Edward Jenner inferred that a person who once had small pox cannot have it once again. So something is there in these persons which grows after the initial infection which interferes with the secondary infection resisting it.
<h3><u>
Explanation:</u></h3>
Edward Jenner is called the Father of Vaccination. Jenner noticed that the milkmaids who deal with the cows all the time don't generally suffer from the cowpox or small pox. Then as an Experiment, he took some sample from the pustules of the cow having pox and then cleaned it and injected the sample into a healthy child. Then when everyone of the locality suffered from the same disease, that child remained healthy. So that lead to infer that there are something in the pustule which lead to resist the secondary infection of this disease. So this lead to the invention of vaccines.
Paper, pencils, spoons, trash cans, etc
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.
The Term is called Niche Full distance of physical and
biological setting in which an organism lives and the way in which the
organisms uses those conditions. Causing species to divide resources,
competition helps determine the number and kinds of species in a community and
the niche eacthcies occupies.
<span> </span>
