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What does this mean?

Cambrian explosion refers to the tremendous increase in the number and type of multicellular organisms at the start of the Cambrian period of the Paleozoicera. Ancestral forms of all organisms emerged then, which have gradually changed to become the life forms we see today.

Cambrian explosion: explanation http://www.fossilmuseum.net/Paleobiology/CambrianExplosion.htm

Significant changes have taken place in all groups of plants and animals.


From being purely aquatic, plants gradually colonized land and had to cope with life in a completely different medium. They had to develop several structuralchanges, such as:

  • They developed true roots, stems and leaves with different tissues in these organs. Some plants developed flowers and fruit.
  • They developed supporting tissue like xylem and thick secondary walls with lignin.
  • They developed a means of protecting themselves against dehydration, such as the development of a cuticle and sunken stomata.
  • They became less dependent on water for fertilization, using wind and or animals to transfer pollen grains with sperm nuclei.


Animals also became more complex than their primitive ancestors. Some colonized land and had to make further changes.

  • They developed a head with a brain and limbs on both sides of the body.
  • The digestive system became more complex, developing a gut with two openings and various glands associated with digestion.
  • They had to protect themselves against dehydration, so many developed internal breathing systems, protecting the delicate lungs.
  • Birds and mammals became endothermic, i.e. able to keep their body temperatures constant despite changes in environmental temperature.

See: http:www.khanacademy.org/video/introducti-to-evolution-and-natural- election?playlist=Biology

Questions & Answers

anyone know any internet site where one can find nanotechnology papers?
Damian Reply
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Comment on the ozone depletion over the period of 1982 to 1996
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Source:  OpenStax, Siyavula: life sciences grade 10. OpenStax CNX. Apr 11, 2012 Download for free at http://cnx.org/content/col11410/1.3
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