Answer:
The osteoblasts, which should have been building the new bone
Explanation:
Bones are the one of the types of connective tissues and have hard extracellular matrix. Osteoblasts are the cells that serve in formation of extracellular matrix of bones as these cells secrete collagen fibers and inorganic salts present in the matrix of bone. Hence, if a bone is not able to heal after fracture, osteoblast cells should be checked for their activity.
The heart’s electrical system is responsible for making and conducting signals that trigger the heart to beat. These signals cause the heart’s muscle to contract. With each contraction, blood is pumped throughout the body. This happens 24/7 without us having to monitor it all the time so that our heart does not stop.
Answer: Option (1)
Explanation:
The extinction event played an important role in the creation of new diverse life forms on earth. After an extinction event, both globally and locally, more than 75% of animal species gets vanish and the only those highly resistant life supporting organisms survive and with due course of time, they undergoes evolution, thereby bringing changes to the existing life forms. This is how they initiates and helps in the increasing species diversity.
Thus, the correct answer is option (1).
There is no answer ,you wrote the answers with the question
