Types of Skeletons Flashcards
1
Q
What are the types of skeletons?
A
- hydrostatic
- exoskeleton
- endoskeleton
2
Q
What does a hydrostatic skeleton consist of?
A
- fluid-filled, closed chamber/s inside the body, that provide support against which muscles can contract to bring about movement
3
Q
Which animals have hydrostatic skeletons?
A
- soft bodied invertebrates
- jellyfish
- sea anemones
- annelids (earthworms)
- nematodes (roundworms)
4
Q
What are the advantages of hydrostatic skeletons?
A
- help to cushion internal parts from shock
- change shape
5
Q
How do animals with hydrostatic skeletons move?
A
By contracting the muscles surrounding the fluid-filled cavity which creates pressure that causes a change in shape
6
Q
What are the disadvantages of hydrostatic skeletons?
A
- lack well developed skeletal defense mechanisms
- restricted range of movement
- confined to water/near water
- cannot reach great size
7
Q
What does an exoskeleton (arthropod) consist of?
A
- made from the polysaccharide chitin
- light and quite strong
8
Q
What are the advantages of an arthropod exoskeleton?
A
- supports animal and protects internal organs from injury
- has muscles attached to knobs and plates so it allows for movement
- has joints where the exoskeleton is thin and flexible, enabling the animal to move easily
- covered with a waxy cuticle that reduces loss of water from the body, preventing the animal from drying out
9
Q
What are the disadvantages of exoskeletons?
A
- rigidity limits mobility
- heavy which limits growth
- animals are vulnerable while moulting
10
Q
How are the disadvantages of exoskeletons overcome?
A
- exoskeletons are shed (moulted) to allow the arthropod to grow
- arthropods have jointed limbs where the exoskeleton is thin at the joints, allows for movement
11
Q
What do endoskeletons consist of?
A
- bone and/or cartilage
12
Q
What are the advantages of an endoskeleton?
A
- supports the body, giving it shape
- made up of living tissue that can grow as the animal increases in size
- protects the internal organs
- provides anchors for muscles which work with bones to allow movement
13
Q
What are the disadvantages of an endoskeleton?
A
- not all soft tissues are protected
