What might be the function of the muscle contraction in the walls of veins?

What role does differential reproduction play in natural selection? ! a) some organisms have different reproductive success due to nongenetic traits. b) some organisms have traits that them reach reproductive age. c) different methods of reproduction result in some organisms being genetically altered. d) reproduction varies among organisms due to pathogenic factors. the answer is not a or d based on other posts.

Lola needs to sign 6 invitations. using stopwatch that measures time to tenths of a second, it takes lola 5.3 seconds to sign her full name. going by the accuracy of the stopwatch, which is the most accurate determination for the number of minutes lola needs to sign all 96 invitations

The fruit of a certain plant is sweet and fleshy. the seeds of this plant have a seed coat that is fairly tough. the seeds germinate better if they are exposed to acid, or scarification. what is the most likely type of dispersal for this seed? water animal wind