D.
They break down dead organisms.
I’m pretty sure it’s hydrogen if I’m wrong I’m really sorry
When babies are born, their brains contain about a hundred billion of neurons. However, a few of these brain cells are connected. At age three, there are one thousand trillion connections formed. The brain starts to cut off unused connections at the age of eleven.
Flowering plants are the most successful land plants because theri seeds are protected in fruits
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