Cephalization is the differentiation of end part of the body into a head in which nerve tissue is concentrated. Sponges have a very loose nervous system and their cells work individually, not controlled by a nervous system. Since they have no defined head as a consequence of concentrated nervous system, the sponges could not have cephalization either.
1) Arithmetic density- the number of people per square unit of land
2) Physiologic density- Is the number of people per square unit of farmland.
3) Agricultural density- is the number farmers per unit of farmland.
Following precautions should be taken when constructing;
1)
Contractors should know about the temperature on
the work site.
2)
The unsatisfactory decision of safety measure
strategy will crumple the particular undertaking quality.
3)
There should be the availability of LP gas
heaters and blowers.
4)
Temporary workers can likewise pick poly fenced
in area installed with platform frameworks firmly.
5)
Warmth conveying punctured texture tube running
under platform will be utilized.
6)
There should be the utilization of dry mortar
rather than wet mortar in winter season.
7)
Quick setting mortar or cement Mortar setting
admixtures can be utilized.
8)
Wind should be above 25mph in wind barriers and
the temperature that is required is below 25 degree.
I think the best medium is agar. It is a jelly-like substance that is obtained from algae, and is used to culture small organisms such as microorganisms and bacteria.
Hope this helps. :)