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kipiarov [429]
4 years ago
13

What is the predominant hypothesis why animals only appeared in the fossil record about 3 billion years after life originated?

Biology
1 answer:
Amiraneli [1.4K]4 years ago
3 0
A. There were animals 3 billion years ago; they just weren't fossilized. B. Animals are warm-blooded; the ocean was too cold for animals.
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I WILL MARK YOU AS THE BRAIN THINGY PLEASEEE HELP
Rufina [12.5K]

<u>Pressure increases with depth </u>

Explanation:

Pressure increases with depth because the molecules at the deeper end are compressed by the weight of the above column of the fluid. Compression means there are more molecules of the fluid per volume in the deepest place than the surface. More molecules mean more pressure.

This is why divers need special gear when diving deep in the ocean to protect themselves form increased water pressure. In addition, the lowest atmospheric layers have the highest pressure because they are more dense and bear the weight of the above air column. This is why air pressure is a bit lower up the summit of a mountain than at its base.

5 0
4 years ago
Which of the following is an example of a prokaryote?
alekssr [168]

Answer:

C. Bacteria

Explanation:

An example is E. coli. In general, prokaryotic cells are those that do not have a membrane-bound nucleus.

6 0
3 years ago
Read 2 more answers
Identify the true statements regarding liver glycogen phosphorylase a. Protein phosphatase 1 is abbreviated PP1. The binding of
katrin2010 [14]

Answer:

Liver phosphorylase a concentration decreases when glucose enters the blood.

The binding of glucose to liver phosphorylase a shifts the equilibrium from the active form

As the concentration of phosphorylase a decreases, the activity of glycogen synthase increases. to the inactive form

Explanation:

Protein phosphatase 1 (PP1) is a phosphatase enzyme known to remove phosphate groups from serine/threonine amino acid residues. PP1 plays diverse biological roles including, among others, cell progression, control of glucose metabolism, muscle contraction, etc. In glucose metabolism, PP1 regulates diverse glycogen metabolizing enzymes (e.g., glycogen synthase, glycogen phosphorylase, etc). In the liver, glycogen phosphorylase catalyzes the rate-limiting step in glycogenolysis by releasing glucose-1-phosphate. Glycogen phosphorylase <em>a</em> is converted (and inactivated) into the <em>b</em> form by PP1, which catalyzes the hydrolysis of the phosphate bond between serine and the phosphoryl group. In the liver, glucose binds in order to inhibit glycogen phosphorylase <em>a</em>, thereby inducing the dissociation and activation of PP1 from glycogen phosphorylase <em>a</em>.  

5 0
3 years ago
Tetrodotoxin (ttx) is a neurotoxin that blocks voltage-gated na+ channels. what will happen in an organism that ingests ttx? all
Alborosie
This question is unfortunately incomplete. A <span>neurotoxin that blocks voltage-gated na+ channels will have all of the effects listed: there will be impairment of action potentials and neurotransmitter release, and in sufficient quantities, the toxin will prove fatal to the organism.</span>
3 0
3 years ago
Which statement is true of succession? Most communities are already completely stable. Most communities take hundreds of years t
Setler79 [48]

Answer:

Option B, Most communities never become completely stable

Explanation:

In an ecological succession, most of the species are unstable and they keep on changing continuously. The succession is primarily of two types –  

a) Primary Succession – In this, community of species occur on a new habitat which had been never occupied earlier. Or it can be said that it is entirely a new habitat.

b) Secondary Succession – In this, community of species occur in a habitat where earlier life existed but it was disturbed or damaged by some environmental condition.  

Hence , the correct answer is option B

4 0
3 years ago
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