chapters 25 and 26 Flashcards
Give the 6 traits that identify organisms as animals.
- multicellular 2. eukaryotic 3. heterotrophic 4. no cell walls 5. usually motile 6. usually ingests food
Give the 4 survival needs of animals
- maintain homeostasis 2. obtaining and circulating nutrients 3. collecting and excreting wastes 4. gathering and responding to information
animals with backbones
vertebrates
animals without backbones
invertebrates
the phylum of organisms that includes vertebrates, have two cords running down their back at some point in their lives
chordates
Give the four major traits of chordates.
- notochord 2. dorsal, hollow nerve cord 3. pharyngeal slits/pouches 4. post-anal tail
What does the notochord become in humans and other vertebrates?
structural support, backbone (spine) or vertebrae
What does the nerve cord become?
spinal cord and brain
What do the pharyngeal slits and pouches become in humans?
part of the ear and throat
What do the pharyngeal slits and pouches become in fish?
gills
a fertilized egg
zygote
the early cell divisions, divide into progressively smaller, identical cells called blastomeres
cleavage
the identical cells within a blastula, created by cleavage
blastomeres
the solid ball of cells created by cleavage
morula
the hollow ball of cells created by cleavage
blastula
the stage in embryonic development created by the invagination (bending in) of the blastula
gastrula
the opening into the gastrula
blastopore
What two possible things does the blastopore become?
mouth or anus
having no symmetry
asymmetry
having circular symmetry like spokes on a wheel where body parts extend outward from a center point
radial symmetry
having one plane of symmetry with two mirror halves
bilateral symmetry
Which type of symmetry is best in more active animals?
bilateral
Which type of symmetry is best in sessile animals or ones that don’t move much?
radial
5-part radial symmetry common in echinoderms
pentaradial
Name and describe the location of the 3 embryonic germ layers.
endoderm - inner layer ectoderm - outer layer mesoderm - middle layer
What do each of the 3 embryonic germ layers become?
endoderm - lining of digestive and respiratory tracts ectoderm - skin and nervous system mesoderm - muscle, bone and connective tissues
a true body cavity (space lined with mesoderm)
coelom
a fake body cavity (space not lined with mesoderm)
pseudocoelom
no body cavity
acoelomate
What are 2 functions of body cavities?
- room for organs to move 2. room for food storage…
What are animals called if the blastopore becomes their mouths, and what does it mean?
protostomes - mouth first
What are animals called if the blastopore becomes their anus, and what does it mean?
deuterostomes - mouth second
What animals are protostomes?
all invertebrates except echinoderms
What animals are deuterostomes?
all vertebrates plus echinoderms
What term means the development of a head end?
cephalization
What is the advantage of having a head?
sense organs are concentrated - head enters environment first and can sense danger
What is the advantage of segmentation?
animals could grow larger without adding more DNA - just repeated
What happened with segmentation to make it even more advanced?
segments fused and became specialized
What are appendages?
anything sticking off the body like legs, antennae, mouthparts…
What group of animals is composed of basically specialized cells and no tisses?
poriferans - sponges
What group of animals is made of only two germ layers so no organs?
cnidarians - corals, anemones, jellies
What is the term for having two germ layers?
diploblastic
What is the term for having three germ layers?
triploblastic
What is the advantage of having a third germ layer?
can build organs
What group of animals is asymmetrical?
sponges
What two groups of animals have radial symmetry?
cnidarians and echinoderms
What is unusual about echinoderm larvae?
bilateral symmetry and a head
a diagram that shows the evolutionary relationships between groups of organisms
cladogram
What do nodes on a cladogram represent?
when traits show up
What do branches on a cladogram represent?
when groups of organisms diverge from one another
the process by which an animal takes in oxygen and releases carbon dioxide
breathing
the process by which an organism releases wastes from its body
excretion
the process by which an organism distributes materials around its body
circulation
cells without a nucleus - the only example
prokaryotes - bacteria
cells with a nucleus - give examples
eukaryotes - protists, fungi, plant, animal
reproduction by combining two haploid gametes
sexual
What does the word haploid mean?
