CH 25,26,32,33,34
Evolution works by _____.
"tinkering" with existing structures
Medusozoans include all cnidarians that produce a medusa:
- Scyphozoans (jellies) -Cubozoans (box jellies) -Hydrozoans
body plan of a cnidarian..
- a sac with a central digestive compartment, the gastrovascular cavity - single opening functions as both mouth and anus
Stanley Miller and Harold Urey Experiment:
-1953, first to create abiotic synthesis of organic molecule. -created inorganic materials from atmosphere to organic molecules. By lightning bolt.
Living echinoderms are divided into five clades
-Asteroidea (sea stars and sea daisies) -Ophiuroidea (brittle stars) -Echinoidea (sea urchins and sand dollars) -Crinoidea (sea lilies and feather stars) -Holothuroidea (sea cucumbers)
What catastrophic events did the volcanic eruption trigger into mass extinction?
-Atmospheric CO2 rose dramatically. -Ocean acidification reduced calcium carbonate for reef-building corals and shell-building species. -Nutrient enrichment of oceans caused microbial blooms, leading to anoxic conditions.
muscular (post anal tail)
-Chordates have a tail posterior to the anus -It provides propelling force in many aquatic species
ray finned fishes face several threats from humans, why and how?
-Fish are an important source of protein; fishing on an industrial scale has led to many fishery collapses -Damming of rivers hampers fishes' access to food, migratory pathways, and spawning grounds
Is a sixth mass extinction under way?
-Many species have become extinct and many others are threatened due to human actions to the global environment -Scientists estimate that the current rate of extinction is 100 to 1,000 times the typical background rate -Species are declining at an alarming rate due to habitat loss, introduced species, over harvesting and other factors
consequences of continental drift
-Ocean basins became deeper. -Most shallow-water habitat was destroyed. -The interior of the continent became colder and drier.
adaptive radiations can occur in response to:
-Opening of niches following mass extinctions - evolution of novel characteristics that enable the exploitation of new resources or habitats. -colonization of new regions with few or weak competitors.
What are the functions of a body cavity?
-The internal fluid cushions the suspended organs -the fluid can act like a skeleton against which the muscles of soft bodied animals can work, -the cavity enables internal organs to grow and move independently of the body wall.
sponges body is like a
-a sac perforated with pores -very simple
Living arthropods consist of three major lineages that diverged early in the phylum's evolution:
-chelicerates (sea spiders, crabs, tikes, spiders, mites, scorpions) -myriapods (centipedes and millipedes) -pancrustaceans ( insects, lobsters, shrimp, barnacles, and other crustaceans)
jawed vertebrates had diverged into 3 lineages that survive today:
-chondrichthyans -ray-finned fishes -lobe-fins
Bilaterally symmetrical animals have...
-dorsal(top) side and ventral (bottom) side -right and left side -head end and tail end
threats to freshwater and terrestrial molluscs include:
-habitat loss -pollution -competition or predation by non-native species -overharvesting by humans
List three things that occurred during the cenozoic era:
-mammals increased in size and abundance - the global climate cooled throughout this period. -the primate ancestors to humans moved into open woodlands and savannas
all mollusks have a similar body plan with 3 parts:
-muscular foot (usually used for movement) -visceral mass (containing most of the internal organs) -matle (a fold of tissue draping over the visceral mass that secretes the shell)
Hypotheses for the rise of cambrian diversity include:
-new predator-prey relationships -rise in atmospheric oxygen -the evolution of the Hox gene complex and microRNAs
All chordates share four features ________.
-notochord (below the nerve chord) -dorsal (back, hollow nerve chord) -pharyngeal slits or clefts -muscular (post-anal tail)
4 of the eight major clades of molluscs are:
-polyplacophora (chitons) -Gastropoda (snails and slugs) -Bivalvia (clams, oysters, and other bivalves) -cephaolopoda (squids, octopuses, cuttlefish, and chambered nautiluses)
Cnidarians are diploblastic with...
-radially symmetrical bodies -no terrestrial members
evolution of the exoskeleton enabled arthropods to be among the 1st animals to colonize land because...
-reduces water loos and prevents desiccation -provides structural support without the buoyancy of water
developmental genes
-regulatory genes that control genes for animal body shapes, patterns, and origins. -Played an important role during the cambrian explosion.
In response to the evolution of major innovations, several adaptive radiations occurred in response:
-rise of photosynthetic prokaryotes. -evolution of large predators in the cambrian explosion. -colonization of land by plants, insects, and tetrapods
functions of pharyngeal slits and arches:
-suspensiong feeding structures in many invertebrate chordates -modified into gills for gas exchange -tetrapods don't develop pharyngeal slits, the arches develop into parts of the ear, head, and neck
neural crest cells disperse through the embryo and give rise to many features including:
-teeth -some bones and cartilage of the skull -several types of neurons -sensory capsules
Several data sources are used to infer evolutionary relationships among the three dozen extant animal phyla:
-whole genomes -morphological traits -ribosomal RNA (rRNA) genes -hox genes -protein-coding nuclear genes -mitochondrial genes
Earth's land masses have joined into a single continent and split back apart again 3 times. When?
