The answer is Catecholamine. It is any of a class of aromatic amines that includes a number of neurotransmitters such as epinephrine and dopamine. The adrenergic receptors are a class of G protein-coupled receptors that are targets of the catecholamines, especially norepinephrine (noradrenaline) and epinephrine (adrenaline). These three - catecholamine, peptide hormones and eicosanoids acts as extracellular membrane receptors which means that these receptors are embedded in the membranes of cells. They act in cell signaling by receiving (binding to) extracellular molecules.
<span>The answer is Haploid spores germinate to give rise to protonema, which later develops into a sporophyte.</span>
A protonema (plural: protonemata) is a
thread-like chain of cells that forms the earliest stage (the haploid phase) of a bryophyte life
cycle..
<span>A haploid gametophyte ( each of whose cells contains a fixed number of
unpaired </span>chromosomes) gives rise to a <span>diploid sporophyte</span>,.
Gametophytes produce haploid sperm and eggs which fuse to form diploid zygotes
that grow into sporophytes.
<span>The average human red blood cell is roughly 6 to 8 micrometers wide. The width of a pin is this problem is defined as 1000 micrometers. Assuming we use the smallest size of a blood cell, then we divide 1000 by 6, and we find that roughly 166.66 (or 166 if you are rounding down) red blood cells will fit.</span>
