The correct answer is cyanobacteria (ancient cyanobacteria).
The huge concentration of oxygen in the atmosphere is believed to have been initially produced by the actions of ancient cyanobacteria. They are usually observed as symbionts with a number of another group of species, like coral, lichens (fungi), Azolla (pteridophytes), angiosperms, and others.
The atmosphere of oxygen was generated by various cyanobacteria at the time of Proterozoic and Archaean periods.
Answer:E. Down-regulation
Explanation:Cells typically up or down regulate depending on the concentration of a hormone levels. When there is a excessive concentration of a hormone in the blood stream, the cell decreases the number of receptors reducing the interaction with that hormone, Also, when there is excessive hormone reduction, the target cells activate to increase their number of receptors.
Down regulation occurs by the the deactivating or degrading of target cells to reduce the number of receptors due to their sensitivity to a particular excess hormone.
Answer:
wag umasa sa brainly
Explanation:
because ang utot mo ay mabaho
Answer:
A:T;G:C
Explanation:
adenine goes with thymine unless it's mRNA and it will go with uracil. guanine and cytosine always go together.
Hello!
While they do not penetrate very far into the body, they can indeed get through.
Commonly, materials that emit alpha, beta or gamma radiation get into the body alone or with other materials which have may become contaminated.
Here are some ways these could get in:
Through breathing; It could be in the air or mixed with dust, which is in the air.
Drinking; It disolves in water, meaning the material could get in your body without you knowing.
In the soil; If soil is contaminated, and plants grow in that soil, you will get a small ammount of alpha and beta particles.
Lastly, animals; Plants and animals can become contaminated, the particles coud be taken in through consumtion.
Hope this helps!
Have a great day!
