The mantle i think sorry if i am wrong
A. Your leg jumping when it is hit by a reflex hammer
Sunspots are temporary phenomena on the Sun's photosphere that appear as spots darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic field flux that inhibit convection. Sunspots usually appear in pairs of opposite magnetic polarity.
I believe option B would be the correct choice because, without a catalyst, the reaction will be either too slow or will not happen at all as it would not acquire a fitting activation energy for the reaction.
If you would like to know why the other options are incorrect, please read on:
Option A is incorrect because since proteins are specific in nature, so other protein cannot be replaced, for some other chemical reaction.
Option C is not correct it is a genetic defect that the protein does not form, and all cells are genetically identical, a reaction cannot take place in any parts of the body.
And finally, option D would be wrong because if a forward reaction does not take place, a backwards reaction will not occur.
I hope this answer has helped, and I apologise if somehow this answer finds itself to be incorrect. Good luck on your quiz or homework. :)
Answer:
The calcium concentration must be greater OUTSIDE
the cell than INSIDE the cell.
Explanation:
Calcium has a vital role in the body, it is necessary for:
- exocytosis
- muscle contraction
- normal excitability of neurons
- blood coagulation
- building and maintaining bones and teeth
- enzymatic activity