Detailed yet concise lecture notes covering the content from the first lecture of invertebrate zoology. These first class notes are easy to read, understand and learn from - with helpful diagrams. Topics are covered thoroughly including:
- Bilateral and radial symmetry (with diagrams)
- Body cavi...
What is a phylum?
- A phylum unites animals with similar body plans
- DIfferent phyla show fundamentally different body plans
- Common body plans also reflect relatedness in descent
- Phyla are simply major clades - how major does a clade have to be to count as a phylum?
- What are the fundamental body plan features?
- Body symmetry: radial or bilateral?
- Number of germ layers: diploblast or triploblast?
- Type of body cavity
- Developmental fate of the blastopore: protostomes or deuterostomes
Bilateral symmetry
Bilateral symmetry in fish. Has various body axes, can be ‘cut’ in multiple ways. To produce an identical animal, the
fish can only be cut in the sagittal direction - one plane of symmetry.
Radial symmetry
Radially symmetric sea anemone. Can be
cut in various different axes, producing
identical halves of the animal.
Adaptive value
- Radial symmetry is adaptive for sessile or slow-swimming lifestyle as food and threats can come
from any direction
- Sessile animals do not move
- Bilateral symmetry is adaptive for life on the move, for animals that hunt and find food
What is the body cavity?
- A fluid filled space between the ectoderm and endoderm
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller elishakaur. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £5.49. You're not tied to anything after your purchase.