Answer:
D. Cell wall
Explanation:
Cell wall is also present in prokaryotes it is made of peptidoglycan layer.
Answer:
They have a closed circulatory system.
Explanation:
In an open circulatory system, blood vessels transport all fluids into a cavity. When the animal moves, the blood inside the cavity moves freely around the body in all directions.
Closed circulatory systems are different to open circulatory systems because blood never leaves the blood vessels. Instead, it is transferred from one blood vessel to another continuously without entering a cavity.
Answer:
Because of their food.
Explanation:
Phosphorus can be found in foods (organic phosphorus) and is naturally found in protein-rich foods such as meats, poultry, fish, nuts, beans and dairy products.
Answer:
It is a quantitative observations
C. were conditioned to salivate in response to the sound of a bell.
