The body constantly makes new cells for the purposes of growth or the replacement of old, damaged, or recently dead cells.
Answer:
d. all endothelial cells would be venous
Explanation:
The Notch signaling pathway is a cell signaling system which consist basically of 4 NOTCH genes ( NOTCH1, NOTCH2, NOTCH3, and NOTCH4) each of them having the information to build a particular cell membrane receptor protein.
It has been demonstrated in zebrafish embryos that Notch signaling are highly determinant factors during vascular development, and a key function of these genes was specifically to regulate the differentiation of arterial fate in endothelial cells.
Notch signaling-deficient embryos showed a loss of expression of arterial markers such as ephrinB2 from arterial vessels with an accompanying expansion of venous markers into normally arterial domains. In contrast, embryos in which Notch signaling had been ectopically activated, meaning an activation out of "proper" place (where not expected, e.g. venous endothelial), exhibited the contrary phenotype, this is a suppression of vein-specific markers with ectopic expression of arterial markers in venous vessels.
To summarize, when Notch is supressed (in this case inhibited with a specific Notch inhibitor) arterial fate of endothelium is not followed, and venous fate is stablished. Thus, endothelial cells (those expected to form venous tissues but also arterial ones) would specified as venous.
The opening and closing of ligan-gated ion channels
Answer:
(2) 988.5 mb.
Explanation:
The air pressure descends as we ascend. In other words, they are inversely proportional.
The air pressure descends as we ascend the mountain because the air molecules that are above us in high altitudes are fewer than the number of air molecules that are above us in the base of the mountain. So, the exerted pressure of the molecules on ourselves is lower in high altitudes.
Due to the reason mentioned above, we can deduce that the only correct option is option number two since the other ones show increasing or the same pressure, which is not possible as we ascend.
