Ch 30-32 (exam 2) Flashcards
characteristics of animals
- multicellular
- life cycles are patterns of development
- heterotrophs
- use internal processes to break down food
- can move
morphological synapomorphies
many organisms have similar extracellular molecules and types of junctions between cells
body plan
the general structure, arrangement of organ systems, and integrated functioning of its parts
4 key features that can be similar in body plan
- symmetry
- structure of body cavity
- segmentation of the body
- external appendages that move the body
Spherical symmetry
– body parts radiate out from a central point (unicellular protists)
Radial symmetry
one main axis around which body parts are arranged (ctenphores and cnidarians)
Bilateral symmetry
can be divided into mirror images by a single plane
Acoelomate
- lack an inclosed, fluid filled body cavity
- Space between gut and muscular body wall filled with cells called mesenchyme
- Typically move by beating cilia (flatworms)
Pseudocoelomate
- fluid filled space in which many of the internal organs are suspended
- Pseudoceol is enclosed by muscles on its outside, no inner layer of mesoderm
- surrounding organs (roundworms)
Coelomate
– have a body cavity that develops within the mesoderm
- Lined with a layer of muscular tissue called peritoneum
- Coelom is enclosed on both the inside and outside by mesoderm (earthworms)
Segmentation improves
control of movement
- Facilitates specialization of different body regions
- Allows animals to alter shape of body
- Can control movements precisely
Appendages enhance
locomotion:
Obtain food, avoid predators, find mates,
find suitable habitats
animals that move are
motile
animals that don’t move are
sessile
types of feeding strategies
- filter feeding to capture small orgs
- herbivores
- predators
- parasites
- detritivores
filter feeding
- use a strainer
- can rely on water current
- sponges bring in water by beating flagella of choanocytes
Herbivores
- usually eat one plant and don’t kill it
- expend energy digesting and have long guts
Predators
- capture prey
- have sharp sensors or toxins
Parasites
- live in or on something else
- have to overcome host defences
endoparasite
live in hosrt
ectoparasite
live outside hosrt
life cycle
embryonic development, birth, growth to maturity, reproduction, and death
Larva
an immature life cycle that has a form different from that of the adults
Metamorphosis
radical changes in life cycles (butterflies, beetles, flies)
dispersal stage
animals moves so that it does not die where it was born
trade-off
No life cycle can maximize all benefits – the characteristics of an animal in one life cycle may improve its performance in one activity but reduce its performance in another
Parasite life cycles
- evolved to facilitate dispersal and overcome host defenses
- Energy cost to obtain food may be low but cost of overcoming host defenses may be high
- Must disperse to new hosts (if host dies, they die)
Phyla Porifera
sponges
- no symmetry
- spicules
- beat choanocytes to filter feed
- asexual and sexual
Phyla Cnidaria
- hydrozoans, jellyfishes, sea anemones, corals
- have a gastrovascular cavity that functions in digestion, circulation, gas exchange
life cycle of cnidaria
polyp, sessile and reproduce by budding,
medusa is the jellyfish.
- planula will settle on the bottom and develop into a polyp
(See a picture)
medusa structure
- Floats with mouth and feeding tentacles turned downward
- Produce egg and sperm and release them to the water
- Fertilized egg develops into free-swimming larva called planula
- planula settles and turns into a polyp
class Scyphozoa
in cnidaria jellyfish, sea jellies
- medusa dom
- male or female medusa
- polyp will grow, Budd off other polyps and release medusae
class hydrozoa
in cnidaria hydras, hydroids
- polyp dom and colonial
- single large gives rise to a colony of polyps sharing one gastrovascular cavity
- can have nematocysts to catch food, defend colony
class anothozoa
sea anemones, coral
anemones
- sessile
- have nematocysts covered in tentacles
corals
- sessile and colonial
- polyps form a skeleton that deposit calcium carbonate
- endosymbiotic
gastrulation
During early development and hollow ball indents in embryo
blastopore
The opening of the cavity
Protostomes
mouth arises from blastopore
- bilaterally symmetrical
- anterior brain that surrounds the entrance to the digestive tract
- ventral nervous system consisting of paired or fused nerve chords
Deuterostomes
blastopore becomes anus
protostome clades
Arthropods, Mollusks, Lophotrochozoans and the Ecdysozoans
arthropod modification of body cavity
ost the enclosed body vessels and instead have a hemocoel “blood chamber” -
mollusks modification of body cavity
also have open circulatory system but retain connective tissue around major organs
Endoderm
will be a lot of inner lining, blood vessels, organs and systems:
mesoderm
bones, muscles etc.