1 billion, 600 million, and 250 million years ago.
Neoproterozoic era
1 billion- 542 million years ago, Era in which the first animal fossils were found (Edicaran biota)
leeches range in length from...
1 to 30cm
taxonomic groups from broad to narrow
1. Domain 2. Kingdom 3. Phylum 4. Class 5. Order 6. Family 7. Genus 8. Species
Vesicles can exhibit some of the properties of life:
1. Simple growth without dilution of contents. 2. Reproduction. 3. Metabolism. 4. Maintenance of internal environment different from surroundings.
5 important points about the relationships among living animals are reflected in their phylogeny:
1. all animals share a common ancestor 2. sponges are the sister group to all other animals (basil group) 3. Eumetazoa is a clade of animals with tissues (true animals, sponges don't have tissues) 4. Most animal phyla belong to the clade Bilateria 5.there are 3 major clades of bilateral animals:- most bilaterians are invertebrates, animals that lack a backbone. - Chordata is the only phylum that also includes vertebrates, animals with a backbone.
4 stages of simple cell production
1. synthesis of small organic compounds: primordial soup, hydrothermal and alkaline vents 2. macromolecules formed by smaller organic compounds polymerizing on hot sand 3. Packaging of molecules into protocells, droplets with membranes that maintain an internal chemistry different from the environment. 4. Origin of self-replicating molecules.
haploid numbers for human is...
23
The most species in the vertebrates?
3% of all known, 1. fish, 2. birds, 3. reptiles
Prokaryotes lived on land....
3.5 billion years ago
When did earth form?
4.6 billion years ago
When did animal began to make an impact on land?
450 million years ago
Diploid numbers for human is
46
Bdelloidea rotifers have been asexual for over...
50 million years
most squid species are less than ...... but some are much larger
75CM long
shark population in the Pacific have plummeted by up to:
95%
What type of animals was also extinct during the cenozoic era?
;arge, flightless dinosaurs and marine reptiles
Which correctly describes phylogenetic relationships among birds, mammals, and reptiles? a. Birds share the closest common ancestor with dinosaurs. b. Reptiles and birds, but not mammals, are amniotes. c. Mammals evolved from therapsid reptiles after the fall of the dinosaurs. d. Birds and mammals are more closely related to each other than either group is to crocodilian reptiles.
A
Hox genes
A class of homeotic genes, provide positional information in animal embryos.
notochord
A flexible rod that supports a chordate's back
Adaptive Radiation
A rapid period of evolutionary change where many new species arise and adapt to different ecological niches.
A species of bird finds its way to the Galápagos Islands, where there are many ecological niches. This species evolves into many new species to fill all the unfilled niches. This is an example of
Adaptive Radiation
Shelled cephalopods are called
Ammonites
shared derived character
An evolutionary novelty that is unique to a particular clade.
What are the most widespread and diverse land animals?
Arthropods and tetrapods.
What were the first animals to colonize land about 450 million years ago?
Arthropods.
If you introduced the following groups of vertebrates to a newly formed island with little surface water, which would probably become dominant? a. amphibians b. reptiles c. bony fish d. coelacanths
B
Most atmospheric Oxygen is of....
Biological origin
First flying animals are?
Birds
What can fly?
Birds, insects, bats, and reptiles.
What is the largest animal?
Blue whales
Heterochrony can have significant impact on.... give example:
Body shape. Example: contrasting shapes of human and chimpanzee skulls are the result of small changes in relative growth rates of different body parts.
What are animal cells supported by?
By structural proteins such as collagen, instead of cell walls.
Archaeopteryx differed from modern birds in that it _____. a. had feathered wings b. flew well at high speeds c. could not take off from a standing position d. had airfoil wings with contoured feathers
C
Which is the closest living group to the primates? a. birds b. reptiles c. monotremes d. amphibians e. There is not enough information to decide.
C
arthropods date back to the...
Cambrian explosion
The cytoskeleton allows eukaryote cells to...
Change shape and engulf other cells.
Oxygen can attack what?
Chemical bonds, inhibiting enzymes, and damaging cells.
Which of the following most likely arose from endosymbiosis?
Chloroplasts and mitochondria.
The oldest phylum in this clade is
Cnidaria
what are an ancient phylum of eumetazoans?
Cnidarians
Hox genes control what?
Control the expression of many other genes that influence morphology.
As hominins diverged from other primates, shirk of the following appeared first? a) reduced jawbones b) an enlarges brain c) the making of stone tools d) bipedal locomotion
D
Chordates are bilaterian animals that belong to the clade of animals known as _____
Deuterostomia
Bilaterians are divided into 3 clades:
Deuterostomia, Ecdysozoa, and Lophotrochozoa
nematodes and arthropods are
Ecdysozoans
oviparous
Eggs hatch outside the mother's body (chicken, birds)
Humans are...
Eukaryotic
Which taxonomic level contains the other choices?
Eumetazoa
heterochrony
Evolutionary change in the timing or rate of an organism's development.
