Answer:
Cell theory refers to the idea that cells are the basic unit of structure in every living thing. Development of this theory during the mid 17th century was made possible by advances in microscopy. This theory is one of the foundations of biology.
Organisms such as producers who make their own food.
How to remember: "auto" means they make it automatically by their own.
Correct answer: A) Extension
Extension is a physical position that occurs when angle between the bones and the limbs of joint increases.
It takes place when there is a contraction of muscles and bones move the joint from a bent to a straight position, it is opposite of flexion, in which the angle between the bones and the limb at the joint decreases.
Example: During straightening of the leg, the angle between the tibia and femur increases, which shows extension has taken place.