ectoderm
skin
Lophotrochozoans (Protostomes)
- internal skeleton
- use cilia to move
- have a lophophore and are mostly sessile
- many are like worms, bilaterally symmetrical and legless
Ecdysozoans (Protostomes)
- have an exoskeleton that they molt made of chitin
- some have think flexible skeleton called cuticle
- had to evolve gases if hard shell but cuticle works
lophopore (Protostomes)
ridge around the mouth that has ciliated hollow
tentacles
in lophotrochozoans
lophotrocozoans flatworms (Protostomes)
flatworms, rotifers, ribbon worms
- no gas exchange organ
- have chemoreceptor eye spots
- move by cillia
- parasitic
lophotrocozoans annelids (Protostomes)
- segmented
- have a coelom
- have a nerve centre called a ganglion
- have a body that does gas exchange
- restricted to moist
lophotrocozoans mollusks (Protostomes)
- foot: used for locomotion and support
- visceral mass: all the organs
- mantle secretes the shell
mollusca clade (Protostomes)
chitons, bivalves, gastropods, cephalopods
`chitons (Protostomes)
- multiple gills and shell plates
- Bi symmetry
- moves slow by foot
bivalves (Protostomes)
`- clams, oysters etc
- hinged
- use foot to burrow
- bring in water through incurrent siphon
gastropods (Protostomes)
- snails, limpets etc
- move by gliding on foot
- live on land
- mantle can be modified into lung
cephalopods (Protostomes)
- squids, octopi etc,
- excurrent siphon is modified to move
- capture with tentacles
- have eyes
Ecdysozoans (Protostomes)
tardigrade
why are arthropods successful (Protostomes)
- segmented
- joint appendages
- exoskeleton
- waterproofing
4 groups of arthropods (Protostomes)
Crustaceans – shrimpls, crabs, barnacles
Hexapods – insects
Myriapods – millipedes and
centipedes
Chelicerates – arachnids (spiders, scorpians, mites)
crustaceans (Protostomes)
- head, thorax, abdomen
- head can be fused
- each segment has a set of appendages
- appendages are specialized for gas exchange, chewing, sensing etc.
carapace (Protostomes)
(extension of exoskeleton) may extend back from head to cover head and thorax in crustaceans
insects (Protostomes)
- three regions
- have tracheae to breathe that open from spiracles
- antenna
– Johnston’s organ (Protostomes)
Insects can be distinguished from other hexapods by external mouthparts and
paired antennae that contain a sensory organ
deuterstomes categories
echinoderms, hemichordates, chordates
chordate clades
Urochordates, Cephalocordates, Vertebrates
all chordates have
A dorsal hollow nerve cord
A tail that extends beyond the anus
A dorsal supporting rod called the notochord
notochord
- large cells with fluid-filled vacuoles
- in urochodates, this is lost to adult
- in vertebrates, it is a skeletal structure
pharynx
develops aroundd slits
like lungs
vertebrates
have a jointed, dorsal vertebral column that replaces the notochord
- internal skeleton
- large brain with an ab anterior skull
- coelom
- developed circulatory system
new features in the chordates
jawless fish, jawed fish, teeth, fins and swim bladders
jawless fish
hagfish and lampreys
jawed fish
evolved through the gills
teeth
breaks up prey and helps get nutrients
fins
help stabilize and move through water
pectoral fins
behind gills
pelvic fins
anterior to anal region
swim bladders
- depth control
Chondrichthyans
- sharks, rays
- skeleton of cartelige
- live on ocean floor
Ray finned fishes:
- have calcified bone structures
- covered with scales
- gills covered by an operculum that help push water over them
how did vertebrates move to land
lung sacs and joined fins helped to breathe and walk
lungfishes have joined fins
amphibians
- Caecilians, Anurans, Urodela
- First Tetrapods on land!
- must be moist
- lay eggs in water
amniotes
- live terrestrially
amniote egg
- impermeable to water
- protected but still gas exchange
- stores food as yolk
- extra-embryonic membranes protect embryo from drying out
mammals
- sweat
- mammary glands
- haor
- 4 chambered heart
- in body fertilization
mammal groups
protherians and therians
protherians
duck-billed platypus, echidnas
- lack a placenta
- have sprawling legs
- supply milk for young
therians
two groups are marsupials and eutherians
marsupials
- females have ventral pouch
- gestation is brief
- cannot fly
eutherians
- have a placenta
- young are developed at birth
- have teeth
eutherian categories
prosimians/ wet-nosed primates
anthropoids/ dry-nose primates
prosimians/ wet-nosed primates
lemurs
- only found in afraid, madagascar
- live in trees
anthropoids/ dry-nose primates
- old and new world monkeys
new world monkeys
- long tailed live in trees
old world monkey
live in trees, no tail
what characterize the primates
- bipedal locomotion
homo erectus
- made fire
- 1.6 million years ago
homo sapiens
200,000 years ago
- jaw size decrease
- communicate
