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tia_tia [17]
3 years ago
14

Based on fossil evidence, about how long ago did the first

Biology
2 answers:
bixtya [17]3 years ago
7 0

Answer:

The correct answer will be option-4.1 billion years ago.

Explanation:

Earth the only planet in the universe which harbors life was formed around 4.5 billion years ago.  

Organic molecules formed from the inorganic molecules started aggregating and formed the first single-celled organisms which were microscopic. The fossil evidence found in the deep rocks and hydrothermal vents in the ocean suggests that single-celled organisms were formed around 3.5-4.2 billion years ago.

Thus, option-4.1 billion years ago is the correct answer.

garik1379 [7]3 years ago
3 0
Around 4.1 billion years ago the first single celled organism appeared
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alekssr [168]
Well, dissolved carbon is basically carbon, and carbon and other atmospheric gases dissolve in water. So that would most likely lead to the answer being oceans and lakes.
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3 years ago
Astrocytes A. all of these B. induce the formation of the blood-brain barrier C. physically support neurons D. are important in
Keith_Richards [23]

Astrocytes perform the function of all of the given options i.e., induce the formation of the blood-brain barrier, physically support neurons, are important in the repair of brain injuries and in neural formation, take up excess K from the brain ECF.

  • Both invertebrates and vertebrates have Astrocytes, a star-shaped cell kind of neuroglia, in their nervous systems.
  • Astrocytes can be separated into protoplasmic and fibrous kinds. In the central nervous system's white matter, myelinated nerve fibers are frequently surrounded by fibrous astrocytes.
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b) The development of the blood-brain barrier is aided by the Astrocytes

c) Astrocytes support neurons physically and metabolically.

d) Astrocytes help in transfer of blood-borne materials to the neuron, and injury response of the brain and repair of brain injuries.

e) They also help with detoxification, migratory guidance, energy metabolism regulation and removal of excess K from brain ECF.

learn more about astrocytes here: brainly.com/question/6966928

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3 0
1 year ago
The main smoking related diseases and how they affect health
inna [77]

Answer:

Heart disease.

Heart attack

Stroke.

<h3><u> By damaging your airways and the small air sacs (alveoli) found in your lungs.</u></h3><h3><u /></h3><h2>Hope this helps! Have a nice life!</h2>
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2 years ago
What's the culture of Thyme?
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Explanation: Hope you have a bright and beautiful day!!!

4 0
2 years ago
What are the similarities and differences between plant, animal, and fungal cells?
nlexa [21]

Answer:

They are eukaryotic cells, they present the three main parts: cell or cytoplasmic membrane, cytoplasm and nucleus defined with chromosomes and nucleolus. The three types of cells have in common the following structures: cell membrane, cytoplasm, nucleus defined with chromosomes and nucleolus, mitochondria, smooth and rough endoplasmic reticulum, ribosomes, Golgi apparatus, cytoskeleton and peroxisomes. But it differs in some. The plant cell has chloroplasts and a cell wall and the animal cell does not.

Explanation:

The animal cell has centrioles, lysosomes. It has no plastids, no cell wall, it has vesicles. They do not have the ability to produce their own food from inorganic components. The plant cell has plastids (chloroplasts), cell walls, large vacuoles. Fungal cells are organisms without chlorophyll, therefore they cannot photosynthesize. The reserve substances of the cytoplasm are not starch granules. As they are not able to synthesize their food, they have to obtain from other living organisms (they feed on other plant and animal residues contributing to decomposition) that is, they are heterotrophic. Fungal cells have a cell wall that is not present in animal cells and but plant cells have a cell wall. They have lysosomes and centrioles that the plant cell lacks but they are in animal cells. Animal cells, with a few exceptions, do not have vacuoles while plant cells do. The three types of cells have present nucleus, membrane, mitochondria, endoplasmic reticulum, Golgi system.

4 0
2 years ago
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