|
|
Genetic Variation
Sexual Reproduction results in variation of organisms among a species. This is a great benefit, for all of the organisms are slightly different, with varying strengths and weaknesses.
All gametes produced from ONE organism, such as a human males, are slightly different. This is due to the action of crossing over that occurs during meiosis. See the illustration below. Crossing over is where two homologous chromosomes exchange genetic information. Each of the 4 chromosome are separated and placed into four different gametes (sex cells).
It is because of crossing over that two parents can have four daughters that all look a little different from each other.
All gametes produced from ONE organism, such as a human males, are slightly different. This is due to the action of crossing over that occurs during meiosis. See the illustration below. Crossing over is where two homologous chromosomes exchange genetic information. Each of the 4 chromosome are separated and placed into four different gametes (sex cells).
It is because of crossing over that two parents can have four daughters that all look a little different from each other.
Karyotypes:
A karyotype is a chart that shows all of the chromosomes in a single cell. This chart is useful in determining the gender of an individual, and any chromosomal abnormalities, such as trisomy or monosomy.
The Central Dogma of Biology
DNA is the major polymer found in every cell; this molecule is essential for the cell to produce proteins. DNA will be transcribed in the nucleus into messenger RNA. mRNA will leave the nucleus and travel to the ribosome (ribosomal RNA), where transfer RNA (tRNA) is able to translate the message into a sequence of amino acids. tRNA reads the mRNA 3 bases at a time, a codon, and uses the following chart to bring certain and specific amino acids to the ribosome.
Genetic Technology
Polymerase Chain Reaction:
In order to make many copies of DNA, a polymerase chain reaction will be conducted. PCR is like the man-made process of DNA replication. After 30 rounds of the process, there are over a billion copies of DNA
In order to make many copies of DNA, a polymerase chain reaction will be conducted. PCR is like the man-made process of DNA replication. After 30 rounds of the process, there are over a billion copies of DNA
Gel Electrophoresis is amongst the most important method used to compare DNA and proteins. It is often used to compare mother, father, and child's DNA. It is also very commonly used to compare a suspect's DNA to the DNA found at a crime scene.
The premise is that the DNA is cut into fragments, by restriction enzymes. These fragments travel down a gel by an electric current. Short fragments move faster and farther than larger fragments. Two exact copies of DNA will have the same exact 'banding pattern' in the gel.
The premise is that the DNA is cut into fragments, by restriction enzymes. These fragments travel down a gel by an electric current. Short fragments move faster and farther than larger fragments. Two exact copies of DNA will have the same exact 'banding pattern' in the gel.
Cloning
Cloning is the process of producing an organism that is genetically identical to the organism which it was derived. Cloning is made possible by removing the nucleus from the organism you wish to clone, inserting it in an empty cell (without a nucleus), and inserting that now complete cell into a 'surrogate' mother to grow into an embryp.
Genetic Engineering
Genetic engineering allows scientists to artifically make genes. This method if often used to make a protein that an individual is missing.
For example, diabetics need to take insulin. Insulin is a protein. Where does this protein from from? Scientists took the segment of DNA that codes for the insulin protein. They insert it into a bacterial cell, because bacteria can replicate by mitosis quickly. After several rounds of replication, there are many copies of the gene that codes for insulin. We now have insulin to give to diabetic patients who need it.
For example, diabetics need to take insulin. Insulin is a protein. Where does this protein from from? Scientists took the segment of DNA that codes for the insulin protein. They insert it into a bacterial cell, because bacteria can replicate by mitosis quickly. After several rounds of replication, there are many copies of the gene that codes for insulin. We now have insulin to give to diabetic patients who need it.