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neonofarm [45]
2 years ago
15

2. How has scientific understanding about the composition of the universe changed over time? Select the two correct answers.

Biology
1 answer:
mart [117]2 years ago
6 0

Answer: The percentage of unknown material has grown in scientists estimates since the 1970’s; the percentage of dark matter has shrunk in scientists estimates since the 1980s

Explanation:

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Atmospheric carbon dioxide dissolves into ocen surface waters
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Answer:

Carbon dioxide, which is naturally in the atmosphere, dissolves into seawater. Water and carbon dioxide combine to form carbonic acid (H2CO3), a weak acid that breaks (or “dissociates”) into hydrogen ions (H+) and bicarbonate ions (HCO3-).

Explanation:

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"What are the bacteria living in the ocean that do the nitrogen fixation, and were the first photosynthesizers on Earth providin
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Cyanobacteria

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Cyanobacteria were the first photosynthetic autotrophs that used water molecules as the source of electrons. Cyanobacteria were the first autotrophs that performed oxygenic photosynthesis and carried out the splitting of water.  

The process of splitting water released oxygen as a gas (O2) which was released in the atmosphere of the earth as a by-product. This led to the accumulation of oxygen in the atmosphere. Some cyanobacteria can fix nitrogen and have specialized cells called heterocyst which serve as the site for nitrogen fixation.  

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3 years ago
Expand difference between animal cell and plant cell​
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8 0
3 years ago
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vichka [17]

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When you make a fist after extending your arm and then flex your fingers, what statement is true?

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8 0
2 years ago
What tissue makes up a bone?
Mashutka [201]

Answer:

Bone tissue is a mineralized tissue of two types, cortical bone and callousness bone

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Other types of tissue found in bones include bone marrow, endometrium, peritoneum, nerves, blood vessels and cartilage.

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