A chemical or secretions which are thrown outside the body for transmitting message to the individual of same species is________?

Certification is not required for________?

To pack with clay material generally for the purpose of checking leakage of water is called ________?

Diversity of animals and crop species in different ecosystems is called as________?

A fixed reference point from which the discharge of flowing water is measured is________?

Khosla provided a seepage theory for design of Hydraulic structures called________?