Support, Movement and Growth in Animals (9)

The way the earthworm moves (3)

The chaetae on the body of the earthworms will grip the ground

The way the earthworm moves (4)

At the same time, the other segments will become longer and thinner

The way the earthworm moves (5)

This occurs because the circular muscles at these segments contracts and the longitudinal muscles relax

The way the earthworm moves (6)

The chaetae at these segments will release the grip to allow the body of the earthworm to lengthen and move forward

Vertebrates animals that have endoskeleton

Vertebrates that have endoskeleton are divided into terrestrial vertebrates, aquatic vertebrates, and birds

Factors that cause terrestrial vertebrates need a strong and firm skeleton (1)

To support the body

Factors that cause terrestrial vertebrates to need a strong and rigid skeleton (2)

Terrestrial animals have a big skeletal frame that is compatible to their body

Factors that cause terrestrial vertebrates to need a strong and rigid skeleton (3)

The body weight of the terrestrial vertebrates is supported especially by the pectoral girdle and pelvic girdle

Endoskeleton of an elephant

Factors that cause terrestrial vertebrates such as elephant needs a strong pectoral girdle and pelvic girdle

To support its body weight