Answer:
The correct answer is - it obtains electrons from the oxygen atom in a water molecule, so it must have a stronger attraction for electrons than oxygen has
Explanation:
P680 known as which contains a reaction center in photosystem two, it is a very strong oxidizing agent that catalyzes the transfer of electrons from H2O to a bound quinone, with the production of O2.
To have a stronger attraction for electrons than oxygen has, P680 gets electrons from the O2 atom in a water molecule.
Answer:
Oxygen levels stay above 15 percent starting 200 million years ago
Explanation:
Atmospheric oxygen levels are related to the evolution on Earth and changes in geochemical cycles that involve climate variations.
The presence of O
2 and evolution of oxygen gave new opportunities to the life on Earth. Oxygen levels in atmosphere have fluctuated between 15% and 35% of atmospheric volume, since the start of the Cambrian period.
So, form the starting 200 million years ago, oxygen level stay above 15 percent and the correct option is "B".
Stored in the laboratories at the centers for disease control and prevention and a Russian laboratory in Siberia are the only two place in which Smallpox virus remains.
<h3>What is smallpox?</h3>
Variola major or Variola minor are the two virus strains that cause the contagious sickness known as smallpox. The variola virus (VARV) agent is a member of the genus Orthopoxvirus. The World Health Organization confirmed the illness's universal eradication in 1980 after the last naturally occurring case was diagnosed in October 1977, making polio the only human disease to have achieved this feat.
Fever and vomiting were among the disease's earliest signs. This was followed by the development of mouth ulcers and a rash. The skin rash developed into the typical fluid-filled blisters with a dimple in the middle over a period of days. The scars were left after the lumps scabbed over and dropped off. People could contract the illness from contaminated things or from one another. Prevention is through the vaccine for smallpox.
To learn more about smallpox with the help of given link:
brainly.com/question/13167254
#SPJ4
<span>For each count, only one digit changes.</span>
Answer:
A. Progressively increase over a period to time
Explanation: