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3 years ago

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Biology

1 answer:

Lesechka [4]3 years ago

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Answer:Our planet's atmosphere has changed quite a bit over time. See the explanation below.

Explanation:

The planet is generally thought of as having three distinct atmospheres over the course of its lifetime.

When earth was first formed, its atmosphere was likely composed of hydrogen, helium, and other gases that contained hydrogen. Yet this atmosphere didn't last for very long because the solar wind from the sun blew it away. Solar wind is stream of charged particles such as electrons, protons, and alpha particles. We now have a magnetic field surrounding earth that shields us from solar wind.

The second atmosphere formed a little after 4.5 million years ago (mya) and was produced due to volcanic outgassing. Outgassing is the release of gas that was trapped in some other material. In this case, volcanic outgassing released hot gases trapped deep within the interior of the planet. Water vapor, carbon dioxide, methane, ammonia, and other gases similar to the ones produced by volcanoes today were expelled.

<h2>Over a vast amount of time, millions of years, the earth gradually cooled. When the temperature dropped enough, water vapor condensed and went from a gas to liquid form. This created clouds. From these clouds, the oceans formed and the oceans absorbed a lot of the carbon dioxide in the atmosphere. A small amount of oxygen was produced by the photolysis of carbon dioxide and water vapor by ultraviolet radiation. </h2>

Explanation:Our planet's atmosphere has changed quite a bit over time. See the explanation below.

Explanation:

The planet is generally thought of as having three distinct atmospheres over the course of its lifetime.

Lastly, we have the third atmosphere. Around 2.5 mya, the amount of oxygen available in the atmosphere started to rise due to the evolution of photosynthetic organisms that produced oxygen. These organisms were oceanic cyanobacteria. Over time, aerobic organisms evolved and consumed some of the oxygen produced. Read more about how oxygen became a major part of our atmosphere here.

This is the composition of the atmosphere we have today:

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The oak tree pathogen Phytophthora ramorum migrated 650 km in ten years. West Nile virus spread from New York to 46 others state

miv72 [106K]

Answer:

B) the mobility of their hosts

Explanation:

A pathogen that attacks an oak trees and a pathogen that attacks humans doesn't really have that big of a difference, but on the other side we can see that the pathogen that attacks the oak trees is spreading out much less and over much smaller territory than the pathogen attacking humans. The main reason behind this is the mobility of the host of the pathogen and where the host of it lives. In the case with the oak trees, the pathogen will be migrating very slowly over smaller distance because there's only certain places where the oak trees live, and also they are not mobile, and the pathogen will be able to spread out only through their seeds and cones which is a slow process. On the other hand, the pathogen attacking humans will manage to spread out very quickly over very large area because there are humans living in lot of places, their numbers are high, and their mobility is easy and quick over large distances, so the pathogen will travel with its host easily for hundreds or thousands of kilometers and then spread out in another place far away.

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The water travles up ;-/

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A usable dilution of disinfectant is one that prevents growth of bacteria when compared with the positive control tube. reduces

dolphi86 [110]

When compared to the positive control, a disinfectant dilution is considered to be useful if it stops bacterial growth.

Choosing a disinfectant:

When selecting a disinfectant, keep the following things in mind:

The range of bacteria that need to be eliminated. Look into the specifications of the manufacturers.

The conditions of usage of disinfectant.

Application of disinfectants :

Activity: it is necessary for efficient disinfection since, once diluted, it degrades over time. Different disinfectants deteriorate at different rates. Obtain data from the manufacturers. Disinfectants that don't have a color indication, like Virkon, should be marked with an expiration date.

Touch time: it has to be verified that the manufacturer's data to make sure the organism stays in contact for the specified amount of time. Considering that solid materials like cells and tissue granules are difficult for disinfectants to penetrate, autoclaving would be a more effective way to inactivate.

Therefore the correct choice is an option (A).

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