The skeletal system.
The Prawn
Describe its skeletal system- what were some key features of it?
The prawn had a head, body and tail, all of which were covered by a thin, but hard shell. This shell was made up of different segments which allowed the prawn to move. The prawn had no bones inside it's body.
What role does the skeleton perform for the prawn?
The shell around the outside of the prawn is used to hold the rest of the body together and give it structure and support. It also acts as a coat of armor to protect the inside of the prawn, so if it comes into contact with anything the shell will get damaged rather than the important organs inside.
What other kinds of animals have this type of skeletal system?
This type of skeletal system (an exoskeleton) is found in other crustaceans such as crabs and lobsters, insects, spiders and turtles and tortoises.
How is it different to our skeletal system?
The obvious difference is that ours is inside the body, and theirs is outside the body. Another difference is that endo-skeletons are living tissues and require nutrients from the body, whereas exoskeletons like the prawns aren't.
What are some benefits of this kind of skeletal system?
The exoskeleton covers the whole body- it's muscles, organs, fat, nerves and so on. It is a layer of shell that provides reliable protection for the entire body, unlike the endo-skeleton which only really protects the vital organs. The shell is flexible and adaptable. Since the exoskeleton is not living nutrients and energy isn't wasted on supplying for the shell, and can be used in the body instead. The shell also helps prevents desiccation which is where the body dries out.
What are some disadvantages of this kind of skeletal system?
There are many disadvantages of an exoskeleton. Firstly, it cannot grow, so the animal must molt out of its shell until a new one develops. It is very exposed and vulnerable, and prone to attack from predators. Because exoskeletons are external, the limit the growth and development of muscles and tendons inside the body. It is also a lot heavier than an internal skeleton.
How might it grow?
When a prawn grows, it's shell wont. When the prawn gets too big for it, the shell must be shed, or molted and another shell will begin to grow. The frequency of molting depends on the size, age and gender of the prawn.
What is this kind of skeletal system called?
This kind of skeletal system is called an exoskeleton. It is an external support structure.
What is this kind of skeleton made of?
This kind of skeleton is made of chitin- a tough, protective substance made of calcium.
The prawn had a head, body and tail, all of which were covered by a thin, but hard shell. This shell was made up of different segments which allowed the prawn to move. The prawn had no bones inside it's body.
What role does the skeleton perform for the prawn?
The shell around the outside of the prawn is used to hold the rest of the body together and give it structure and support. It also acts as a coat of armor to protect the inside of the prawn, so if it comes into contact with anything the shell will get damaged rather than the important organs inside.
What other kinds of animals have this type of skeletal system?
This type of skeletal system (an exoskeleton) is found in other crustaceans such as crabs and lobsters, insects, spiders and turtles and tortoises.
How is it different to our skeletal system?
The obvious difference is that ours is inside the body, and theirs is outside the body. Another difference is that endo-skeletons are living tissues and require nutrients from the body, whereas exoskeletons like the prawns aren't.
What are some benefits of this kind of skeletal system?
The exoskeleton covers the whole body- it's muscles, organs, fat, nerves and so on. It is a layer of shell that provides reliable protection for the entire body, unlike the endo-skeleton which only really protects the vital organs. The shell is flexible and adaptable. Since the exoskeleton is not living nutrients and energy isn't wasted on supplying for the shell, and can be used in the body instead. The shell also helps prevents desiccation which is where the body dries out.
What are some disadvantages of this kind of skeletal system?
There are many disadvantages of an exoskeleton. Firstly, it cannot grow, so the animal must molt out of its shell until a new one develops. It is very exposed and vulnerable, and prone to attack from predators. Because exoskeletons are external, the limit the growth and development of muscles and tendons inside the body. It is also a lot heavier than an internal skeleton.
How might it grow?
When a prawn grows, it's shell wont. When the prawn gets too big for it, the shell must be shed, or molted and another shell will begin to grow. The frequency of molting depends on the size, age and gender of the prawn.
What is this kind of skeletal system called?
This kind of skeletal system is called an exoskeleton. It is an external support structure.
What is this kind of skeleton made of?
This kind of skeleton is made of chitin- a tough, protective substance made of calcium.
THE WORM
What kind of skeletal system does the worm have?
The worm has a hydro skeleton. Some other cold blooded/soft bodied animals have this kind of skeleton are jellyfish, sea urchins and starfish!
How does it work?
A hydro skeleton is a water/fluid filled cavity surrounded by muscles. This is called a 'coelum'. It acts as a flexible, buoyant support system for the animal.
The worm has a hydro skeleton. Some other cold blooded/soft bodied animals have this kind of skeleton are jellyfish, sea urchins and starfish!
How does it work?
A hydro skeleton is a water/fluid filled cavity surrounded by muscles. This is called a 'coelum'. It acts as a flexible, buoyant support system for the animal.
THE CUTTLEFISH
Describe the cuttlebone.
The cuttlebone is a hard, white plate that is almost an oval shape, but thicker at one end. It is hard so it cannot be snapped although you can scratch into it.
What would its main role be?
Its main role would be to give structure to the end of the cuttlefish
What is it made of?
The cuttlebone is made of calcium carbonate which is found in many rocks and shells, including pearls and eggshells! It is sometimes used as a calcium supplement in medicines.
Is it an internal or external system?
It is an internal skeleton as it is inside the body.
The cuttlebone is a hard, white plate that is almost an oval shape, but thicker at one end. It is hard so it cannot be snapped although you can scratch into it.
What would its main role be?
Its main role would be to give structure to the end of the cuttlefish
What is it made of?
The cuttlebone is made of calcium carbonate which is found in many rocks and shells, including pearls and eggshells! It is sometimes used as a calcium supplement in medicines.
Is it an internal or external system?
It is an internal skeleton as it is inside the body.