Answer:
What can be noticed about the ligands and their receptor is that the configuration of both coincide, as a key would with its lock, which demonstrates the specificity of a receptor by its ligand.
Explanation:
A <u>ligand</u> corresponds to a molecule considered a signal or a messenger, while the <u>receptor</u> is a protein on the cell surface, with the capacity to accept a ligand.
Ligands and receptors constitute pairs that complement each other, so that <u>each receptor can bind to a specific ligand</u>, similar to what happens with a key and a lock.
Once the ligand-receptor complex is formed, changes occur inside the cell, which define a certain effect.
Soil erosion is defined as the wearing away of topsoil. Topsoil is the top layer of soil and is the most fertile because it contains the most organic, nutrient-rich materials. Therefore, this is the layer that farmers want to protect for growing their crops and ranchers want to protect for growing grasses for their cattle to graze on.
D. skeletal muscle and cardiac muscle