Phylogeny
Evolutionary history of a species or a group of related species.
Animals that possess homologous structures probably _____.
Evolved from the same ancestor.
Evolution is goal oriented. T/F
False, NOT
Rotifers are larger than many protists. T/F
False, they are smaller
Carlos Linnaeus
Father of taxonomy, and he established the system of scientific nomenclature
How many mass extinction events have been documented in the fossil record over the past 500 million years?
Five
How has life on Earth changed over time?
Fossils found in the Saharan Desert document the transition of whales from land to sea.
What fossils were found during the cambrian explosion?
Fossils of sponges, cnidarians, and molluscs appear in older rocks.
homeotic genes
Genes that determine basic features of where a body part is. (Determines where organisms feature will develop)
first part of species name:
Genus
Which is not a reason for the rise in the diversity of animal phyla during the Cambrian?
Global cooling triggered shifts in animal lineages.
Factors of rapid species decline
Habitat loss, introduced species, and over harvesting
What do heterotrophs use to grow?
Heterotrophs are organisms that grow using the carbon fixed by autotrophs.
Which of the following is the correct way to write the scientific name for humans?
Homo sapiens.
Most animals share a unique family of developmental genes called
Hox genes
What type of genes control the expression of many other genes that influence morphology?
Hox genes
The larva is sexually _______, and morphologically and behaviorally distinct from the _____ ______
Immature, adult stage
mantle cavity
In molluscs, houses the gills, anus, and excretory pores
Big four Hawaiian islands formed:
Kauai, Oahu, Maui, and Hawaii.
What did the Oxygen revolution do?
Kill everything. Drove many prokaryotic groups to extinction.
Replication and metabolism are key properties of ______.
Life
which would be a great surprise if found in the body of a sponge?
Limb
the clade bilateria contains...
Lophotrochozoa, Ecdysozoa, and Deuterostomia
Which of the following statements concerning the evolutionary origin of mammals is most likely true?
Mammalian lower jaw bones and teeth changed gradually over time.
The first coral reefs formed important ecological niches for marine animals during which era?
Mesozoic era
all eukaryotic cells have....
Mitochondria.
continental drift
Movements in the mantle cause the plates to gradually shift.
What are animals?
Multicellular, heterotrophic, eukaryotes with tissues that develop from embryonic layers.
What defines the characteristics of animals?
Nervous tissue and muscle tissues that are unique.
Are there any evidence of how life truly started?
No.
Eukaryotic cells have:
Nucleus, membrane-bound organelles, and cytoskeleton.
Know dates of cambrian explosion, ediacaran animals, diversification of dinosaurs, vertebrates, and mammals
ON PP**************
meteorites could also have been a source of ________. Give an example as well.
Organic molecules. Fragments from meteorite contain amino acids, simple sugar, lipids, and nitrogenous bases.
bilaterians
Organisms with the following traits(anything that has a left and ride side): -Bilaterally symmetric -Complete digestive tract -One way digestive system(from mouth to anus)
insects and crustaceans form the clade...
Pancrustacea
Which of the following taxonomic categories includes the fewest number of species?
Panthera
When describing a group of animals, you speak about an ancestral species and some but not all of its descendants. This is an example of a...
Paraphyletic group
The evolutionary history of a group of organisms can be represented in a branching diagram called:
Phylogenetic tree.
If the mitochondria and chloroplasts in eukaryotic cells resulted from endosymbiosis, what features might we expect these organelles to contain?
Plasma membrane, DNA, and ribosomes.
not all eukaryotic cells have..
Plastids (chloroplasts and related organelles)
traditionally, phylum annelida is divided into 3 clades:
Polychaeta, oligochaeta, and hirudinea
What are the simplest animals?
Porifera (sponges)
The changes of the rise and fall are affected by?
Processes including plate tectonics, mass extinction, and adaptive radiation.
Why do some scientists believe that RNA, rather than DNA, was the first genetic material?
RNA has both information storage and catalytic properties.
When supercontinents break apart....
Regions that were once connected become isolated.
Example of phylogeny
Shows that a legless lizards and snakes evolved from different lineages of legged lizards
Which statement about Hox genes would lose points on a test?
Simple animals such as sponges possess Hox genes.
Experiments have revealed a mechanism...
Six-legged insects could evolve from crustaceans.
Hox gene Ubx
Suppresses leg formation where it is expressed.
shelled cephalopods were once the dominant invertebrate predators of the sea. T/F
TRUE
What formed off the Mexican coast 66 million years ago?
The Chicxulub crater.
Example of tectonic plates drifting....
The Himalayan mountains formed 45 million years ago when tectonic plates collided.
What divides the Paleozoic from the Mesozoic era?
The Permian extinction (252 million years ago)
spongocoel
The central cavity of a sponge.
Plate Tectonic Theory
The earth's crust is composed of several plates floating on the underlying mantle.
serial endosymbiosis
The hypotheses that mitochondria evolved before plastids through a sequence of endosymbiotic events.
What group depends on speciation and extinction rates of its member species?
The rise and fall of any group
What do animals eat?
