Well... a "build up in blood vessels" is actually called a CLOT. That should help you. :)
Freshwater does not contain any salt, salt water does however contain salt.
Answer: nucleus
Explanation: The nucleus contains the DNA which is a genetic material that contains all the instructions for protein synthesis. Before proteins are produced, the DNA is first of all copied into an single stranded RNA in a process known as transcription. This process takes place in the nucleus. The single stranded RNA then leaves the nucleus to the ribosome where protein synthesis takes place, there the RNA is translated into a polypeptide chain.
Answer:
Zooplankton - Animals (mostly microscopic) which drift freely in the water column.
Explanation: Zooplankton, small floating or weakly swimming organisms that drift with water currents and, with phytoplankton, make up the planktonic food supply upon which almost all oceanic organisms are ultimately dependent.
Hope this helped!!