Lysogenic replication of bacteriophage viruses
By: Tami Port MS
Bacteriophages are a type of virus that prey upon bacterial cells. The reproduction of bacteriophages always involves death of the infected bacterium, when the viruses burst out or lyse their prokaryotic host cell. Bacteriophages reproduce by commandeering a bacterium and ultimately killing it. But sometimes...
Positive gram stain reaction of bacteria
By: Tami Port MS
Gram + bacteria stain purple due to the chemistry and structure of their peptidoglycan cell wall. Here's how Gram staining identifies Gram-positive organisms.* The Gram Stain *In the 1800's, Christian Gram, a Danish bacteriologist, developed a technique for staining bacteria that is still widely...
Negative gram stain reaction of bacteria
By: Tami Port MS
Gram- bacteria stain pink due to the location of cell wall peptidoglycan and an external LPS membrane. Here's how Gram staining identifies Gram negative organisms.* Christian Gram's Stain *In the 1800's, Christian Gram, a Danish bacteriologist, developed a technique for staining bacteria that is...
Lytic replication of bacteriophage viruses
By: Tami Port MS
Bacteriophages are a special type of virus that exclusively infects bacterial cells. Here's how they recognize, take over and ultimately kill their host bacteria.* Viral Host Recognition *Most viruses infect only a certain type of host. This specificity is due to the affinity of...
DNA selective signature of genes
By: Tami Port MS
Genetic sequencing allows MIT scientists to examine natural selection through the selective signature of a gene across a range of microbial species. This new method of analysis identifies the selective signature of genes, the pattern of differences in genetic sequences that indicates the rate of...
Gram stain reaction of bacteria
By: Tami Port MS
Gram staining involves the application of a series of dyes that leaves some bacteria purple (Gram +) and others pink (Gram -). Here's how the Gram stain works.* From Spontaneous Generation to Germ Theory *Through most of recorded history, illnesses that we now recognize...
Pharaoh Ants
By: Diane Garrod
Meet the Pharoah ant (Monomorium pharaonis (L.). Two words describe it, annoying and troublemaker. They are tiny and hard to destroy. They breed continuously, nest in secluded areas and eat sweets and fats. Its name is thought to be derived as being one of...
Hereditary versus somatic DNA mutations
By: Tami Port MS
There are two main categories of mutation based on the type of cell that the genetic change occurs in. These alterations to a person's DNA can be inherited or acquired after fertilization. Here is a summary of the difference between hereditary and somatic DNA mutations...
What is mitochondrial DNA (mtDNA)?
By: Tami Port MS
Mitochondria are the cellular organelles that manufacture most of the energy that our cells need to function. Cellular respiration, series of reactions that take place within the mitochondria, complete the process of turning food energy into ATP energy that can be used in many different...
Everything you need to know about Crazy Rasberry Ants
By: Gillian Taber
Crazy Rasberry Ants, also known as Rasberry Crazy Ants, are a new species of exotic ant. They were found in Houston, Texas in 2002. They are known to spread rapidly and are considered invasive. The ant falls into the Paratrechina family but has yet to...

 

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