They ingest living or nonliving organisms.
Hox genes are thought to play an important role in the development of different morphologies because ______.
They provide positional information in the embryo.
Miller and Urey's experiments that attempted to recreate conditions on early Earth were significant because _____.
They showed that organic molecules, such as amino acids, could be produced from inorganic molecules.
The first step after sequencing DNA is....
To align comparable sequences from the study species.
Conditions on early Earth made the origin of life possible: T/F
True
Phylogenetic trees show patterns of descent, not phenotypic similarity. T/F
True
many snails are hermaphrodites. T/F
True
planarians are hermaphrodites. T/F
True
Rocks are usually dated, not the fossils. T/F
True.
Which of the following would make the most suitable outgroup species for a cladogram relative to all the other species?
Tuna
In water, lipids and other organic molecules can spontaneously form ______.
Vesicles with a lipid bilayer.
the first organic compounds may have formed in reducing conditions near the openings of ________.
Volcanoes.
Major changes in climate occur when.... Give example:
When a continent shifts toward or away from the equator. Example: Labrador, Canada, was located in the tropics 200 million years ago.
Ediacaran biota
Where animals fossils were first discovered.
viviparous
Young develop within the uterus and are nourished by a yolk sac placenta, absorption of nutrient-rich fluid, or by eating other eggs (most stressful, and most energy requiring)
Which correctly describes phylogenetic relationships among birds, mammals, and reptiles? a. Birds share the closest common ancestor with dinosaurs. b. Reptiles and birds, but not mammals, are amniotes. c. Mammals evolved from therapsid reptiles after the fall of the dinosaurs. d. Birds and mammals are more closely related to each other than either group is to crocodilian reptiles. e. Among living species in the group we call reptiles, turtles and snakes are most closely related to each other.
a
Hemocoel (pseudocoelom)
a body cavity formed between the mesoderm and endoderm
Coelom
a body cavity surrounded by tissues derived from mesoderm
shared ancestral character
a character that originated in an ancestor of the taxon
Systematics
a discipline focused on classifying organisms and determining their evolutionary relationships
Most triploblastic animals have a body cavity...
a fluid or air filled space between digestive tract and the outer body wall (testable on LAB as well)
Tissues are....
a group of similar cells that act as a functional unit.
The gastrovascular cavity acts as....
a hydrostatic skeleton
Phylogenetic tree represents:
a hypothesis about evolutionary relationships
basal taxon
a lineage that diverges early in the history of a group
tapeworms do NOT have
a mouth or gastrovascular cavity
Slugs squids, and octopuses have?
a reduced internal shell
evolutionary lineage
a sequence of ancestral organisms leading to a particular descendant taxon
Bilateral animals typically move...
actively and have a central nervous system
Bivalves have a shell divided into two halves drawn together by:
adductor muscles
what are sea squirts?
adult tunicates
If you discovered a fossil that fit between the crocodilians and pterosaurs, what feature would it probably have?
amniote eggs
A clade is a group of species that includes...
an ancestral species and all of its descendants
All members of Ecdysozoa secrete...
an external skeleton (exoskeleton)
-zoa/zoo-
animal
Which is not true of the Neoproterozoic era?
animal diversity decreased
molluscs have the largest number of documented extinctions among...
animals
downside for clams:
anything that they clean/eat like toxins, they store it within themselves.
bivalves are all...
aquatic and include many species of clams, oysters, mussels, and scallops.
Most modern chelicerates are .......?
arachnids
Two orders of wingless insects
archaeognatha and zygentoma
tissues
are collections of specialized cells that act as a functional unit
Ameobocytes
are totipotent cells within the mesohyl that digest food, transport nutrients, and make skeletal fibers
What was the first to adapt to life on land and influenced plants?
arthropods
if you wanted to show an example of segmentation to a group of visiting students, which phylum would be the best choice?
arthropods
A confused friend from your course has made a Halloween costume that is supposed to show one animal phylum. It has a hard outer shell and a water vascular system. You point out that the costume combines features of _____.
arthropods and echinodermata
Vertebrates are chordates that have a ______
backbone
most animal species are bilaterians which have...
bilateral symmetry and triploblastic development
Most of the fossils from the Cambrian explosion are of:
bilaterians
two-part scientific name of a species:
binomial
A number of characters distinguish humans from other apes: 1. Upright posture and ____ locomotion 2. Larger brains capable of language, symbolic thought, artistic expression, and the manufacture and use of complex tools 3. Reduced ____ and jaw muscles 4. Shorter ___ ____
bipedal, jawbones, digestive tract
Cleavage leads to formation of a _______, often in the form of a hollow ball of cells. The ______ will undergo ______, forming a _________ with different layers of embryonic tissues.
blastula, gastrulation, gastrula.
Animal can be characterized by....
body and plans
In animals with radial symmetry, what's arranged?
body parts are arranged around a single central axis.
