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.
Cant see the following animals
Answer:
<h2>C. To date rock layers</h2>
Explanation:
<em>They can help determine the relative age of rock layers</em>.
Answer: Option A
Explanation:
A paraphyletic group can be defined as the group of organism that includes the ancestors but not all of its descendants.
There are three kinds of phylogenetic groups that can be understood by the help of the diagram.
The phylogeny can be defined as the diagram which shows the evolutionary relationship of one organism from another.
Other groups are monophyletic groups, parsimonious et cetera which shows different evolutionary relationship with organisms.
Ecologist let me know if you need all the answers
