If a microscope has a 40´ objective lens in place and a 15´ ocular lens, the total magnification of the microscope system under these conditions is

600`

Explanation:

The total magnification of a microscope is obtained by multiplying the magnifying power of the ocular lens and that of the objective lens.

Mathematically.

Total magnification = ocular magnification x objective magnification

In this case, ocular magnification = 40`, objective magnification = 15`

Total magnification of the microscope system = 40 x 15

                 = 600`

Hence,  the microscope system under these conditions would be 600`.

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.