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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

what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
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 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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