Sponges are similar to other animals in that they are multicellular, heterotrophic, lack cell walls and produce sperm cells. Unlike other animals, they lack true tissues and organs, and have no body symmetry.
The shapes of their bodies are adapted for maximal efficiency of water
flow through the central cavity, where it deposits nutrients, and leaves
through a hole called the osculum. Many sponges have internal skeletons of spongin and/or spicules of calcium carbonate or silicon dioxide. All sponges are sessile
aquatic animals. Although there are freshwater species, the great
majority are marine (salt water) species, ranging from tidal zones to
depths exceeding 8,800 m (5.5 mi).
The reason why it is much easier to read while shaking your
head rather than reading and shaking the page is because of the vestibular
ocular reflex, it is because when reading and shaking your head the vestibular
ocular reflex were able to respond faster than prolong and slow movements.
The study of the lives of early human communities through the examination of their physical remains. Objects made by humans that are unearthed by archaeologists. ... The study of the earth, especially it's rock forms.
There are two hydrogen atoms in a molecule of water.
Answer:
atomic number or atomic mass
