Lecture 18- Animals Flashcards
What makes an animal an animal?
- heterotrophs
- no cell walls
- multicellular
- cells organized into tissues
- movement
Most animal species posses a _____ stage
larval
Larva definition
sexually immature form of an animal
Larva characteristics
- morphologically distinct from adult
- eats different food
- sometimes different habitat
animal genes involved in adherence and attachment have sequence similarities in
Choanoflagellates
First macroscopic fossils of animals came from the
Neoproterozoic era
Bilaterians are a
clade whose members have a bilaterally symmetric form and complete digestive tract
Bilaterians came around during the
Cambrian explosion
As the diversity of animal phyla increased during the cambrians period, the diversity of ____ declined
Ediacaran life forms
Why did edicaran life forms decline during the Cambrian explosion
- adaptations for predation and defense, Edicaran life forms were selected against
- new phyla adapted to higher oxygen levels and have higher metabolic rates with larger body sizes
Animals can be characterized by body plans:
- body symmetry
- developmental mode
- tissues
- body cavities
Types of body symmetry
- no symmetry
- Radial symmetry
- Bilateral symmetry
What can be inferred by radial symmetry
meets environment equally from all sides so not very mobile
what can be inferred from bilateral symmetry?
CNS located in the head which is important for complex movements (moves a lot)
Blastopore definition
develops into digestive tract opening
ectoderm definition
gives rise to outer cover of animal
Endoderm definition
lining of digestive tract and other organs
Diploblast have ___ layers and consist of animals such as ____
2, jellyfish and corals
What layers do diploblast and triploblast both have?
endoderm and ectoderm
Triploblasts make up all ____- animals
bilaterally symmetrical
What layer does the triploblast have that the diploblast doesn’t have?
mesoderm
What does the mesoderm form?
muscles and other organs
Body cavity definition
fluid or air filled space between digestive tract and outer body wall
Coelom definition
surrounded on all sides from tissue made from mesoderm
