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3 years ago

Which best explains the inability for life to exist in Earth’s early atmosphere? Select two options.

Biology

2 answers:

topjm [15]3 years ago

6 0

Answer:

Bro we need to see the options.

Explanation:

Options please.

just olya [345]3 years ago

6 0

Answer:

Volcanic eruptions and comet collisions added different gases to the atmosphere.

Explanation:

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Derived from a 6 membered ring. Contains Cytosine, Thymine, and Uracil.

dybincka [34]

Answer:

b. Nucleotides

Explanation:

Nucleic acids are examples of structures formed from nucleotides. And in relation to the composition of DNA, we have the formation of the largest cellular macromolecule, all formed by nucleotides.

The nucleotide is a group formed by the association of 3 molecules - a nitrogen base, a phosphate group and a pentose glycide. Thus, we may have variations within these ligands, such as: in DNA we have the presence of pentose deoxyribose, while in RNA we have the presence of pentose ribose.

The nucleotides have differences in relation to its nitrogen base, which can be purine or pyrimidine. Purine bases vary in Adenine and Guanine, while pyrimidine bases are classified in Thymine, Uracil and Cytosine. Purine and pyrimidine bases are complementary and each have specific binders. Thus, we have that the purine base Adenina, binds with the pyrimidine bases Timina and Uracila, while the base Guanina binds exclusively to Cytosine and vice versa.

5 0

3 years ago

Pain signals often have two components: an acute sensation of "first pain" which is felt almost immediately after an injury, and

o-na [289]

Answer:

This suggests that neurons that send the signals that we perceive as first pain Myelinated Tpye A-delta___, and neurons that send the signals that we perceive as second pain Unmyelinated-Type C.___.

Explanation:

Physiologically, primary afferent neurons that innervated the the touch, pain, temperature,and pressure receptors in the effectors to input sensory signals to the spinal cord and the brain are categorized based on their diameter, sizes, and nature of myelination. Based on this;

A-alpha has the largest diameter, myelinated, and sensitive to sensation from the muscle cells

A-beta are next in diameter, myelinated and sensitive to sensation of touch.

A-delta followed in diameter, and size. They are mylinated, and sensitive to pain and temperature.

C-fibres are least in diameter, they are unmyelinated, but sensitive to pain, touch and temperature.

Therefore, if the speed of conduction,of action potential in a neuron depends on the diameter(thickness) and myelination of the axon(saltatory conduction) :

''then, acute sensation/ first pain should be transmitted by the A-delta fibre. While the the slower/second pain should be transmitted by the slower unmyelinated - C-fibres''.

5 0

3 years ago

How do scientist use layers of rock to determine when the Great Oxidation event occured?

Oksanka [162]

Answer:

Using the concept of relative dating

Explanation:

Scientists use the concept of relative dating principles to determine when the Great Oxidation event occurred.

Relative dating is the process of placing ancient event in their proper time sequence based on the relationship between rock lithologies.

An event like the great oxidation will have significant chemical, biological and physical effect on the rock units.
Rocks that form during this period in time will have very unique chemical signatures.
Therefore, by studying these rocks, the age of the layer can be fixed when we compare it to the standard geological column.

8 0

3 years ago

what is a difference between atp and adp molecules?a)adp can be used to directly power movement, while atp cannot. b)atp molecul

cestrela7 [59]

c)atp has three phosphate groups, while adp has two phosphate groups.

6 0

3 years ago

Classify each description as being a characteristic of microtubules, intermediate filaments, or actin filaments.

AlekseyPX

I found the exercise on the internet and attached are the descriptions.

Actin filaments:
-"play a role in cleavage furrow formation during cell division"
-"function in muscle contraction"

Microtubles:
-"make up the core of cilia and flagella"
-"are composed of tubulin subunits
-"maintain cell shape by resisting compression"

Intermediate filaments:
-"are not involved in cell motility"
-"fix certain organelles in place"

7 0

4 years ago

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