Comparitve study of rat and human

The circulatory system of the rat and humans:

Both the rat and humans have a 4 chambered heart, which includes 2 atria and 2 ventricles. The circulatory system consists of blood, the heart and blood vessels.

·         Blood: connective tissue of liquid plasma and cells.

·         Heart: a muscular pump that circulates blood.

·         Blood vessels: include arteries, capillaries and veins that deliver blood to all tissues.



Rat heart is located near the top of the animal.

Human circulatory system, arteries are red, veins are blue.

A: right atrium

B: left atrium

The atria collect blood from the veins

C: Left ventricle

D: Right Ventricle

The ventricles pump blood out of the heart into the arteries

The digestive system of the rat and humans

·         The digestive system enables animals to break down food that they eat and obtain energy for other body processes.

Two differences between rat and humans

·         Rats don’t have a gallbladder, whereas humans do.

·         The rat has a large cecum, which is designed to break down harsh foods that the rat ingests, humans still have a cecum but it is smaller in comparison to the rat.

http://www.youtube.com/watch?v=z8FH_Mp54TE

Invertebrate compartive study

Movement and skeleton:

The earthworm has a hydrostatic skeleton and it moves by contracting its muscles and cilia.

The crayfish has an exoskeleton and to move it uses its walking legs and swimmerets.

Excretory system:

The earthworms excretory system consists of structural units called nephridium and they have their digestive tract to excrete waste.

The crayfishes excretory system is located at the base of antennae and it mainly removes ammonia.

Habitat and respiration:

The earthworm lives in moist soil and breathes through their skin.

The crayfish lives in freshwater environments and breathes through their gills.

Reproductive organs:

The earthworm is a hermaphrodite, meaning they have both female and male reproductive organs, but they do not mate with themselves.

The crayfish has one gender, either male or female.