This is the restriction enzyme and acts as “molecular scissors” cuts the two DNA chains at a specific area in the genome so that sections of DNA can be supplemented or detached. A piece of RNA known as guide RNA is the second key molecule. This consists of pre-designed RNA quite small in length sequence, consisting of about 20 bases, positioned within a longer RNA scaffold. The scaffold binds to DNA and the pre-designed sequence ‘guides’ Cas9 to the right part of the genome. ensuring that the Cas9 enzyme intersects at the right point in the genome.
It contains genes, passed on from our parents, which construct our distinct features, e.g. Eye Colour, Hair Colour, Skin Colour etc. DNA must replicate in order to pass on the Genomes, the way this replication occurs is one DNA strand must act like a template and then it is copied to create a new strand which is an exact copy of the template. Protein is created by the information stored inside each gene’s DNA. The information is transferred to a molecule called Ribonucleic Acid (RNA).
Each strand serves as a template for the attachment of complementary bases. Then another molecule called DNA polymerase makes a new strand, using the code that matches each of the strands of the split DNA molecule and “proof-reads” each new DNA strand so that each new molecule is a perfect copy of the original DNA. When DNA makes a code it changes the sequence of the nitrogen bases into an RNA sequence. The only difference between DNA and RNA bases is that RNA has no thymine but instead has uracil. You would read the sequence three bases at a time.
Enzymes called topoisomerases produce breaks in the DNA molecules and then reconnect the strands, relieving strain and effectively preventing tangling and knotting during replication. DNA polymerase adds new nucleotides to a growing strand of DNA. Because DNA polymerase must adhere to an existing template, an RNA primer is first created at the site of replication. The RNA primer is synthesized by primase, an enzyme that is able to start a new strand of RNA opposite a DNA strand. After a few nucleotides have been added, the primase is displaced by DNA polymerase, which can then add subunits to the 3’ end of the short RNA primer.
Transgenesis and Cloning Transgenesis is the process of inserting a gene from one source into a living organism that would not normally contain the inserted gene. The gene can come from the same species (called Cisgenesis) or from a different species entirely. To facilitate the transfer of genes from one organism to another, often a Transgenic Organism with Recombinant DNA is created: -The first step in creating an organism capable of carrying out the transformation process is to isolate the required gene. This is done so using Restriction Enzymes, which target a specific gene sequence. The gene is often cut with staggered ends, called “Sticky Ends” which only allow specific and complementary gene sequences bond by base pairing.
Aurora kinases are involved in this checkpoint function. These kinases are only expressed during mitosis and overexpressed in a wide range of tumours. Aurora A is thought to play a role in regulating centrosome function. At the spindle checkpoint, Aurora B plays an essential role in recruiting proteins such as baba1 to the kinetechores. This promotes chromosome alignemtne, and ensures each daughter cell receives the correct number of chromosomes, The eukaryotic cell cycle is divided into several phases - G1, S, G2 and M. Chromosomal DNA replication takes place during S phase, whereas cell division (mitosis and cytokinesis) occurs
This complementary base pairing is what makes DNA a suitable molecule for carrying our genetic information—one strand of DNA can act as a template to direct the synthesis of a complementary strand. In this way, the information in a DNA sequence is readily copied and passed on to the next generation of cells. Because of the strict order of the chemical pairing, the double helix design facilitates the correct bonding of the appropriate chemical bases. However, some scientists suggest that the double helix design may also help to increase the physical strength of the gene. Gene construction is anti-parallel, meaning the strands run in opposite directions.
Synthesis, processing, and functionThe brief existence of an mRNA molecule begins with transcription and ultimately ends in degradation. During its life, an mRNA molecule may also be processed, edited, and transported prior to translation. Eukaryotic mRNA molecules often require extensive processing and transport, while prokaryotic molecules do not.  TranscriptionMain article: Transcription (genetics) Transcription is when DNA makes RNA. During transcription, RNA polymerase makes a copy of a gene from the DNA to mRNA as needed.
Plasmid has at least one DNA sequence that can act as an origin of replication. Plasmid almost always carry one or more gene which is responsible for a useful characteristic displayed by bacteria .e.g. Antibiotic resistance gene, therefore it is used as selectable marker. All plasmid possess atleast one DNA sequence that can act as an “origin of replication”, so they are able to multiply with the cell quite independently of the main bacterial chromosome. The smaller plasmids make use of the host cell’s own DNA replicative enzymes in order to make copies of themselves, whereas some of the larger ones carry genes that code for special enzymes that are specific for plasmid replication.
Study Guide: Mitosis and Meiosis prepared by Kathleen Bartholomew Mitosis is the process of dividing the replicated chromosomes of a single cell into two identical daughter cells. It is a part of cell division and happens during division of somatic cells. Mitosis is a form of asexual reproduction. It begins with a diploid cell, and ends with two diploid daughter cells. The number of chromosomes does not change in mitosis.