Changing the DNA of an organism is called genetic engineering. The organism that results is called a genetically engineered organism. The use of this method is so widespread that it has been given its own category - recombinant DNA technology (a branch of molecular biology)

Genomic in-situ hybridization is the name of a useful tool. It is widely used to analyze plant structures to ascertain their origin, location and genomics.

Molecular evidence can prove or disprove some fylogenetic relations between organisms that were previously based on morphologic aspects or ecologic aspects.

X- linked traits can only be inherited through the x-chromosome, while other traits are inherited either by both the x and y chromosome or just the y-chromosome.

Source:

BSCS Biology: A Molecular Approach, Blue Version Ninth Edition

Salt water usually refers to a a solution of common salt, sodium chloride, NaCl.

There are four major organic molecules in the body, which are called macromolecules. These include lipids, carbohydrates, proteins and nucleic acids.

No, this molecule is not ionic. It is composed of all non metal atoms. In order to be ionic, the compound should consist of the following combinations: metal + nonmetal, or metal + polyatomic ion, or 2 polyatomic ions together.

CH3OH is molecular.

Yes they do.

DNA, proteins, carbohydrates, lipids, Vitamins, mineral salts are fundamental molecules of living system. DNA codes for information that can make RNA and proteins. Proteins act as enzymes and builds body. Carbohydates and lipids are mainly energy producers, lipids can also takes part in membrane, hormone productions. vitamins and minerals are vital for various cellular metabolic processes.

The "central dogma" states information goes from DNA to RNA to Protein in a retrovirus it goes from RNA to DNA back to RNA to Protein. The central dogma as it is called has so many exceptions now that it is no longer considered central.

algology, mycology, palaeobotany [Brit, Cdn], paleobotany [N. Amer], phycology, pomology, pteridology.

Water is a relatively unique molecule as the Oxygen atom shares electrons with both Hydrogen atoms, and also has two lone (unshared) pairs of electrons. This makes the physical structure of the molecule bent or v-shaped. This shape, with the Oxygen at the point of the vee, and the Hydrogens at the ends, makes the molecule polar. A polar molecule has a relative negative charge at one end, and a relative positive charge at the other. Becuase all ionic molecules (salt, NaCl) are also polar, and like dissolves like, water's polarity can 'grab onto' salt's polarity and pull it apart, dissolving it.

The chemical equation is:

H2O(l) + NaCl(s) --> H2O(l) + Na+(aq) + Cl-(aq)

Where l means liquid, s solid and aq aqueous (dissolved) Water is a relatively unique molecule as the Oxygen atom shares electrons with both Hydrogen atoms, and also has two lone (unshared) pairs of electrons. This makes the physical structure of the molecule bent or v-shaped. This shape, with the Oxygen at the point of the vee, and the Hydrogens at the ends, makes the molecule polar. A polar molecule has a relative negative charge at one end, and a relative positive charge at the other. Becuase all ionic molecules (salt, NaCl) are also polar, and like dissolves like, water's polarity can 'grab onto' salt's polarity and pull it apart, dissolving it.

The chemical equation is:

H2O(l) + NaCl(s) --> H2O(l) + Na+(aq) + Cl-(aq)

Where l means liquid, s solid and aq aqueous (dissolved)

Molecular because it is between 2 non-metals.

water molecules are polar (there is an unequal charge around the molecule) The oxygen end of the water molecule is negatively charged and the hydrogen ends of the water molecule is positively charged. thus, the oxygen will attract positive atoms and the hydrogens will attact negative atoms

The tRNA molecule functions to pick up specific amino acids to take to the ribosomes which contains the anticodon that base pairs with the codon of the mRNA strand. This controls the type of amino acid is attached to the protein being formed.

Discovered DNA, professor of Biology at Harvard , Nobel prize in 1962, wrote a book called THE DOUBLE HELIX , uncovered the molecular nature of cancer, ran the human genome project and identified 50,000 to 100,000 genes.

Identical twins are known as monozygotic twins in terms of medicine or genetics as they arise from the same egg and sperm cell. Although the same genome or DNA shared in to both embryo during development of fetus, epigenetic changes, surrounding, exposures, nutrition influence,imprinting mechanism make them different. This make the different gene expression pattern in identical twins. For a detailed review please read the following review paper(attaching the link).

