Most of the time m (M) means male and f (F) means female.
The correct answer is: D, a decreased number of oxygen-rich mitochondria.
Motor neurons are involved in the skeletal muscle contractions in vertebrates, as the process is a synaptic one. These occur due to a conscious effort by the brain, from which these signals originate. In some reflexes, the signal originates from the spinal cord.
Answer:
Excretion is a process by which metabolic waste is eliminated from an organism.
