There is no pigment in the brain, so it is in it's natural colour, grey.
Actually, it is INNATE IMMUNITY. That is the proven right answer so be careful.
Answer:A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. ... Unlike sea anemones, corals secrete hard carbonate exoskeletons that support and protect the coral.
Coastal oceans are commonly defined as the areas from the shoreline to the outer edge of the continental margin. They connect the continents to the open ocean and serve as a link for transporting organic and inorganic, natural and anthropogenic material from land to sea.
Coastal oceans in tropical areas have similar characteristics to their temperate counterparts. ... Coral reefs are biologically diverse and rich habitats that occur in relatively nutrient-poor environments along coastlines. Areas that have too many nutrients often harbor too much algal growth to sustain coral growth.,
Answer:
yes
Explanation:
as the atrium contracts , blood flows from your right atrium into your right ventricle through the open tricuspid valve. when the ventricle is full, the tricuspid valve shust . this prevents blood from flowing backward into the right atrium while the ventricle contracts
