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Hierarchical Sequencing Method - Sequence Tagged Sites

By: HWC, Views: 6979

In the hierarchical sequencing method, researchers begin by collecting cells. In humans, each cell contains 23 pairs of chromo-somes. Here we specifically track the DNA from just one of the 23 pairs. Chromosomes have a series of unique DNA sequences, called sequence-tagged sites (STSs), that a...

SNP Polymorphysim Microarray Chip - How to Test a Person's DNA

By: HWC, Views: 7045

To test a person's DNA, a researcher first needs a source of tissue. Most of the cells in a blood sample are red blood cells, which lack nuclei, but there are also a number of white blood cells, which do contain nuclei and chromosomal DNA. If we could see a particular DNA sequence in these cel...

ribosome

By: HWC, Views: 7478

The trp operon in E. coli contains five structural genes corresponding to enzymes that convert chorismate into tryptophan. The trpE gene contains a 5' untranslated region that plays an important role in the regulatory mechanism called attenuation. The 5' UTR contains four regions. Region 1 en...

Bacteriophage (Virus) - Mice Experiment

By: HWC, Views: 7458

Also known as phages, these viruses can be found everywhere bacteria exist including, in the soil, deep within the earth's crust, inside plants and animals, and even in the oceans. Bacteriophages (phages) are viruses of bacteria that can kill and lyse the bacteria they infect. ... The lethalit...

Hydrogen bonds vs. Ionic bond

By: HWC, Views: 6522

The slight positive charge of a hydrogen atom in a water molecule can attract an atom with a slight negative charge, such as the nitrogen in a molecule of ammonia. This forms a hydrogen bond between the two atoms. Hydrogen bonds join the two strands of a DNA molecule. Although hydrogen bo...

Double Stranded DNA Molecule Animation

By: HWC, Views: 5573

Double Stranded DNA Molecule Animation

Sister chromatids of a metaphase chromosome animation

By: HWC, Views: 5780

At metaphase, the chromosomes are duplicated and are at their most condensed. In each chromosome. two identical sister chromatids are held together at a constricted region called the centromere. When a chromosome is condensed, interactions among chromosomal proteins keep loops of DNA tightly ...

Hershey Chase Experiments

By: HWC, Views: 4901

Hershey and Chase knew that T4 bacteriophages consist of proteins and DNA. They asked which viral component must enter a bacterial cell to infect it: DNA or protein? They grew viruses with either radioactive sulfur, which labels the viral protein, or radioactive phosphorus, which labels DNA. ...

Transferring genes into plants Animation

By: HWC, Views: 5097

Researchers extract DNA from an organism that has a trait they want to introduce into a plant. The genetic donor can be a bacterial cell, a plant cell. or even an animal cell. The desired gene will be transferred into a plasmid, a small circle of bacterial DNA. The gene is cut out of th...