the simplest, single-celled eukaryotes, but they still carry out life functions and show division of labour among the various cell structures
2 of 34
What is a metazoan?
multicellular animals that have cells specialised for particular functions
3 of 34
What is bilateral symmetry?
symmetrical arrangement of an organism or part of an organism along a central axis, so that the organism or part can be divided into two equal halves. a characteristic of animals that are capable of moving freely through their environment
4 of 34
Bilateral symmetry is associated with cephalisation. What is this?
the differentiation of a head
5 of 34
Why was the evolution of a body cavity important?
Isolation of organs for physiological independence - kidney function different from liver. Flexibility when moving- organs don’t rip apart.Prevents organs from sticking to each other - cells like to intermingle
6 of 34
When is the gut formed?
during gastrulation
7 of 34
what are Pseudocoel/coelom?
fluid filled body cavities that cushion organs and provide support
8 of 34
The body plan and its cavities are made of 3 ‘germ layers’. what are they?
Endoderm Mesoderm Ectoderm
9 of 34
What are acoelomates?
organisms with no body cavity (e.g. jellyfish)
10 of 34
what are Pseudocoelomates?
organisms which have a body cavity between mesoderm and endoderm (e.g. round worm)
11 of 34
What is the body cavity in Pseudocoelomates called?
Pseudocoel
12 of 34
What are Coelomates?
have a body cavity entirely within the mesoderm (e.g. arthropods)
Comments
No comments have yet been made