Midterm 2 Guide - Animal Diversity Flashcards
1
Q
Cambrian explosion
A
- occurred approx. 550mya
- no. of special “exploded”
- bilateralism not established at once but many key traits of modern animal phyla first seen
2
Q
key traits of animal
A
- *multicellularity (no cell walls, extensive extracellular matrix)
- heterotrophy
- motility
- nerve & muscle cells
3
Q
cephalization
A
- concentration of nervous system components at one end of the body
- point of symmetry down center
- allows forward movement & predation
4
Q
types of sensory receptors
A
- chemoreceptors
- mechanoreceptors
- photoreceptors
5
Q
chemoreceptors
A
- detect oxygen, carbon dioxide, glucose, amino acids
- basis for smell and taste
6
Q
mechanoreceptors
A
- respond to touch, stretch, pressure, motion, sound
- motion & gravity (hair cells)
- sound
- echolocation
7
Q
photoreceptors
A
-detect light (vision)
8
Q
3 types of eyes
A
-eye cups, compound eyes, single-lens eyes
9
Q
types of feeding
A
-suspension/filter feeding, deposit feeding, suction feeding
10
Q
Porifera characteristics
A
- sessile
- filter feeders
- asymmetric
- no tissue layers
- asexual and sexual reproduction
- have choanocytes (flagellated cells)
11
Q
sponge reproduction
A
- asexual (piece breaks off and forms new colony)
- sexual (mass of sperm & eggs released to be fertilized)
12
Q
Where on the phylogenetic tree did tissue evolve?
A
-developed after multicellularity (but Porifera branch off without tissues)
13
Q
Cnidirian characteristics
A
- diploblasts
- radial symmetry
- have cnidocytes
- asexual and sexual reproduction
14
Q
Cniadrian reproduction
A
- asexual (budding, fission, fragmentation)
- sexual (broadcast spawning, gametes) (like sponges)
15
Q
cnidocytes
A
- cells containing nematocysts
- nematocysts are harpoon-like (stingers), respond to touch.movement