Animal diversity can be described by a few major _____ _____, set of morphological and developmental traits.
body plans
segments united to form _______
body region
Animals can be compared based on ___________.
body symmetry, or lack of it (many sponges lack symmetry, which makes them asymmetrical)
in cubozoans, the medusa stage is...
box-shaped
the surface area of structures is maximized by..
branding, flattening, folding, and projections
the first letter of the genus is ______, and the entire species name is _______.
capitalized, italicized.
skeletal system and complex nervous system have allowed vertebrates efficiency at two essential tasks:
capturing food, and evading predators
centipedes are
carnivores
No animals have..
cell walls.
Which era followed mass extinctions of both terrestrial and marine animals?
cenozoic era
the nervous system for planarians is ...
centralized and more complex than that of cnidarians
Major changes in body form can result from...
changes in the sequences and regulation of developmental genes
ancestral
characters shared by the outgroup and ingroup
arachnids have six paired appendages:
chelicerae, pedipalps, and four pair of walking legs
sponges have several different cell types:
choanocytes and amoebocytes
What are the closest living relatives to animals?
choanoflagellates, a group of protists
If these animal phyla had a cocktail party, which one would feel most unwelcome?
chordata (because they are vertebrates)
______ are ______ animals belonging to the clade called deuterostomia.
chordates , bilaterian
cyclostomes
clade of living jawless vertebrates
How can we make sense of the great number and morphological diversity of invertebrates?
classifying invertebrate species into groups based on evolutionary relationships helps us to understand their great diversity.
Animal zygotes undergo
cleavage
the nervous system is centralized and more complex than that of..
cnidarians
tentacles are armed with...
cnidocytes
lobefin diversity dwindled during the Devonian period with only 3 lineages surviving today:
coelacanths (cold fish water), lungfishes (fish that can breathe in and out of water), tetrapods
most bilaterians have a...
coelom and a digestive tract with two openings (mouth and anus)
each branch point represents the divergence of two evolutionary lineages from a ....
common ancestor.
cladistics organisms are grouped primarily by...
common ancestry.
cloaca
common chamber with a single opening to the outside of the body (birds, salamander)
Some body plans are _______, while others have changed many times over the course of evolution.
conserved
Unrelated species evolve similar traits through....
convergent evolution in response to natural selection to similar environmental conditions.
Ectoderm
covers the embryos surface, and gives rise to the outer covering and central nervous system
nematodes (roundworms) have ...
cylindrical Bodies tapered at the ends and covered by a cuticle
What should animals with radial symmetry be better able to do than those with bilateral symmetry?
dear effectively with food distributed homogeneously in all directions.
Living vertebrates have shared...
derived characters, where it distinguishes them from other chordated
if the protostome or deuterostome cells ever separate/split, they ____
die
The rise and fall of groups of organisms reflect....
differences in speciation and extinction rates
closely related species are likely to?
different at only one or a few sites along the DNA sequence.
Distantly related species usually have...
different bases at many sites and may have different lengths.
The dominant stage in animals is
diploid
a polyphyletic group includes...
distantly related species but does not include their most recent common ancestor
statistical tools are used to....
distinguish between distant homologies and coincidental matches.
Cnidarians includes what animals?
diverse sessile and motile forms including corals, hydras, and jellies (jellyfish) or (sea jellies)
errantia is a large and....
diverse, mostly marine, clade -mostly have well developed jaws as well
Mammals underwent an adaptive radiation and they....
diversified and filled the ecological niches left open following the mass extinction.
chordates have a notochord and a _____
dorsal, hollow nerve cord
Tectonic plates can....
drift apart, collide (forming mountains), or slide past each other (causing earthquakes)
indeterminate cleavage
each cell produced by early cleavage is able to form a complete embryo
hermaphrodites
each individual functions as both male and female
what are the most species wish animal group?
ecdysozoans
Which phylum has a water vascular system?
echinoderms
ovoviviparous
eggs that hatch within the body (hatch internally) (snakes)
examples of macroevolution:
emergence of terrestrial vertebrates(in ocean), impact of mass extinctions, origin of key adaptations (such as flight in birds)
Birds are _____, capable of maintaining body temperature through metabolism
endothermic
based off of analysis, annelids are NOW divided into 2 clades:
errantia and sedentaria
sedentarians tend to be less mobile than..
errantians
All animals except sponges are ...
eumetazoans, animals with true tissues
Metizones
everything that is in an animal
Reptiles can be defined as ectothermic (cold blood) amniotes (egg laying) T/F
false, because Non-avian reptiles can be defined as ectothermic and amniotes
animals have a cranium, fur, and mammary glands. T/F
false, because mammals have a cranium, fur, and mammary glands
body region is specialized for...
feeding, walking or swimming
Mesoderm (middle)
fills the space between ectoderm and endoderm, and gives rise to muscles and most organs.
Bivalves are what kind of feeders?
filter feeders
conodonts
first vertebrates with mineralized skeletal elements in their mouth and pharynx
Choanocytes
flagellated collar cells, engulf bacteria and food particles by phagocytosis
phylum platyhelminthes (flatworms) includes
flatworms that live in marine, freshwater, and damp terrestrial habitats
lophotrochozoans are a diverse group composed of 18 phyla including:
flatworms, rotifers and acanthocephalans, ectoprocts, brachiopods, mollusks and annelids
insect radiations followed periods of diversification in their...
food plants
What several features do birds and crocodiles share?
four-chambered hearts, song, nest building, and brooding.
