Answer: a. endoderm-bone
Explanation: In the context of embryonic development, bone tissue may arise from several precursor cell populations, such as the neural crest (some facial bones), lateral mesoderm (bones of the limbs, among others), and paraxial mesoderm (vertebrae and part of the skull). There is no evidence to suggest that any of the bony structures is derived from the endoderm germ layer.
All of them. Forests are considered natrual enviornment and people/buildings are man-made environment
sorry for bad spelling
Answer:
A. insects fly around a bright lamp at night
Explanation:
insects are naturally attracted to light due to presence of positive phototaxis. Insects revolve around the light in the same way as electrons do around the nucleus.
Well, there are two kinds of organisms: osmoregulators, that can regulate the level of salt and the salinity does not affect them (an example is salmon: for salmon this sentence is true. Generally, for most fish this sentence is true)
However, for some species, such shark - osmoconformers - this is false: they are affected by the salinity. in general I would conclude that This is false: the marine salinity DOES affect the fish (and other organisms) living there.