Search results for: 'sulfur-labeled viruses'

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By: HWC, Views: 3806

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. ...

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Bacteriophage (Virus) - Mice Experiment

By: HWC, Views: 6380

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...

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HIV Infection: Viral life cycle

By: HWC, Views: 6013

The series of steps that HIV follows to multiply in the body. The process begins when HIV encounters a CD4 cell. The seven steps in the HIV life cycle are: 1) binding; 2) fusion; 3) reverse transcription; 4) integration; 5) replication; 6) assembly; and 7) budding. Many viruses f...

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Types of disease resistance: innate defenses & immunity

By: HWC, Views: 6849

Our immune system protects us and helps fight off disease. Microorganisms, small microscopic organisms, and viruses are everywhere. Ever thought about how many are on that door you just opened? Many microbes and viruses can cause disease and are termed pathogens. Plants and animals have what i...

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DNA Sequences - Dideoxy Sequencing

By: HWC, Views: 5966

A short, radiolabeled primer is annealed to the single-stranded DNA to be sequenced. The DNA serves as a template for in vitro DNA synthesis. The DNA-primer mixture is split into four separate tubes. DNA polymerase and a solution of dNTPs are added to each tube. One of the four 2',3' dideoxy-N...

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Random alignment at Metaphase I Animation

By: HWC, Views: 316

Possible outcomes of random alignment at metaphase I. In this example, three types of chromosomes are labeled 1, 2, and 3. Maternal chromosomes are dark blue; paternal ones are light blue. Suppose that at metaphase I all the maternal chromosomes became attached to one spindle pole and all the ...

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Cytotoxic T cell receptors, activation, proliferation, differentiation & action

By: HWC, Views: 6989

• Most cells which have CD8 on their surface become cytotoxic T cells (Tc cells). • CD8 T cells recognize a foreign antigen when it is presented in conjunction with the protein, MHC-I. • Nearly all nucleated cells in the body express MHC-I molecules. • T cells that recognize self-pe...

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How antibiotics works? 💊

By: HWC, Views: 6329

The Crisis in Antibiotic Resistance More than 70 years ago, Alexander Fleming discovered penicillin. A few decades later, when this antibiotic was used in World War II, Fleming's discovery had revolutionized medicine. No longer did people have to die from something as trivial as an infected cut.Y...

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B cells and antibodies

By: HWC, Views: 7466

What Are Antibodies? Antibodies, also known as immunoglobulins, are Y-shaped proteins that are produced by the immune system to help stop intruders from harming the body. When an intruder enters the body, the immune system springs into action. These invaders, which are called antigens, can be vi...

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