Vascular endothelial growth factor (abbreviated vegf and pronounced "veg-f") is a peptide signaling molecule related to platelet-derived growth factor. vegf is important in the formation of the circulatory system because its signaling pathway causes the formation of blood vessels in developing embryos during normal development. tumors also produce and secrete vegf, causing nearby blood vessels to branch and grow to form new blood vessels that supply these tumors.
given what you know about the different kinds of cell signaling and vegf, which statement is true?
vegf is a paracrine signaling molecule because it binds to receptors on nearby cells, at the site where new blood vessels are needed.

Nasa scientists must work together to make sure that everything is correct and accounted for when launching a shuttle. besides a physicist, what other type of scientist would be in making sure that the shuttle has the appropriate type and amount of fuel to reach its destination?

During endocytosis, cells expel what they don't need take in what they need shrink due to loss of water

Which statements best describe the differences or similarities between a comparative investigation and an experimental investigation? check all that apply. experimental investigations are best for showing cause-and-effect relationships, while comparative investigations do not necessarily show this type of relationship. comparative investigations are often impractical and unrealistic, while experimental investigations are the most practical and realistic kinds of investigations. comparative investigations allow for the use of a wide range of variables but do not have a control group, while experimental investigations involve variables that can be controlled. both experimental investigations and comparative investigations are designed to answer scientific questions. both experimental investigations and comparative investigations focus on making observations rather than collecting new data.