Techniques of molecular biology Expression cloningOne of the most basic techniques of molecular biology to study protein function is expression cloning. In this technique, DNA coding for a protein of interest is cloned (using PCR and/or restriction enzymes) into a plasmid (known as an expression vector). This plasmid may have special promoter elements to drive production of the protein of interest, and may also have antibiotic resistance markers to help follow the plasmid. This plasmid can be inserted into either bacterial or animal cells. Introducing DNA into bacterial cells can be done by transformation (via uptake of naked DNA), conjugation (via cell-cell contact) or by transduction (via viral vector). Introducing DNA into eukaryotic cells, such as animal cells, by physical or chemical means is called transfection. Several different transfection techniques are available, such as calcium phosphate transfection,electroporation, microinjection and liposome transfection. DNA can also be introduced into eukaryotic cells using viruses or bacteria as carriers, the latter is sometimes called bactofection and in particular uses Agrobacterium tumefaciens. The plasmid may be integrated into the genome, resulting in a stable transfection, or may remain independent of the genome, called transient transfection. In either case, DNA coding for a protein of interest is now inside a cell, and the protein can now be expressed. A variety of systems, such as inducible promoters and specific cell-signaling factors, are available to help express the protein of interest at high levels. Large quantities of a protein can then be extracted from the bacterial or eukaryotic cell. The protein can be tested for enzymatic activity under a variety of situations, the protein may be crystallized so its tertiary structure can be studied, or, in the pharmaceutical industry, the activity of new drugs against the protein can be studied . Polymerase chain reaction (PCR) The polymerase chain reaction is an extremely versatile technique for copying DNA. In brief, PCR allows a single DNA sequence to be copied (millions of times), or altered in predetermined ways. For example, PCR can be used to introduce restriction enzyme sites, or to mutate (change) particular bases of DNA, the latter is a method referred to as "Quick change". PCR can also be used to determine whether a particular DNA fragment is found in a cDNA library. PCR has many variations, like reverse transcription PCR (RT-PCR) for amplification of RNA, and, more recently, real-time PCR (QPCR) which allow for quantitative measurement of DNA or RNA molecules. Gel electrophoresis Gel electrophoresis is one of the principal tools of molecular biology. The basic principle is that DNA, RNA, and proteins can all be separated by means of an electric field. In agarose gel electrophoresis, DNA and RNA can be separated on the basis of size by running the DNA through an agarose gel. Proteins can be separated on the basis of size by using an SDS-PAGE gel, or on the basis of size and their electric charge by using what is known as a 2D gel electrophoresis. Arrays A DNA array is a collection of spots attached to a solid support such as a microscope slide where each spot contains one or more single-stranded DNA oligonucleotide fragment. Arrays make it possible to put down a large quantity of very small (100 micrometre diameter) spots on a single slide. Each spot has a DNA fragment molecule that is complementary to a single DNA sequence (similar to Southern blotting). A variation of this technique allows the gene expression of an organism at a particular stage in development to be qualified (expression profiling). In this technique the RNA in a tissue is isolated and converted to labeled cDNA. This cDNA is then hybridized to the fragments on the array and visualization of the hybridization can be done. Since multiple arrays can be made with the exact same position of fragments they are particularly useful for comparing the gene expression of two different tissues, such as a healthy and cancerous tissue. Also, one can measure what genes are expressed and how that expression changes with time or with other factors. For instance, the common baker's yeast, Saccharomyces cerevisiae, contains about 7000 genes; with a microarray, one can measure qualitatively how each gene is expressed, and how that expression changes, for example, with a change in temperature. There are many different ways to fabricate microarrays; the most common are silicon chips, microscope slides with spots of ~ 100 micrometre diameter, custom arrays, and arrays with larger spots on porous membranes (macroarrays). There can be anywhere from 100 spots to more than 10,000 on a given array. Arrays can also be made with molecules other than DNA. For example, an antibody array can be used to determine what proteins or bacteria are present in a blood sample. Allele Specific Oligonucleotide Allele specific oligonucleotide (ASO) is a technique that allows detection of single base mutations without the need for PCR or gel electrophoresis. Short (20-25 nucleotides in length), labeled probes are exposed to the non-fragmented target DNA. Hybridization occurs with high specificity due to the short length of the probes and even a single base change will hinder hybridization. The target DNA is then washed and the labeled probes that didn't hybridize are removed. The target DNA is then analyzed for the presence of the probe via radioactivity or fluorescence. In this experiment, as in most molecular biology techniques, a control must be used to ensure successful experimentation. Abandoned technology As new procedures and technology become available, the older technology is rapidly abandoned. A good example is methods for determining the size of DNA molecules. Prior to gel electrophoresis (agarose or polyacrylamide) DNA was sized with rate sedimentation in sucrose gradients, a slow and labor intensive technology requiring expensive instrumentation; prior to sucrose gradients, viscometry was used. Aside from their historical interest, it is worth knowing about older technology as it may be useful to solve a particular problem.