having half the DNA
the process by which an organism breaks down food to a usable form
digestion
the geologic time period when most major forms of life first appear in the fossil record
Cambrian Explosion
the sponges
Poriferans
the jellyfish, corals and anemones
Cnidarians
the jointed foot animals like insects, spiders, centipedes, millipedes…
Arthropods
the roundworms like hook worms and pin worms
Nematodes
the flatworms like a tapeworm or planarians
Platyhelminthes
the segmented worms like earthworms and leeches
Annelids
the spiny skinned animals like sea stars, sand dollars, sea urchins…
Echinoderms
the soft bodied animals with shells like snails,clams, octopus, and squid
Mollusks
a water skeleton
hydrostatic
a rigid skeletal material reinforced with collagen and calcium
bone
a more soft, flexible skeletal material
cartilage
a complex cell with a nucleus and membrane-bound organelles
eukaryote
an organism that must eat other organisms to survive, a consumer
heterotroph
If a student looks at cells under a microscope, how might the student know it is NOT an animal cell?
has cell walls
95% of all animals are what? Less than 5% of all animals are what?
95% invertebrates 5% vertebrates
a stable internal environment in organisms
homeostasis
Why do animals eat?
to get nutrients and energy
What is the advantage of sexual reproduction?
produces diversity to allow organisms to adapt to a changing environment and new living conditions
What body system works closely with the muscles to allow movement?
skeletal
How does muscle tissue work to allow movement?
contracts or shortens to pull on bones
What is the difference between an endoskeleton and an exoskeleton?
endo - inside and grows with you exo - outside and must be molted
A vertebrate has which type of skeleton, endoskeleton or exoskeleton?
endo
What is a possible advantage of asexual reproduction?
increase numbers rapidly
To maintain homeostasis, an animal that hunts and feeds in salt water needs adaptations to do what?
get rid of excess salt to maintain homeostasis
What is the most simple method for obtaining oxygen?
diffusion through skin
How would you describe an organism with this body plan?
acoelomate
In an animal that is bilaterally symmetrical, what two sides mirror each other?
left and right
a true coelom is lined with what tissue?
mesoderm
What is the difference between a protostome and a deuterostome?
when and where the mouth forms
What develops from ectoderm?
skin and nerves
What develops from endoderm?
digestive and respiratory tract
What develops from mesoderm
muscle, bone, blood
What type of symmetry do jellyfish have?
radial symmetry
Why do animals without 3 germ layers not have organs?
Mesoderm allows for muscle and connective tissue to build organs.
What is the advantage of an endoskeleton?
It grows with the animal and doesn’t need to be molted.
On what continent do we believe humans evolved?
Africa
Why do echinoderm larva have bilteral symmetry?
Echinoderms have a bilateral ancestor. Bilateral symmetry allows the larvae to move to new locations before becoming adults.
Why are starfish and their relatives considered more closely related to chordates than other invertebrates?
They are deuterostomes.
seeing with two eyes at the same time, gives depth perception
binocular vision - allows them to go from branch to branch without falling
walking upright on two legs, frees the hands for using tools
bipedalism
a grasping tail in monkeys
prehensile
grasping thumb, works opposite fingers
opposable
grasping thumb, works opposite fingers
Homo sapien
the order of mammals including monkeys, apes, and humans
primates
the great apes
hominoids
human-like primates (monkeys, apes, and humans)
anthropoids
human lineage, modern humans and extinct ancestors
hominenes
the largest unit of time on the geologic time scale
eon
the entire history of life on earth divided into units of time
geologic time scale
the time period meaning recent animals, dominated by mammals
cenozoic
the time period meaning middle animals, dominated by reptiles including dinosaurs
mosozoic
the time period meaning ancient animals, dominated by invertebrates, fish, and amphibians
paleozoic
the time period when ancestors of all the major phyla appeared for the first time
Cambrian explosion
the major time period when life first formed in the oceans, originally thought there was no life
Precambrian
What is the advantage of a true coelom?
can eat a larger meal and have muscle to churn and push food along
What is the advantage of bilateral symmetry?
have a definite head and can be more active
What is the advantage of radial symmetry? What type of lifestyle do animals with radial symmetry share?
Name the 2 groups of animals with radial symmetry.
good when food comes at you from many directions and you can’t move to get it
- echinoderms
- cnidarians
a major group of related organisms
phylum (phyla)
a flexible material that forms the skeleton of some organisms
cartilage
the shedding of skin or exoskeleton
molting
vertebrates with fins and scales
fish
vertebrates with dry, scaly skin and leathery shelled eggs
reptiles
vertebrates with moist skin and eggs without shells
amphibians
vertebrates with wings and feathers
birds
endothermic animals with fur, feed babies milk
mammals
