From lowest to highest hierarchy it would be: planet, star, solar system, galaxy.
Answer: muscle contraction of sustained force resulting from repeated action potentials. (Option A)
Explanation: Tetanus is also called physiologic tetanus. Tetanus refers to the contraction of the muscle, which is established when the motor nerve that supply nerves to a skeletal muscle produces action potentials at a very high degree.
However, tetanic contraction is usually a normal process (such as when carrying a heavy box). Also, muscles can be shorten, lengthen or remain constant length during tetanic contractions.
Energy is ever-existing - energy does not disappear or is not created from nothing. Energy is only transferred from one system to another. Energy is only transformed from one type/form of energy to another type/form of energy. So, the energy of a system is either converted into another type of energy in that same system or is extinct to another system.
Answer: Stabilization selection
Explanation:
Natural selection involves the differential survival and growth of organisms which have suitable traits to survive in unfavorable or adverse environment. Such traits are passed on to the next generation. Stabilization selection is a type of natural selection in which the nature selects the non-extreme phenotypic traits. Middle traits are selected and such organisms grow and reproduce. Example can be given that of human babies in which babies with low weight lose more heat and babies with high weight are difficult to be delivered from the pelvis. Therefore, babies with middle weight are expected to survive more than that of low or middle weight.
