells of an organism.
Statement: An organism contains a genome that results in the formation of all of their traits.
27) in vitro
Definition: A process or experiment that occurs outside a living organism. These experiments can take place in a petri dish or a test tube.
Statement: In a university microbiology lab, students will collect samples of bacteria in vitro over the course of the semester.
28) in vivo
Definition: An experiment that occurs in a living organism.
Statement: The creation of new drugs for individuals must be tested with an in vivo experiment to determine the effectiveness of the drug.
29) melting temperature
Definition: The specific temperature point where double stranded DNA molecules separate. This occurs during DNA replication.
Statement: The denaturation step in a PCR cycle occurs when the DNA reaches a melting temperature.
30) negative super coiling
Definition: A process of twisting double stranded DNA molecules in the opposite direction of supercoiling. Negative supercoiling prepares that section of the DNA molecule for separation.
Statement: When a DNA molecule rotates counterclockwise to separate the strands, negative super-coiling has occurred.
31) positive super coiling
Definition: The process of twisting a DNA molecule in the same direction as the strands. The direction is clockwise. The strand overwinds to cause fewer base pairs per turn.
Statement: When DNA strands undergo positive super coiling, there are fewer base pairs per each turn. The DNA twisted in the same direction of the two strands.
Definition: A molecule that consists of a sugar group and a nitrogenous base.
Statement: Nucleosides are the central components and found within DNA molecules and are the building blocks of nucleotides.
Definition: The molecule in DNA and RNA that includes the sugar, nitrogenous base, and the phosphate group.
Statement: DNA and RNA are formed by a sequence of nucleotides that code for a specific protein.
34) Avery, Macleod and McCarty
Definition: Published work that declared DNA as the hereditary information of bacteria. The experiment undertook a purification process. It was determined that DNA was an active component in bacterium.
Statement: Following Frederick Griffith’s experiment with the smooth virulent type of Pneumococci, Avery, Macleod, and McCarty conducted an experiment that confirmed DNA as the transforming principle in bacteria.
35) Frederick Griffith
Definition: Conducted experiments with different types of Pneumococci on mice to observe their effects. His effort led to the discovery of DNA as the genetic information in living organisms.
Statement: Frederick Griffith formulated the transforming principle by injecting mice with different types of Pneumococci. He observed the effects that the combined types of Pneumococci had on mice and concluded that bacteria was able to transform from one strain to the other.
36) transforming principle
Definition: Discovered by Frederick Griffith that states that bacterium can take up DNA from another cell and use it to incorporate changes.
Statement: Scientists have confirmed that the transforming principle that Fredrick Griffith postulated is the DNA of bacteria.
Definition: The acquiring of DNA in a bacterium from another cell and integrated into the recipient DNA.
Statement: In bacteria, transformation can occur in order to help the cell survive in harsher environments.
Definition: Occurs in eukaryotic cells when the cell acquired new genetic information and integrated it into its DNA.
Statement: Genetically engineered crops are modified by a process known as transfection. This process helps the crops survive from weeds and introduce more nutrients.
39) Hershey and Chase
Definition: Conducted an experiment on T2 phages and bacteria to confirm that DNA was the genetic material of bacteria and viruses. They used 32P to label the phosphate in the DNA of the T2 phages and 35S to label the sulfur to label the sulfur in the protein that make up the virus. This experiment showed the DNA of T2 phage located inside the bacterium.
Statement: Alfred Hershey and Martha Chases conducted a blender experiment that showed DNA as the transforming principle of bacteriophages.
40) Meselson and Stahl
Definition: Usage of a centrifuge to determine the mechanism by which DNA replicates. The DNA was altered with an isotope of nitrogen to affect the density of the molecule. A strand from original DNA molecule was discover in each newly formed DNA. The conclusion was that DNA replication is semi-conservative.
Statement: DNA was confirmed to replicate semi conservatively by the experiment conducted by Matthew Meselson and Franklin Stahl. Their experiment showed that each original strand was found in the newly replicated strands.
41) Thomas Hunt Morgan
Definition: Use experiments on fruit flies to establish the chromosomal theory of inheritance. Identified the locations of chromosomes and linked them to formation of hereditary traits.
Statement: Thomas Hunt Morgan confirmed chromosomes as the carriers of genes that make up the traits of an organism.
42) Friedrich Miescher
Definition: Conducted different experiments with the purpose of discovering DNA. From his experiment he was able to isolate nuclein. His work led to the discovering and identification of nucleic acids.
Statement: From the cells extracted from bandages of wounded soldiers, Friedrich Miescher was able to isolate nuclein from white blood cells.
Definition: A combination of DNA and proteins. It was first isolated by Friedrich Miescher.
