SUPPORT AND LOCOMOTION

ADAPTATIONS FOR LOCOMOTION

Locomotion:• Many types of living things are able to move on

their own from one place to another.• Being able to move oneself from place to place

is called locomotion.• Organisms that are capable of locomotion are

said to be motile.• Although not all animals are motile, most

animals and many protists are motile. On the other, plants are not motile.

Being able to move from place to place offers a number of advantages for an organism.

• Locomotion makes it easier for organisms to get food

• Locomotion allows organism to find suitable places to live and to move away from harmful conditions in the environment.

• Locomotion allows organisms to escape enemies or toseek shelter.

• Locomotion allows organisms to find mates and reproduce.

MUSCLES AND SKELETONS• In all but the simplest animals, locomotion uses

both muscles and a skeleton to which the muscles are fastened. Muscles can exert force when they contract, or shorten. When they contract, they move the parts of the skeleton to which they are fastened.

SKELETONS

EXOSKELETON ENDOSKELETON

EXOSKELETON ENDOSKELETON

It is found outside the body, enclosing the soft parts.

It is found inside the body and does not protect the animal as well as an exoskeleton

Some protists and most invertebrates have exoskeleton

Vertebrates have endoskeleton

Mostly made of chitinMade of bone and cartilage

(two types of connective tissue)

Because they are not made of living cells, they cannot grow. For this reason from time to time, arthropods molt their exoskeleton and replace them. (During the time between molting and growth of the new exoskeleton, the animal’s soft body is unprotected)

Bones and cartilage contain living cells, and can grow the skeleton grows larger along with the rest of the animal.

They serve as the site of attachment for muscles Skeletal muscles are fastened to the endoskeleton, making the movements of body parts

Clams, oysters, mollusks have hard shells with calcium compounds, crabs, spiders, insects and other arthropods have exoskeleton made of chitin

Fish, amphibians, reptiles, birds and mammals have endoskeleton

http://buzz.ifas.ufl.edu/830pe3j.jpg

LOCOMOTION IN PROTISTS

An amoeba (Amoeba proteus) using two pseudopods (false feet) to capture Staurastrum brachiatum.

PSEUDOPODS

LOCOMOTION IN PROTISTS

CILIA

FLAGELLA

LOCOMOTION IN PROTISTS

LOCOMOTION IN THE HYDRA

• The presence of mucus secreting cells and ameboid cells allow it to glide along on its base.

•It can move quickly by somersaulting its base completely over its tentacles.

•It can also inch along by bending over and fastening its tentacles to an object and then pulling its base closer.

•The hydra can float upside down in the water by making an air bubble on its base.

LOCOMOTION IN THE EARTHWORM

Within its body wall are two layers of muscles.

1. An outer layer of circular muscles goes around the worm.

2. An inner layer of longitudinal muscles goes along the full length of the body.

When the circular muscles contract, the worm becomes longer and thinner. When the longitidinal muscles contract, the body becomes shorter and thicker.

LOCOMOTION IN THE GRASSHOPPER