Viruses, bacteria, fungus,Protozoa and worms
Muscles are required in breathing, talking, running, walking, and any body movement. Actin and myosins are protein filaments present in muscle cells that help to contract and relax or change the shape of muscles. Muscles are responsible for the movement or motion of organisms. Joints are the connection between two or more bones. Most joints are mobile.
Muscle strength is determined by several factors. Some of those are the physical shape, size, and innervation of the muscles.
Weak contraction
- Potassium accumulates in the sarcoplasm.
- Contracted lower sarcoplasm pH.
- Begin contraction with muscle already 50%.
- The circular arrangement of muscle fascicles.
Stronger contraction
- Increase in muscle belly circumference.
- A lesser proportion of motor neurons to muscle fibers.
- Increased recruitment.
- Increased stimulus frequency.
C) they are passed onto offspring
All of Darwin's selections are based upon the tenet that they are heritable, which is to say passed from one generation to the next