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3 years ago

8

Before there was any life on earth, which gas was absent from earth’s ancient atmosphere? A. nitrogen B. ammonia C. oxygen D. me

thane

1 answer:

maksim [4K]3 years ago

7 0

Easy. Answer is oxygen because it says which one was missing before any life was on earth. And in order to have life on earth you need oxygen!
:)

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4. Which pathway represents the flow of electrons during photosynthesis? (1 point) A.) H2O > Photosystem I > Photosystem I

Yuki888 [10]

Answer:

4. The correct pathway for the flow of electron during photosynthesis is mentioned in option D. $H_{2}O$ > <em>NADP </em>> <em>Calvin cycle.</em>

Electron is first provided to the photo-system II by the phtolysis of water.
Then it is passed to photo-system I with the help of plastoquinone (PQ) and cytochrome $b_{6}f$ .
Finally, electron from the photo-system II is used to reduce NADP to NADPH.
NADPH and ATP are used in light independent phase or Calvin cycle to synthesize carbohydrate from carbon dioxide.

5. The correct answer is B.) photosynthesis.

Photosynthesis is the process by which green plants synthesize glucose or carbohydrate from carbon dioxide and water in presence of sunlight and chlorophyll.
In light independent phase of photosynthesis, it requires ATP and NADPH in order to synthesize food.
Lastly, oxidation or breaking down of glucose releases energy and photosynthesis is a anabolic process instead of catabolic one.

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3 years ago

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beks73 [17]

The substance is pure depending on which atoms bond.

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3 years ago

What happens in meiosis during telophase ii

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During telophase II, the fourth step of meiosis II, the chromosomes reach opposite poles, cytokinesis occurs, the two cells produced by meiosis I divide to form four haploid daughter cells, and nuclear envelopes (white in the diagram at right) form.

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2 years ago

Kenya starts to get into the hot tub, but the water feels extremely hot. she stands in the water for a few moments, then slowly

rewona [7]

The answer is 'sensory adaptation'. This happens when your sensory system senses a constant stimulus. After a short while, your sensory system will respond less, and then won't respond at all. This is to allow adaption to your environment. For example, if you live above a subway system, you will eventually become used to the sound of underground trains and vibration, and eventually you won't notice it at all..

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3 years ago

describe a region where you would expect to find mitotic division occurring in a plant, and also a mammal. URGENT DUE TOMORROW

Yuki888 [10]

Special cells, just behind the radicule, plumule or in buds. divide using mitosis

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3 years ago