3.2 Exploring Animal DIversity Flashcards
members of this kingdom are…
Eukaryotic
Lack cell walls
Multicellular
Heterotrophs
Motile (at some point)
Form a hollow ball of cells, called a blastula, during embryological development
35 different phyla
blastula
a hollow ball of cells formed during embryological development
evolution of animals
Similar to plants in terms of movement from water onto land
bodyplan of animals
-Unique to each species
- “Blueprint”
-body symmetry, body cavity, head,
embryological development, segmentation,
limbs, etc.
asymmetrical
No distinctive shape
-no symmetry
E.g. Sea Sponges, phylum Porifera
Radial symmetry
-Cylindrical, body parts arranged around central axis
-Lack a head and have no real front or back end
-Interactions with env. from any direction; useful if sessile(can’t move)
-E.g. Sea Anemone, phylum Cnidaria
Bilateral Symmetry
-Mirror image right and left sides
-Most common; well adapted for movement
-Cephalization: development of head with sensory organs
-ex. phylum arthropod
cephalization
development of head with sensory organs
segmentation (repeating parts)
-Earthworms, aka annelids (“little rings”)
-Contain repeating segments that are all very similar except for a distinct head and tail
-Some segments may become specialized to perform certain functions
Limbs (flippers, legs, wings)
Bilaterally symmetrical animals often have paired limbs or other external appendages
(e.g. gills, wings, antennae, fins, arms, etc.)
These limbs may be used for many purposes
(e.g. movement or defense)
zygote
diploid
forms when sperm fertilizes an egg
blastula
-a hollow ball of dividing cells
-Infolding forms a tube from one end to the other
-Forms the digestive tract (mouth OR anus)
what forms the digestive tract
blastula
blastopore
the first opening of digestive tract
If Mouth = protostome
(protos = first, stoma = mouth)
If Anus = deuterostome
protostome
mouth formed first
deuterostome
anus formed first
What sequence of development do biologists use to determine how closely species of animals are related?
blastopores and whether they’re protostomes or deuterostomes
examples of protostomes
molluscs, arthropods, annelids
examples of deuterstomes
echinoderms, chordates
chordates vs. vertebrates
not all chordates are vertebrates
-(they don’t all have a backbone)
all vertebrates are chordates
-(they have a notochord, which all chordates have)
what is animal evolution traced through
Animal evolution is traced through comparative anatomy, embryology, genetics, and molecular studies
order of groups in vertebrate phylogeny
Sponges
Cnidarians
Flatworms
Rotifers
Molluscs
Annelids
Roundworms
Arthropods
Echinoderms
Chordates
vertebrates
have a backbone
invertebrates
DO NOT have a backbone
Comprise more that 98% of all animals!
examples of invertebrates
porifera (sponges)
cnidaria (jellyfish, anemones)
platyhelminthes (flatworms)
nematoda (roundworms)
annelids (segmented worms)
mollusca (snails, squids, clams)
arthropods (insects, crustaceans, spiders)
echinodermata (sea stars, sea urchins, sea cucumbers)
vertebrate examples
hagfishes
lampreys
sharks and ray
ray-finned fish
lobe-finned fish
lung fishes
amphibia(frog, salamanders)
mammals
turtles
lizards, snakes
crocodiles, alligators
aves (birds)
vertebrates
Make up most of the phylum chordata
-fish, amphibians, reptiles, birds, mammals, and
humans
Skull and backbone are 2 unique features:
-protect main parts of nervous system
-vertebrae enclose nerve cord
-skull protects brain
evolution of vertebrates
-Hagfishes and Lampreys are the most closely related to the common ancestor of all vertebrates
-ALL vertebrates other than Hagfishes and Lampreys have hinged jaws
-The evolution of the hinged jaw in sharks and rays enabled vertebrates to capture and eat a wide variety of prey
-The development of paired limbs in these fish also aided in catching prey and locomotion
give examples of further evolutionary developments which allowed vertebrates to survive and reproduce on land
lungs/derivatives, legs, and amniotic eggs
what is the definition of an animal?
an animal is an organism that has/follows all these characteristics:
Eukaryotic
Lack cell walls
Multicellular
Heterotrophs
Motile (at some point)
Form a hollow ball of cells, called a blastula, during embryological development
what distinguishes an animal from animal-like protists?
Protists are unicellular organisms, whereas animals are multicellular organisms.
what is the significance of the blastula during embryological development?
develops into a digestive tract, whether it’s mouth first or anus first determines if you’re a protostome or deuterostome
give one example of a vertebrate without hinged jaws, and one example of a vertebrate with hinged jaws
w/o = hagfish, lampreys
with= turtles, alligators
what characteristics are unique to vertebrate animals?
-skull
-backbone
what advantage does cephalization give bilaterally symmetrical animals?
The cephalization/bilateral symmetry combination allowed animals to have sensory organs facing the direction of movement, allowing a more focused assessment of the environment into which they are moving.
explain the evolutionary significance of the amniotic egg
waterproof egg with a shell, allowed vertebrates to reproduce on land
describe how embryonic development can indicate the evolutionary relationships between different invertebrates
depending on if their mouth or anus formed first, making them a protostome or deuterstome, is what biologists use to determine how closely related species of animals are
suppose you are a zoologist working in a labratory. An animal you are observing has the following characteristics: bilateral symmetry, open circulatory system, mantle cavity and a complete digestive tract. In which phylum does this animal belong?
molluscs
compare and contrast the process of digestion in flatworms, roundworms, and annelids
flatworms- digestive sac
roundworms- complete digestive tract with 2 openings + has stomach and intestines
annelids- complete digestive tract with 2 openings + has stomach and intestines
describe how tetrapods may have evolved from fish-like ancestors
Limbs and lungs evolved in certain fishes that scientists hypothesize included the ancestors of terrestrial vertebrates.
Leg-like limbs may have allowed these animals to paddle and crawl through the dense vegetation and could support their weight as they moved onto land
feathers
modified scales that may have evolved as insulation to conserve heat
the backbone of vertebrates is composed of a series of skeletal segments called ____, which enclose the nerve cord
vertebrae
