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.
<span>hello there hester , i would say needed to form cell membranes</span>
The remains are called fossils. Fossils are remnants of animals, plants, or microorganisms that have been solidified in the process of fossilization, where the organism is surrounded by sediment, minerals, and other solid objects which are compressed and heated around the organism over time. This forms a solid mass with the preserved organism inside, other known as a fossil.
Heart,vessels,circulating fluids