Prokaryotic cells don't have a nucleus
The control group is the part of an experiment that does not receive the variable and is used for comparison.
Answer:
c. Cr. N. IV = trochlear nerve
Explanation:
The IV cranial nerve is the trochlear nerve. It is located on the dorsal side of the brain near the back. It is a motor nerve and the smallest nerve which serves eye. This nerve present in the superior oblique muscle of the eye. The superior oblique muscle controls the rotational movement of the eyeball and prevent the eyeball from rolling upward into the eye socket.
The right option is; B) the total variety of organisms on Earth
The total variety of organisms on Earth explains biodiversity
Biodiversity is the variety and variability of all species (different plants, animals and microorganisms) from all sources (marine, terrestrial and other aquatic ecosystem) on earth or within a particular region. Biodiversity involves genetic diversity, species diversity and ecosystem diversity which all functions together to form the complexity of life on earth.