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frutty [35]
3 years ago
10

Which is the first era of Earth’s history?

Biology
2 answers:
sergiy2304 [10]3 years ago
7 0
I believe it’s Precambrian.
Igoryamba3 years ago
7 0

Answer:

Paleozoic era

Explanation:

The first major extinction in Earth's history occurred two to five million years ago, two deadly climaxes over hundreds of thousands of years. Most creatures lived in the seas at this time, so many of the marine creatures of that time, such as trilobites, brachiopods, and graptolites, were destroyed. During this third deadliest extinction, 5 to 5 percent of all species have been extinct.

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A sample of well water is tested for its bacterial content in a plate count assay. A one-milliliter sample of the water is dilut
Sholpan [36]

Answer:

The original water sample contains 830,000 cells per milliliter.

Explanation:

A sample of well water is tested for its bacterial content in a plate count assay. A one-milliliter sample of the water is diluted in a 1:10 dilution series. One milliliter of the fourth dilution tube is plated in a pour plate. After incubation, the plate has 83 colonies, indicating that the original water sample contained 830,000 cells per milliliter.

6 0
3 years ago
O<br>e<br>65°what is meant by the term photosynthesis ​
FrozenT [24]

Photosynthesis can be defined as the process by which green plants manufacture their food. Photosynthesis is important not only to plants themselves but also to animals, which depend on plants for food.

6 0
4 years ago
The coat of the t2 virus consists of what kind of macromolecules? see section 15.1 ( page 318) . the coat of the t2 virus consis
Karolina [17]
<span>The correct answer is protein.</span>  
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4 0
4 years ago
_________is severe pain and constriction about the heart, usually radiating to the left shoulder and down the left arm and creat
White raven [17]

Answer:

Heart attack

Explanation:

Heart attack is the death of a part of heart muscles and severe pain that causes heart constriction having pain in the chest which spread to the left shoulder and down the arm thereby causing the feeling of pressure in the chest.

This is caused when a blood clots blocks blood flow to the heart thereby leading makes the tissue to loss oxygen and die.

The symptom of heart attack are;

pain in the chest, neck, back or arms, fatigue, lightheadedness, abnormal heartbeat and anxiety, nausea.

Treatment ranges from surgery, medication , rehabilitation e.t.c.

7 0
3 years ago
Which phase in the cell cycle consists of the cell readying itself for its division?
notka56 [123]
The answer to your question is A
3 0
3 years ago
Read 2 more answers
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