Pls where do most metamorphic processes take place? a. at least a hundred kilometers below earth’s surface, in the mantle b. in the first few kilometers below earth’s surface c. at least a few kilometers below earth’s surface, in the lithosphere and upper mantle d. in the mantle and upper core

A. at least a hundred kilometers below Earth’s surface, in the mantle

Explanation:

Metamorphic rocks are rocks which are formed from existing rocks. They change their form which results in their formation. Examples include marble,Schist etc.

They are formed under conditions such as temperature greater than 150 to 200 °C and pressure of 1,000 bar and above thereby causing intense physical or chemical change.

Their formation occurs at least a hundred kilometers below Earth’s surface, in the mantle .

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation: