the
All living organisms, from the simplest prokaryotes to
most complex eukaryotes, have excellent ability to sense their
environment. They respond to various physical, chemical and
biological stimuli.
The various external factors to which living organisms respond
are light, water, temperature, pollutants, other organisms,
Light duration or photoperiod affects many seasonal
breeders, plants as well as animals. All living things respond
to chemicals entering their bodies. Humans are superior to
all living things as they have an additional ability of
self-consciousness. Therefore, consciousness can be
considered as a defining property of living organisms.
However, in human beings, it is difficult to define living
state, in certain situations like if patients lying in coma
supported by machines that replace heart and lungs are
brain-dead with no self-consciousness.
6. Body Organisation
The body of living organisms is organised, i.e., several
components and sub-components cooperate with each
other for the functioning of whole body.