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.
Answer: circulatory is when ur blood circulates and respiratory is the system we use to breath if I remember correctly
Explanation:
It was used till the 1960s. Hope i helped.
Answer:
oligodendrocytes
Explanation:
Glial cells are part of the nervous system. These are helper cells that support the function of the central nervous system (CNS) and can be called oligodendrocytes when they supply myelin to neurons. These cells are responsible for producing the myelin sheath have the function of electrical insulator for CNS neurons. They have extensions that wrap around the axons, producing the myelin sheath.
It is estimated that there are 10 glia cells in the CNS for each neuron, but because of their small size, they occupy half the volume of nervous tissue. They differ in form and function and they are: oligodendrocytes, astrocytes, Schwann cells, ependymal cells, and microglia.
