The option which is true for urochordates is the second one - the notochord is present only in the larval stage; it is absent in adults.
B, Chromosomes
This is because the Z refers to the chromatin in the nucleus, aka the chromosomes.
Rubbing your hands together is an example of mechanical energy.
Mechanical energy is an objects sim of kinetic and potential energy when used to do work.
Hope this helps!
An acid rain is a type of rain or precipitation that has a high level of hydrogen ions resulting in low pH. It can prevent growth of seedlings because it hinders the cell division of plants. Since animals consume plants, they can establish new dietary habits or migrate to areas that have a healthier environment.