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Arlecino [84]
3 years ago
15

Which describes oxygen content as Earth evolved over time? Oxygen levels sharply declined about 400 million years ago. Oxygen le

vels stay above 15 percent starting 200 million years ago Oxygen levels remain below 5 percent starting 1000 million years ago. Oxygen levels raise significantly between 1000 and 700 million years ago.
Biology
1 answer:
denis-greek [22]3 years ago
7 0

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".

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Duplication in the gene encoding a protein invalided in vision has enabled human to acquire trichromatic vision which type of mu
Doss [256]

Answer:

beneficial mutation

Explanation:

A mutation is any alteration in the genetic material of an organism. In general, mutations have a negative impact on the fitness (or reproductive success) of the individual that carries this mutation; however, there are situations where a mutation may be beneficial for the individual in a given environment. When a beneficial mutation occurs in the germline, it potentially can be passed to the next generation and progressively increases its frequency in the population.

6 0
2 years ago
Help me, please with this :)
WARRIOR [948]

Answer:

Please find the answer to the blank spaces in each statement of the attached image in CAPS.

1. All energy comes from the SUN

2. Plants, algae and some bacteria capture energy by PHOTOSYNTHESIS in their CHLOROPLAST.

3. Plants, animals, fungi, protists, and most bacteria release energy by RESPIRATION in their MITOCHONDRIA.

Note:

- Photosynthesis requires CARBON DIOXIDE (CO2) and WATER (H20) to make GLUCOSE (C6H12O6) and OXYGEN (02)

- Respiration requires GLUCOSE (C6H12O6) and OXYGEN (02) to make CARBON DIOXIDE (CO2) and WATER

Explanation:

The image in this diagram is depicting how energy flows from the ultimate source, which is the SUN to other living organisms. Plants, algae and some bacteria have the ability to capture energy from the SUN using pigments in their CHLOROPLAST in a process called PHOTOSYNTHESIS, which they use to synthesize their food. The process of photosynthesis requires CARBON DIOXIDE (CO2) and WATER (H20) to make GLUCOSE (C6H12O6) and OXYGEN (02) gas.

However, on the contrary, virtually all living organisms including: Plants, animals, fungi, protists, and most bacteria etc. release energy via an organelle called MITOCHONDRIA in a process called RESPIRATION. The process of respiration requires GLUCOSE (C6H12O6) and OXYGEN (02) to make CARBON DIOXIDE (CO2) and WATER.

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2 years ago
An allele whose trait always shows up in the organism is called
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An allele whose trait always shows up in the organism is called the answer is dominant allele.
7 0
3 years ago
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A client has an above-the-knee amputation of the left leg because of arterial insufficiency. to prevent a hip flexion contractur
frez [133]
The nurse should position the client at a prone position every 3 to 4 hours for 20 to 30 minutes periods. This should be done periodically. Arterial insufficiency is any condition that slows or stops the flow of blood through your arteries. Arteries are blood vessels that circulate blood from the heart to other parts of the body.
3 0
3 years ago
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Which statement about membranes is TRUE? Most plasma membranes contain more than 70% proteins sterol lipids are common in human
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Answer:

Sterol lipids are common in human cell plasma membranes

Explanation:

Human plasma cell membrane contains sterol lipids and proteins which serves as structural maintainers of the cell.

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