High school students in India under the CBSE Board are taught that consciousness is a defining property of living organisms. This question lies under the topic of 'What defines living organisms?' Does that mean that if robots and other artificial intelligence have consciousness and can react to some external stimuli (just like plants), they are alive? Also, what about the patients in coma or those who are 'brain-dead', are they alive or dead?
Then, how do we define living in terms of science?
A possible answer in my opinion to the second question above could be that life begins at conception and an organism is considered alive till the point where it has no differences with the dead; i.e. a person who is 'brain-dead' would still be considered alive because he/she still isn't the same as a dead person.
So should consciousness be a defining property of living organisms?
Edit: Defining Consciousness-
In the NCERT textbook which is used to teach the CBSE high school students in India, consciousness is explained as the ability to sense the surroundings or environment and respond to the environmental stimuli which could be physical, chemical or biological.
For reference: NCERT Class 11 Biology Textbook~ Unit 1: Chapter 1, Page 5 (second paragraph) Link to book: 1http://ncert.nic.in/textbook/textbook.htm?kebo1=1-22