A medusa is a ...
free swimming form that has a bell-shaped body with the mouth on the underside.
what groups are the most severely threatened?
freshwater bivalves and terrestrial gastropods
lineages with shorter branches reflect fewer ......
genetic changes than those with longer branches.
other characters common to gnathostomes include:
genome duplication, enlarged forebrain, smell and vision, lateral line system
australopiths were more slender and had lighter jaws
gracile
pharyngeal slits or clefts
grooves in the pharynx that develop into slits that open to the outside of the body
Taxon
group or level of organization into which organisms are classified
sister taxa
groups that share an immediate common ancestor that is not shared by any other group
what are the only living vertebrates that lack jaws and backbones?
hagfishes and lampreys
Mammals are amniotes that have
hair and produce milk
The history of animals spans more than...
half a billion years
Triploblastic animals
have three germ layers during development - ectoderm, mesoderm, and endoderm
Diploblastic animals (cnidarians)
have two germ layers that give rise to the tissues and organs of the embryo.
bivalves have no distinct ___ _____ or ____
head or radula
ancestral chordates likely had genes associated with vertebrate organs including the...
heart and thyroid
deuterostomia includes ...
hemichordates (acorn worms), echinoderms (sea stars and relatives), and chordates (including vertebrates)
Most sponges are
hermaphrodites
The distribution of fossils and living groups reflect on the.... Give Example:
historic movement of continents. Example: fossils of the same species of Permian reptiles are found in Brazil and West Africa.
extinct species that are more closely related to humans than to chimpanzees
hominins
When constructing a phylogeny, systematists need to distinguish whether a similarity is the result of ......
homology or analogy.
Phylogenetic trees can be drawn....
horizontally, vertically, or diagonally without changing the relationships between groups
The study of ___ ____ is known as paleoanthropology
human origins
tapeworms are parasites of mostly vertebrates including...
humans
radula
in molluscs, they feed using a straplike (radula) to scrape up food
earthworms are valued for their role to be...
in tilling, aerating, and improving the texture of agricultural soils.
rooted tree
includes a branch to represent the last most recent common ancestor of all taxa in the tree
In which type of cleavage pattern does each cell have the capacity to develop into a complete embryo ?
indeterminate cleavage
What animal group has more species?
insects
any imaginary slice through the central axis divides the animal....
into mirror images
some leeches are predators of ...
invertebrates
members of deuterostomia may be ...
invertebrates or vertebrates
What does a filter feeder do?
it captures particles suspended in the water that passes through its body.
which statement misdescribes the lateral line system?
it is used in digestion
gnathostomes
jawed vertebrates, including sharks, ray finned fishes, lobe finned fishes, amphibians, reptiles (including birds) and mammals
lampreys are
jawless fish
hagfishes are
jawless, with reduced vertebrae and cartilaginous skull
trophi
jaws
the oceans most efficient swimmer is a....
jellyfish
earthworms are hermaphrodites that cross-fertilize by...
joining in opposite directions to exchange sperm
many nematodes live freely in moist soils and at the bottoms of the ....
lakes and oceans
which chordate group has all four key chordate characteristics as an adult, not just as an embryo?
lancelets
vertebrates have 2 or more sets of hot genes, but:
lancelets and tunicates have only one
arthropods were the first animals out on...
land
some leeches live on...
land
Humans are mammals that have a
large brain and bipedal locomotion
3 main group of living primates
lemurs, tarsiers, and anthropoids
The diapsids are composed of two main lineages1. The ____ include tuataras, lizards, snakes, and extinct mososaurs2. The _____ lineage produced the turtles, crocodilians, pterosaurs, and dinosaurs
lepidosaurs, archosaur
annelids have a coelom (no hemocoel) and range from...
less than 1 mm to more than 3m in length
Tetrapods are gnathostomes that have
limbs
Sponges are sessile, meaning that they:
live attached to a solid structure and do not move around.
clams clean the water that they...
live in
Crustaceans (crabs, lobsters, barnacles, shrimps)
live in marine freshwater
Tetrapods evolved from ....
lobe-finned fishes around 365 million years ago
Decapods are all relatively large crustaceans and include
lobsters, crabs crayfish, and shrimp
advantage of hermaphrodite
low mobility
Major boundaries between eras correspond to....
major extinction events in the fossil record
Mammals have many derived characters: 1. ___ glands, which produce milk 2. Hair and a fat layer under the skin for ____ 3. ____, which conserve water from wastes 4. Endothermy and a high metabolic rate 5. Efficient respiratory and circulatory systems 6. A large brain-to-body-size ratio 7. Extensive parental care 8. Differentiated ___
mammals, insulation, kidneys, teeth
sharks have a streamlined body and are swift swimmers, but do not...
maneuver well
bivalves gills are housed inside the...
mantle cavity and are used for suspension feeding and gas exchange
Cambrian explosion
many present-day animal phyla appear suddenly in fossils formed in the Cambrian period.
all 30 species of hagfishes are..
marine
most mollusks are..
marine
Lancelets
marine suspension feeders, named for their blade like shape
annelids are segmented worms that live in...
marines, freshwater, and damp soil habitats.
