Because it has to be that way
Answer:
In North America, around June 21, Earth tilts on its axis toward the sun, which is Summer Solstice and when the Northern Hemisphere has the most daylight of any time of year. Winter solstice the Northern Hemisphere tilts the farthest away from the sun and when we have the least amount of daylight of any time of the year.
Explanation:
As Earth revolves around the Sun, it rotates on its axis. Sometimes Earth tilts toward the Sun which is when Summer occurs. In the Winter Earth tilts away from the Sun.
ATP is like a charged battery, while ADP is like a dead battery. ATP can be hydrolyzed to ADP and Pi by the addition of water, releasing energy. ADP can be "recharged" to form ATP by the addition of energy, combining with Pi in a process that releases a molecule of water.
Do you want the definition ?
Answer:
The correct answer is The cells do not have proper receptor.
Explanation:
During paracrine signaling a signaling molecules are generated from one cell.The generated signaling molecule then binds to the receptor of neighboring cell to carry specific signal from donor cell to the acceptor cell.
But the signaling molecules will not bind to the cell that is producing it because that producing cell do not contain proper receptor to bind that signaling molecule.
The binding of signaling molecule to the receptor of its producing cell occur during autocrine signaling.