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Towards modernisation

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Class 10 Class 12

Fill up the blank spaces appropriately.                                                                          

Phylum

Excretory organ

Circulatory organ

Respiratory organ

Arthropoda

a

b

trachea

c

Nephridia

closed

skin

vertebrata

d

closed

lung


 

Phylum

Excretory organ

Circulatory organ

Respiratory organ

Arthropoda

a. Malphigian tubules,

b Open

trachea

cAnnelida

Nephridia

closed

skin

vertebrata

d. Kidney

closed

lung


Give an example of
a. Roundworm
b. Fish possessing poison sting
c. A limbless amphibia
d. An oviparous animal


       


a. Ascaris
b. Trygon
c. Ichthyophis 
d. Platypus


Endoparasites are found inside the host body. Mention the special structures possessed by these to enable them to survive in those conditions.


The special structures possessed by endoparasites are as follows:
 
1. Hooks and suckers,
2. Dorsoventrally flattened body,
3. High reproductive potential, 
4. Indirect development.


On a morning  walk  with your friend you came across an animal which looks like a snake. But on watching it closely, your friend says it is an earthworm. What helped him in identifying it as an earthworm?                                                                                                             


The following characteristic helped to identify it as an earthworm 

Body elongated and metamerically segmented, the presence of prostomium, characteristic mode of locomotion.


1.In order to eradicate mosquitoes Housing colony members were asked to keep the surroundings dry, not to let water standing any where and cover the drainage. It was found that the strategy worked and there was decline in the number of mosquitoes.What according to you is the reason for the decline in the number of mosquitoes.?


Mosquito belongs to class Insecta, phylum Arthropoda . Its development is indirect with distinct stages like egg, larva,pupa and adult. It breeds in water. Since water is not provided, it cannot complete its life cycle . This leads to the decline in the number of mosquitoes.