c), mitosis; meiosis ... Which of the following statements about human reproduction is true? ... b), Each cell undergoing mitosis divides into two complete new cells that are ... a), Sperm and ova are not identical to the parent cells that produced them. ... a), Mitosis produces cells that have a haploid number of chromosomes.
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.
Answer
True
Explanation:
The temperature in the bathypelagic zone, unlike that of the mesopelagic zone, is constant.
I believe its A. I may be wrong.
Cell
Tissue
Organ
Organ System
Organism
