Earth's history. In the worst one, 250 million years ago, 96 percent of marine species and 70 percent of land species died off. It took millions of years to recover.
Answer:
The monomers of DNA are individual nucleotides: cytosine, guanine, adenine, and thiamine, (A, T, C, G, respectively). Since DNA is a double-stranded molecule, each nucleotide has a match that chemically interacts with it to form nucleotide pairs
Explanation:
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The virus life cycle could be divided into six steps: attachment, penetration, uncoating, gene expression and replication, assembly, and release.
These are some ways how scientists and engineers develop, use and refine models.
1. Imagine. They have to know what exactly trying to model. They have to imagine and brainstorm what are the things to be considered.
2. Reason. Next, they need to answer the questions brought from their brainstorming. They need to be able to reason out.
3. Calculate and Predict. Once they know it, that's the time they can start modelling and calculate - and predict.
