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  • This skeleton is found inside the body and can consist of bone (vertebrates) or cartilage (sharks).


  • Endoskeletons consist of living tissue - so it is able to grow steadily within the animal enabling some to reach a large size.
  • It can support the weight of a large animal
  • the skeleton is jointed which allows for flexible movement and support
  • muscles attach directly to the skeletal bones to allow for movement and support
  • vital organs are protected by bone cavities like the ribcage and the pelvic girdle
  • lends itself to adaptation to the environment Vertebrates move in differet ways ( e.g. running, jumping, swimming, flying.)


  • Lack of mineral elements like calcium and phosphates will cause brittle bones and affect movement and support
  • Lack of vitamin D in the diet results in a condition/disease caused rickets. A disease characterised by bowed legs.

Developmental progression and why skeletons are needed for terrestrial life

Problems that animals moving from water to land had to overcome

  • Loss of body support provided by water

Water is about 1000 times denser than air and is a much more resistant medium to move through, its high density buoys up the body providing support.. One of themajor problems by animals moving from water to land was the increase in the force of gravity. In order to counter this, animals needed to develop stronglimbs and to adapt the skeleton to support their body weight on land.

  • Locomotion

Moving effectively on land is essential particularly if one needs to avoid predator, catch prey or adapt to a particular habitat.

  • Desiccation

Exposure to air results in evaporation of water from breathing organs and body surface. If this problem is not overcome animals will be confined to damphabitats

Constancy of temperature

Natural bodies of water do not show much temperature fluctuation, whereas on land, the range and fluctuation in temperatures can be large. This can causehuge problems for animals which have no temperature control mechanisms.

  • Gaseous exchange

Gills depend on water flow or movement through water to operate. To survive on land a completely new mechanism of breathing needed to evolve.

  • Opportunities for breeding on land

The provision of safe shelter for the protection of vulnerable eggs and young is far easier on land than in water habitats.. The main problem here was to findmethods of reproduction which did not require fertilization in water

  • Variety of habitats

On land there are a tremendous variety of habitats e.g. tropical, coniferous and temperate forests, grasslands, deserts, mountains, oceanic islands and polarregions. Aquatic habitats, despite being far less diverse contain the greatest number and variety of living organisms on earth. Each habitat will havedifferent requirements with regard to access to food,, shelter, protection from enemies etc.

The exoskeleton in terrestrial arthropods

Arthropods moved onto the land long before the vertebrates emerged and a major factor in their success was the exoskeleton.

  • Highly protective without sacrificing mobility
  • Provides attachment for muscles which control movement of appendages
  • In insects and spiders it is impregnated with waxes forming a waterproof barrier which prevents drying out.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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why and for what was five kingdom of classification of organisms introduced
give the ans as fast as possible
Comment on the ozone depletion over the period of 1982 to 1996
Mpho Reply

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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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