Answer :There was enough oxygen in the atmosphere to support a major burst of life on Earth
Explanation:
The Great Oxygen Event marks the time, approximately 2.5 billion years ago, when there was enough oxygen in the atmosphere to support a major burst of life on Earth
For the first half of the Earht's history, there was no oxygen in the atmosphere. It was inhabited only by single-celled organisms.Of those simple life forms, the cyanobacteria may have. evolved a way to take energy from sunlight, and used it to make sugars out of water and carbon dioxide. They used the same chemical process we know as photosynthesis. This released vast quantities of oxygen into the atmosphere and triggered the evolution of complex life.
Answer:
The principal components of the plasma membrane are lipids ( phospholipids and cholesterol), proteins, and carbohydrates.
The correct answer is D) The codon AUG must be identified.
What must occur for protein translation to begin is that the codon AUG must be identified.
The process starts when the 5AUG or start codon is identified. In the polypeptide chain, the 5AUG is the first amino acid. We are talking about Transition, the process when the genetic code in an RNA molecule has to be decoded in a polypeptide chain in order to deliver an amino acid sequence. In this complex transition system, there are important components included such as ribosomes, transfer RNA, and mRNA.
Answer:
It was an experiment to prove that DNA was made of genes. They discovered that protein was NOT genetic material.
Explanation:
"In their experiments, Hershey and Chase analyzed what happened when phages infect bacteria... They found that <em>when phages infect a host bacterium, the phages first attach themselves to the outside of the bacterium. Then, a piece of the phage enters the bacterium and subsequently replicates itself inside the cell. After many replications, the phage causes the bacterium to lyse, or burst, thereby killing the host bacteria.</em> Scientists classified the replicating piece as genetic material. Scientists also found that phages contained two classes of biological molecules: DNA and protein.
Hershey and Chase utilized a technique called radioactive isotope labeling. Chemical elements can exist in different structural forms called isotopes. Isotopes of the same element are nearly identical, but scientists can distinguish between them by experimental means. One way to differentiate between chemical elements with different isotopes is by analyzing their radiation. Some isotopes are less stable than others and give off radioactive signals that scientists can detect. Hershey and Chase marked phages by incorporating radioactive isotopes of phosphorus and sulfur in those phages. They allowed some phages to replicate by infecting bacteria, specifically Escherichia coli, or E. Coli, that scientists had grown in radioactive sulfur. The researchers let other phages infect and replicate in E. Coli that scientists had grown in radioactive phosphorus. DNA contains phosphorus, but not sulfur, whereas protein contains sulfur, but not phosphorus. Therefore, when Hershey and Chase marked phages with radioactive isotopes of those elements, they placed separate, distinguishable tags on the protein and DNA parts of the phages."
cited:
https://embryo.asu.edu/pages/hershey-chase-experiments-1952-alfred-hershey-and-martha-chase