Statement: Nuclein can be extracted from the nucleus of any cell from a living organism.
44) Walther Flemming
Definition: A cytogenetists that developed that first staining techniques that identified cell division. This staining technique also showed the threadlike structures in the nucleus of the cell. They were identified as the chromosomes with the chromatids separating during cell division.
Statement: Using salamander embryos, Walter Flemming was able to identify chromosomes with staining techniques.
45) Walter Sutton
Definition: Scientist that hypothesized that chromosomes contained genetic information in living organisms. He linked Mendelian laws to chromosomes.
Statement: Walter Sutton published worked that theorized that Mendelian laws of hereditary were linked to chromosomes.
46) semiconservative replication
Definition: A type of DNA replication that includes strands from the original DNA strands joined to the new DNA strands.
Statement: It was discovered that DNA replication occurs by semiconservative replication.
47) Erwin Chargaff
Definition: Theorized that the number of nitrogenous bases pairs contain an equal amount inside the genetic material of the cell. This theory help form idea that DNA was a double helix.
Statement: Erwin Chargaff developed the Chargaff rule that states adenine pairs with thymine and cytosine pairs with guanine. The rule also states that there is the same number of adenine molecule as there is thymine molecules. Same concept applies to guanin and cytosine.
48) Linus Pauling
Definition: Scientist that discovered the structure of a protein and led to the identification of the structure of DNA.
Statement: Linus Pauling develop the theory that DNA model a triple-stranded helix structure. The theory was proved incorrect, however, it helped aid the discovery of DNA shaped in a helix.
49) Watson and Crick
Definition: Scientists that identified the structure of DNA. They theorized the model of DNA being a double helix.
Statement: The discovery of the structure of DNA was made by Watson and Crick. They stated that the shape DNA is a double helix where the strands are antiparallel to one another. Both Watson and Crick received Nobel Prizes for their work on DNA.
50) Rosalind Franklin
Definition: Scientist who contributed to the identification of the structure of DNA by taking an X-ray diffraction image of DNA. This image showed the B-form structure of DNA appearing as a helix.
Statement: Rosalind Franklin, a chemist and X-ray crystallographer, aided in the discovery of the structure DNA, however, she did not receive credit at the time for her work.
51) Photo 51
Definition: The image that the X-ray crystallographer Rosalind Franklin took that identified the structure of DNA.
Statement: Photo 51 was an image of DNA that helped Watson and Crick develop the theory that DNA was shaped as a double helix.
Definition: A type of nitrogenous base where the structure has a double ring. This causes the molecule to have a higher melting point than a single ring base. Adenine and Guanine are both purines.
Statement: Adenine and Guanine are both consider purines due to their double-ringed shape.
Definition: A structure containing one carbon-nitrogen ring base. The type of nucleotides in a DNA molecule that are pyrimidines includes: Thymine and Cytosine. The nucleotide Uracil is another pyrimidine which is found in an RNA molecule. These molecules are single-ringed nitrogenous bases.
Statement: Pyrimidine has a lower melting point than purines due to the shape being single-ringed.
54) renaturation (in terms of DNA)
Definition: The process of reuniting denatured DNA strands. The DNA strands are single complementary strands.
Statement: After DNA strands have been denatured, enzymes can renature that strands to form its original structure.
55) restriction enzyme
Definition: An enzyme in bacteria or archaea that can recognize a specific DNA sequence. If the enzyme does not recognize the DNA sequence or detects foreign DNA, the enzyme can cut or break down that DNA sequence.
Statement: Bacteria can protect its DNA from viruses by using restriction enzymes to located and break down foreign DNA.
56) restriction fragment length polymorphism
Definition: A technique used to identify different lengths of restriction fragments made by restriction enzymes between two individuals. The fragments occur at targeted sites on a DNA sequence. Can be used for genetic analysis.
Statement: The genetic analysis of two individuals may show one individual with restriction fragment length polymorphism.
57) restriction map
Definition: A technique used to identify the target locations on a DNA sequences where restriction enzymes will cleave that specific DNA sequence.
Statement: Restriction mapping allows individual to observe the location where restriction enzymes will break down DNA in bacteria to add a new DNA sequence.
58) Drosophila melanogaster
Definition: Scientific name for the fruit fly which are used in many common experiments for their advantages such as fast life cycle and reproducing quickly.
Statement: The Drosophila melanogaster is more advantages to use in a genetic experiment than a plant due to the ability of the Drosophila melanogaster to reproduce faster.
59) Saccharomyces cerevisiae
Definition: The scientific name for common bakers’ yeast which is a model organism used in scientific experiments for their eukaryotic cell properties.
Statement: The process of transfection is eukaryotic cells was discovered by experimenting with Saccharomyces cerevisiae.