Answer:
The correct answer is: β1 adrenergic receptor activation. Increased in cAMP lead to increased amounts of Na influx (though if channels) and calcium influx of pacemaker cells. This increases the frequency of APs of the pacemaker and increases the rate of contraction.
Explanation:
cAMP generated in response to β1 adrenergic receptors,results in excitation contraction coupling by initiating PKA and causing phosphorylation of L type Ca2+ channels and ryanodine receptors. This increases the concentration of intracellular Ca2+ ions in atrial cells, ventricular cells and AV pacemaker cells. This increase in firing rate. As a result rate of contraction increases.
1. G. Tissue
2. C. Vascular Tissue
3. J. gametophyte
4. B. chloroplast
5. A. photosynthesis
6. F. cellulose
7. H. fertilization
8. L. cuticle
9. E. vacuole
10. K. chlorophyll
11. N. sporophyte
12. D. the cell wall
13. M. gamete
Answer:
I'm pretty sure the answer is 4.
Explanation:
1 and 2 are definitely homeostasis because it is a way to keep your body balanced how it needs to be and 3 would be a natural reaction that your body would make to prevent further pain, but 4 would be a personal choice that is made by the person who stays up.
First of, they are in two different phylum. Flat worms are in the planarian phylum while, Porifera is the sponges phylum. Sponge has no organs, and can reproduce asexually. Many flat worms are parasites while no sponges are. Another thing is sponges have no symmetry while flat worms have bilateral symmetry. Hmmm what else... on yes flat worms have one body opening while, i not 100% sure sponges have two.