They cool off the water or warm it up
Answer: If there is competition for food and nesting areas.
Explanation: Barred owls and spotted owls are well known as rivals. Barred owls are known to be aggressive towards spotted owls and are both bigger and more aggressive than them.
A
B
AB
O
unless you're asking for specifics, like O+ and such, but I think you just wanted the main four, so there you go. hope this helps, but I may be wrong ^^
Answer:
Hormones act as first messenger but not as second messengers.
Explanation:
Second messenger act as signaling molecule which are secreted in response to various biological signals generated by first messenger such as hormones,neurotransmitters etc.Second messengers include various bioactive molecules such as cyclic AMP(cAMP),cyclic GMP(cGMP),inositol triphosphate(IP3),diacylglycerol(DAG),calcium ions(Ca2+) etc.
Hormones are extracellular signaling molecules whereas second messengers are intracellular signaling molecules.