True.
Explanation:
Cardiac muscle and some types of smooth muscle have the ability to contract without any external stimuli.
These muscles are called involuntary muscles.
Involuntary muscle are named so because,these muscles are independent of voluntary control and are controlled by our autonomic nervous system.
These are also known as white or smooth muscle.
Examples, muscles of heart, muscles of alimentary canal etc.
Answer: Option D.
Explanation:
The process of bone thickening starts with the formation of a template of the hyaline cartilage diaphysis from chondrocytes. Due to developmental signals the bone matrix begins to calcify. This calcification allows the prevention of nutrition diffusion into bone matrix and opens the cavities in diaphysis cartilage. Blood vessels enters into the cavities and osteoblasts and osteoclasts modifies calcified cartilage matrix into spongy bone. Osteoclasts allows the break down of spongy bone and forms a medullary cavity in diaphysis. Irregular connective tissue forms a periosteum (covers compact bone) around the bones and allows the attachment of bone to tissues, tendons, and ligaments. The bone then continues to grow and get thick.
Hence, the correct option is D.
C. That is the ring of fire
Answer:
China has been the source of many innovations, scientific discoveries and inventions. This includes the Four Great Inventions: papermaking, the compass, gunpowder, and printing (both woodblock and movable type).
