The purpose of the coenzymes NAD and FAD is to essentially carry hydrogen ions to the stage of cellular respiration called oxidative phosphorylation, I believe.
Answer:
Neutron-capture inside stars.
Explanation: Although there are other minor contributions they are not only produced in stars that explode in supernova.
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.
It has very thick fur or hide so it cant be stung by bees's, except for its nose. Also its very resistant to Poison from snakes and scorpions. That would be my answer out of these 2 <span />
Ferns make their own food. They grow and reproduce using spores instead of things like seeds. Humans on the other hand have to ingest food from their surrounding and when mature reproduce sexually. They can also choose if they want to reproduce or not while ferns don't have that option. Sexual reproduction is based on inseminating and egg cell, while ferns don't worry about this because the spores just fall on the ground.
