Unfortunately this question is incomplete as no options are provided. IN actual fact,<span> four muscles are involved in mastication. Three of these are responsible for biting down, namely the masseter, the temporalis and the medial pterygoid, whereas one, the lateral pterygoid, is responsible for opening of the jaw</span><span>. All four muscles help to move the jaw laterally.</span>
<span>There are two major theories that will explain on research on colour vision. They are 1. the trichromatic theory also known as the Young-Helmholtz theory 2. opponent-process theory. These two theories explain processes that operate at different levels of the visual system.</span>
Answer:
The structure of their noses.
Explanation:
Catarrhines are distinguished from platyrrhines by several traits but the main distinctive feature between them, is the structure of their noses. This forms the basis of their names.
Platyrrhines are characterized by laterally-placed, rounded nostrils or flat-nosed while catarrhines have narrow, downward-facing nostrils or hooked-nosed.
Another distinguishing feature include their dental formulation which is 2.1.2.3 in catarrhines and 2.1.3.3 in platyrrhines.
The skull structure of catarrhines have frontal bone which make contact with the sphenoid bone unlike the platyrrhines.
Generally, catarrhines are much bigger in size than platyrrhines.
For the first question the answer is C the second one the answer is A