Used to define and identify geological times.<span />
This illustrates <span>absolute threshold. The correct option among all the options that are given in the question is the second option or option "B".
</span><span>A spot in the middle of the retina that only contains cones is called the fovea. The correct option among all the options that are given in the question is the third option or option "C".</span>
The fly species Drosophila santomea is found only on a single small island. Thus, this fly is considered to be "Endemic".
Answer:
In Branchiostoma, it is used mainly for feeding. The pharynx consists of numerous pharyngeal bars, with pharyngeal slits between them. The animal sucks in water through its mouth and forces it out through the pharyngeal slits, capturing small food particles from the water