The Cambrian Explosion
marks a period of rapid animal diversification.
Unlike plants and fungi, sperm and egg cells are produced directly by...
meiotic division in animals.
Mammals appeared during which era?
mesozoic era
Myriapoda includes ___ and centipedes
millipedes
most rays are bottom-dwellers that use crushing jaws to feed on:
molluscs and crustaceans
Ediacaran fossils
molluscs, sponges, or cnidarians.
small group of egg-laying mammals consisting of echidnas and the platypus
monotremes
By the early Cretaceous, the three living lineages of mammals emerged:
monotremes (egg laying animals), marsupials(mammals with a pouch), and eutherians(placenta mammals)
tunicates
more closely related to other chordates than are lancelets
Phylogenies are inferred from..
morphological and molecular data
Systematists use data on the......
morphology, genes, and biochemistry of organisms to infer phylogeny.
Which statement about arthropods would lose points on an exam
most arthropod sensory organs are concentrated at the posterior end
which trait is shared by all vertebrates except cyclostomes at some point in development?
mouth with jaws (cyclostomes do not have jaws)
Animals are...
multicellular eukaryotes
if you discovered a new organism with 10 jointed legs, you would expect it to have _______.
muscles attached to an exoskeleton (arthropods)
what is the first chordate to have a head?
myllokunmingia
what are the largest ecdysozoan phyla?
nematodes and arthropods.
dorsal (hollow nerve chord)
nerve cord found in all chordates that forms the spinal cord and brain
protonephridia
networks of tubules with ciliated structures called flame bulbs that pull fluid through branched ducts opening to the outside
"Flat-nosed" Prehensile tails 12 premolars Most dichromatic vision Most are small & arboreal No opposable thumb Most form pair bonds Substantial parental care(monkeys)
new-world
tunicates have fewer hot genes...
nine instead of 13
can all groupings of organisms be qualified as clades?
no
adult hagfish have the
notochord as a flexible rod of cartilage
The first monkeys evolved in the ___ (Africa and Asia). In the New World (_____ _____), monkeys first appeared roughly 25 million years ago
old world, south america
Most animals have at least ______
one larval stage
Heterotrophic
organisms that must have their food in an organic way. They rely on other organisms as well in order to eat.
phylum Nematoda include spirals is a ...
parasite that can be acquired by humans by eating undercooked pork
many flatworms are...
parasites such as flukes and tapeworms
homologies
phenotypic and genetic similarities due to shared ancestry
shared characters are used to construct....
phylogenetic trees
Fossil data is used to...
place branch points in the context of geological time.
insertions and deletions are...
point mutations that shift the entire DNA sequence following the mutation.
coral reefs are being destroyed rapidly by...
pollution, over harvesting, and ocean acidification
The size and diversity of mammals was restricted by:
predation and competition from dinosaurs.
During the mesozoic era, dinosaurs emerged as...
predators and herbivores.
fossils of haikouella are the most..
primitive
Many animals can be categorized as having one of two developmental modes:
protostome development or deuterostome development
Genes that program development control the...
rate, timing, and spatial pattern of change in an organism's form as it develops.
The ___ clade includes the tuataras, lizards, snakes, turtles, crocodilians, birds, and some extinct groups
reptile
Which group soon outcompeted amphibians on land due to their watertight skin and eggs?
reptiles
planarians are...
rhabditophorans that live in fresh water and prey on smaller or feed on dead animals
determinate cleavage
rigidly determines the developmental fate of each embryonic cell very early.
australopiths (known as _____) had sturdy skulls and powerful jaws
robust
Anthozoans, which occur only as polyps, include....
sea anemones and corals
the major difference between the two divisions of annelids, the errantians and sedentarians, is that ________.
sedentarians are less mobile than errantians.
**the arthropod body plan consists of a...
segmented body, hard exoskeleton, jointed appendages
cephalopods have a well developed...
sense organs, and a complex brain
pedipalps function in
sensing, feeding defense, or reproduction
lateral line system
sensitive receptor system that enables fish to detect gentle currents and vibrations in the water
Adult tunicates are
sessile
radially symmetrical animals are often...
sessile or planktonic (drifting or weakly swimming)
most sharks are carnivores that have _______ for tearing flesh
several rows of sharp teeth
most mollusks have separate .......
sexes
canthodians
shark-like that have jaws
What can do oviparous, ovoviviparous, and viviparous?
sharks
Chondrichthyans
sharks and rays
benefit of sexual reproduction?
shuffle of genes. it is important because if the environment changes, the offspring genes may not be successful.
