教育学习   常速英语

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JOHN SHEA: Those are nice principles. But let me give you a demonstration of this. Imagine if you will, that this is a depositive sediment. So this little ant farm-like deposit is an a...

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In eukaryotes, DNA transcription begins when general transcription factors bind to the promoter region of the gene. Those transcription factors facilitate the binding of the RNA polymerase enzyme to t...

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So shown here are three of some of my favorite viruses, I picked them for no apparent reason other than they look really cool. I've scaled them all to about the same size for easy viewing and despite ...

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Mosquitoes transmit many diseases among humans, including malaria, dengue, West Nile fever, and Zika. To keep mosquitoes from spreading disease, we must first understand their life cycle. The life cyc...

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This is a 3D model of a DNA molecule. It is made up of two strands that form a double helix. If we unwind the helix, we can see that each strand is a chain of building blocks called nucleotides. Le...

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Dengue virus is an RNA virus. Its outer surface is covered with envelope proteins surrounding a lipid bilayer envelope. Inside the envelope is a capsid shell that contains the virus’s RNA genome. Immu...

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Alright so now we're going to go into a little bit more detail on Dengue virus since it's once the subjects of our talk today. If you rotate it very carefully, I'm going to highlight for you the penta...

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Like all young mammals, human infants depend on milk for nutrition. Milk is rich in lactose, a disaccharide made from two sugar molecules. Lactose cannot be directly absorbed in the small intestine. T...