Flatworms (Platyhelminthes) are phylum of unsegmented, soft, flat invertebrates.
Flatworms have no body cavity which is why they are flat. The advantage of a flat body is facilitated respiration and circulation. Flatworms do not have respiration and circulation system. But, oxygen diffuses across the skin and reach all parts of the body thanks to a flattened shape. Also, it is easy to hide from predators because they can get almost everywhere thanks to the body shape.
p53 protein is involved in control of cell cycle, which explains it role in tumor/ cancer suppressor
D, hydrotrophism.
the word gives the answer away because Hydro is a word meaning water
The corpus callosum, a tight region of axons (whitematter), is the direct connection and thus communication between left and right hemispheres.
A "split-brain" could result from disruption of or damage to the corpus callosum, either in part or whole.
Atomic number of an atom equals to the number of nucleus in the nucleus of the atom. Therefore, the answer is 74.
The proton of an element is never changed. No matter if it's an atom or ion. It's like an ID number for an element. It defines the type of element. Don't mix up atomic number with mass number though, mass number is the total sum of of the number of protons and neutrons in an atom.
Theres one more subatomic particle in an atom, that is electrons. But since they're too light, they won't be counted in mass. Also, the number of electrons in an atom equals to the number of proton, also the atomic number. If the number of electrons is different, it's no longer an atom, but an ion.