Many spiders produce __________, that are used to trap small arthropods on which they feed.
silk
Lobe fins arose in the
silurian period
Analogy is....
similarity due to convergent evolution
Homology is....
similarity due to shared ancestry.
lancelets swim using a
simplified form of the mechanism used by fishes
spicules are part of the
skeleton
microRNAS
small RNAs involved in gene regulation
Oldest fossils of multicellular eukaryotes are....
small red algae from about 1.2 billion years ago
Adaptive radiations can be limited to.... give example:
small regions if a few organisms colonize isolated environments with little competition. Example: the "silversword alliance" descended from an ancestral tarweed.
phylum Mollusca includes...
snails and slugs, oysters and cams, and octopuses and squids
earthworms eat through...
soil, extracting nutrients, and eliminating indigested material as fecal castings.
Corals can be...
solitary or colonial, form symbioses with algae, and secrete a hard exoskeleton (external skeleton) of calcium carbonate
Nematocysts
specialized organelles within cnidocytes that eject a stinging thread.
Many animals with protostome development have:
spiral and determinant cleavage
Sharks have a short digestive tract with a ridge called the ___ to increase digestive surface area
spiral valve
What other groups lack tissues?
sponges and a few others
book lungs
stacks of folded wall-like structures
A scolex at the anterior end of a tapeworm contains...
suckers and hooks in order to attach to a host
what's the largest fish?
sunfish
Larger organisms have proportionally less..
surface area over which exchange processes can occur
the flat body of a flatworm increases...
surface area, placing all cells close to water, either in the surroundings or the gut
Which osteichthyan structure allows bony fishes to control their buoyancy using gases from their blood?
swim bladder
an air sac called the ____ is filled to maintain buoyancy
swim bladder
Mammals belong to a group of amniotes called
synapsids
what have a single hole behind the eye socket on each side of the skull for attachment of the jaw muscle
synapsids
cnidarians are predators that use...
tentacles to capture and consume and prey.
phylogenetic bracketing predicts....
that features shared by two closely related groups will be present in their ancestor and all its descendants.
What are the 2 groups of early land vertebrates survive today?
the amphibians and the amniotes.
Macroevolution
the broad pattern of evolution above the species level (Species above level.)
systematics attempts to understand....
the diversity and relationships of living and extinct organisms. They use it to understand and reconstruct phylogeny.
classification
the division of organisms into increasingly broad taxonomic categories.
Mammals underwent an adaptive radiation after....
the extinction of terrestrial dinosaurs
Paleozoic era
the first large animal fossils with hard skeletons date back to this time.
In animals with bilateral symmetry, body parts are arranged around 2 axes of orientation:
the head-tail axis and dorsal-ventral axis
Endoderm
the innermost layer, lines the blind ouch (archenteron) that will form the gut, and gives rise to the lining of the digestive tract and organs.
isopods are
the largest groups of crustaceans
the body consists of two layers of cells separated by
the mesohyl
Animal body plans also vary according to...
the organization of the animal's tissues
Key events in life's history include..
the origins of unicellular and multicellular organisms and the colonization of land
Each in-group species is compared with...
the outgroup to differentiate between shared derived and shared ancestral characters.
spiral cleavage
the planes of cell division are diagonal to the vertical axis of the embryo
radial cleavage
the planes of division are either parallel or perpendicular to the embryos vertical axis
Taxonomy
the scientific discipline concerned with classifying and naming organisms.
There are two variations on the body plan of a cnidarian
the sessile polyp and motile medusa
polyps adhere to
the substrate by the aboral end of the body (the end opposite the mouth)
The porifera lineage aren't the same as other animals because...
their cells are not organized into tissues
ancestors to birds
theropods
millipedes have many legs, but fewer than a ...
thousand
rotifers are
tiny animals that inhabit fresh water, the ocean, and damp soil. They are one of the main groups of zooplankton.
Sponges are basal animals that lack...
tissues
sensory structures throughout the body allows cnidarians....
to detect and respond to stimuli
Two important groups of parasitic rhabditophorans..
trematodes and the tapeworms
Some triploblastic animals do no have a body cavity (acoelomatee). T/F
true
ecdysozoans are animals with a cuticle and a touch external coat. T/F
true
Eu- means
true, normal, good, does not include sponges since they do not have tissues
cnidocytes
unique cells used in defense and prey capture
neural crest
unique to vertebrates, appears along the edges of the closing neural tube
Proglottids (Tapeworm)
units that contain sex organs and form a ribbon behind the scolex
chordates compromise all vertebrates and two groups of invertebrates:
urochordates and cephalochordates
open circulatory system
uses a heart to pump hemolymph into the cavity surrounding the tissues and organs
acanthocephalans are sexually reproducing parasites of...
vertebrates
there are more than 60,000 species of _______, animals with a backbone
vertebrates
many crustaceans have highly specialized appendages such as:
walking legs are located on the thorax
arthropod appendages have become modified for...
walking, feeding, sensory reception, reproduction, and defense
what is the largest shark?
whale shark
lophotrochozoans, a clade identified by molecular data, have the...
widest range of animal body forms
Cephalopods are the only molluscs __________.
with a closed circulatory system
Are humans deitrostomia?
yes
Do many animals have a hemocoel and a coelom?
yes
Were vertebrates late to get on land?
yes
