Answer:
Chitin.
Explanation:
The structure that is not a component of wall of sponges is Chitin. Their body comprise of calcareous or siliceous spicules or protein spongin fibres. Choanocytes are the distinctive cells located in the interior body walls of sponges. Sponges are similar to other animals in many characteristics such as they are multicellular, heterotrophic, lack cell walls and produce sperm cells in order to produce offspring sexually and also different from animals due to lack of tissues and organs.
Answer:
Some political scientists need a background in marine science so they can understand marine life and can make policies in an attempt to regulate human behavior to protect the ocean and ocean life. Marine scientists must be able to understand the diverse life in the ocean
Explanation:
BRAINLIESTTTT PLZ
When an ecosystem has a scarce nutrient, that is when there is a nutrient limitation.
So the answer is C. <span>Nitrogen is typically the limiting nutrient in freshwater environments.
This is because Nitrogen is the "scarce" nutrient </span>
