Page 68 - Science Class 07
P. 68
BREATHING IN OTHER ANIMALS Cockroach
You have studied about the respiratory system Cockroaches neither respire through the
of human beings. Like human beings, animals process of diffusion nor they have lungs. They
also respire. They also take in oxygen during have a system of tubes called tracheae.
inhala on and give out carbon dioxide. But, the Tracheae have small openings called spiracles.
way or the mechanism of respiratory process Air enters in their body through spiracles.
varies from animal to animal. It is because they These spiracles are present on either side of
live in different habitats and they have adapted the body.
to prevailing condi on of their habitats. The Spiracle
structure of their respiratory organs are also
Tracheal Cercus
quite different. trunk
Let’s study about some of them:
Amoeba
Amoeba is a unicellular organism. However, it
also carries out different life processes which
also include respira on. Amoeba lives in fresh
water. The outer covering of its body has
Respira on in Cockroach
plasma membrane through which oxygen
Fishes
present in water diffuses into its body. Besides,
it also breathes out CO through plasma Fishes and several aqua c animals have gills,
2
membrane. In this way, the process of which permit the exchange of gases with the
respira on is carried out by amoeba. surrounding water. These gills are covered by
an operculum made up of filaments richly
supplied with blood. A fish takes in water
through its mouth, its water passes through the
gills where oxygenated water gives oxygen to
the blood. A pumping mechanism then carries
the oxygenated blood through out the body of
the fish. Similarly, gills give out carbon dioxide
Respira on in Amoeba when water passes out from the walls of the
operculum.
All the unicellular organisms do not have
respiratory organs. They take in oxygen and Gill Arch
give out carbon dioxide through the process of
diffusion.
Earthworm
Earthworms have moist skin through which air Water flow
enters inside and again comes out by the into mouth Operculum
process of diffusion. They do not have special
Respira on in Fish
respiratory organs.
68 Science-7
