Excretion and Locomotion

Excretion is the removal of metabolic wastes.

These wastes result from chemical reactions in the body. (Metabolism)
Examples would be carbon dioxide from respiration and nitrogenous wastes from protein metabolism. Organisms will use their environment to the best advantage to remove these wastes.

Adaptations for Excretion

Potists (Ameba) and Coelenterates (Hydra)
Carbon Dioxide and nitrogenous wates (AMMONIA) diffuse out across the cell membrane

Annelid (Earthworm)
Diffusion of Carbon dioxide through moist skin. Removal of nitrogenous watse (UREA) through NEPHRIDIA, a primative kidney.

arthropod (Grasshopper)
Diffusion of Carbon dioxide out the Spiracles that are connected to the Tracheal Tubes. Removal of nitrogenous wastes (Uric acid) through Malphigian Tubules. This saves water for the arthropod because uric acid is not soluble in water.


Lungs with alveoli to remove carbon dioxide from the blood. Kidney and skin to remove nitrogenous watses (UREA) from the blood. The functional unit of the kidney is the Nephron. Most filtration occurs in the Bowman's Capsule of the nephron where urea is excreted. Most reabsorption occurs in the tubule where "good stuff" is absorbed back into the blood. This allows for regulation of blood pressure by monitoring blood volume.
Which of the other representitive organisms has urea as it's principal nitrogenous watse product?

Open Ended Question

Excretion: Explain why an organism like the hydra doesn't need a special excretory system.
Explain why the kidney may perform active transport.
Note the relationship between and organism's environment and it's adaptation for excretion.


There are many advantages to motility. It helps the organism to find food, mates and escape predation. Organisms that do not move are sessile. Examples: Plants, barnacles and most of the time Hydra




Pseudopods "false feet"


check out the mad scientists view of Cillia "small oars"


Flagellum "one long hair"

Coelenterate (Hydra)

Can somersault but mostly sessile


Circular and longitudinal muscle with bristle like Setae that act as "ski poles"


Chitinous appendages with legs and wings


There are many types of connective tissue. Each is classified by the material between the cells called a matrix. Even blood is catergorized as a connective tissue with a liquid matrix.

Bones that work as levers with your voluntary skeletal muscles
Tendon acts as a muscle to bone connection (MTB)
Ligament acts as a bone to bone connection (BLB)
Flexors are muscles that make the angle of a joint smaller. (BICEPS)
Extensors are muscles that make the angle of a joint larger. (TRICEPS)

Open Ended Qusetions

Explain why a motile organism has advantes over a sessile organism. List what these advanteages are.
Compare and contrast a ligament and a tendon