Answer:
Ligand-receptor interaction is the first interaction that triggers cell signalling.
Ligands are the hormones, drugs or neurotransmitters that specifically bind with receptors present in cell surface to initiate cell signalling. Ligand binding to the receptor is reversible. Binding of the ligand to the receptor can activate or inactivate receptor. Activation may lead to cell signalling pathways. Inside cells, there are secondary molecules which on activation starts a cascade of reactions. which in-turn regulate the function of the ligand molecule.
At first, the activated receptor relates with G proteins molecules in the cell.
before the ultimate physiological effect of the ligand on the cell's behavior is produced Therefore, the cellular signaling starts as soon as the first messenger (the ligand) binds to its receptor.
hope this helps
Answer:
Attached is an image go help you with this.
This phenomenon can be explained by Allen's rule. It says that the body proportions and shape may vary in different climates. The temperature decreases as the latitude increases, so in the northern region is much colder. Animals must preserve heat in such conditions. So, exposed surface areas of the body, such as the ears, feet, and tail, are usually minimized to minimize heat loss in the cold climate. <span>Therefore, northern species often have smaller ears, feet, and tail than the southern species. </span>
Light-independent reactions (dark reactions). Light reactions need light to produce organic energy molecules. Dark reactions make use of these organic energy molecules.
The number of times per week that exercise is performed is known as frequency.
Exercise frequency answers the question how many times you workout per week total. This includes weight training workouts, cardio workouts.This is value that can vary depends on many factors specific to individual (age, weight, condition). Because of this, it’s impossible to say exactly how often(how many times) everyone should be working out per week total.