Test 1 Flashcards
List the 4 major environments
Marine, Estuaries, Freshwater, Terrestrial
In which environment did life originate?
Marine
Where is most animal life found today?
Marine
Estuaries are ____ ____ coastal, interaction of ____ and ____ environments, brackish, ____ influence, and ____ rich.
low lying, fresh, marine, tidal, nutrient
Running freshwater is known as ____.
lotic
Standing freshwater is known as _____.
lentic
Body size of freshwater fluctuates due to these 4 reasons.
temperature, dissolved gasses, pH, and salinity
Terrestrial environments are most _____ due to ____ ____ and ____.
severe, temperature extremes, moisture
Respiration: aquatic vs. terrestrial
- internal/external gills, body surface
- lungs, tracheal system (internalization)
Excretion: terrestrial vs. aquatic (What do they excrete?)
- urea
- ammonia
Fertilization: aquatic vs. terrestrial
external
internal
Development: terrestrial vs. aquatic
often internal, can be external
external
Characteristics of animals (8)
lack of cell wall, multicellular eukaryotes, membrane bound organelles, heterotrophic, motility, diploid, specialization of cells, most capable of locomotion at some point in life
Define invertebrate
an animal without a backbone
What does protozoa mean?
the very first animals
Why are animals referred to as metazoans?
the animals that came after the first animals
What are protozoa invertebrates?
Some consider them unicellular invertebrates but they are not true animals.
Define taxonomy
a branch of systematics that deals with naming, describing, and classifying organisms
Define systematics
the study of diversity and evolutionary relationships
To determine evolutionary relationship we depend on (3)
fossils, similarities in body plan, and patterns of development
The earliest known animal fossils are called _____.
Ediacaran
The relatively sudden appearance of most of the existing phyla of animals has been named the ____ ____.
Cambrian Explosion
Define classification
assigning organisms into groups based on similarities
What is the goal of systematics?
to reconstruct phylogeny
Define phylogeny
the evolutionary history of a group of organisms from a common ancestor.
Define symmetry
arrangement of body structures in relation to the body axis
In radial symmetry, many planes can be drawn through the _____ axis; each divides the animal into ___ ___ images.
central, two mirror
_____ is the concentration of nervous and sensory tissues and organs at one end of an animal; evolved with bilateral symmetry.
Cephalization
_____ and _____ are closely related because they share radial symmetry. Most other animals show bilateral symmetry.
Cnidarians and ctenophores
In cephalization, the head of the animal is its ____ end, and the opposite end is its ___ end. The animal has _____ and _____ halves that are mirror images of each other.
anterior, posterior, right/left
A diploblasitc has only the _____ and _____ germ layers.
ectoderm and endoderm
A triploblastic has ____, _____, and ____. Most of the invertebrate phyla are classified here.
ectoderm, endoderm, and mesoderm
The ectoderm is the ____ layer. What is its function?
outer, to give rise to the body covering, nervous system
The _____ is the inner layer. It lines the gut and other digestive organs.
endoderm
The middle layer is called the ____. What is its function?
mesoderm, it gives rise to most other body structures
Acoelomate = ____ body cavity. An example of this are _____.
no, flatworms
______ = a body cavity not completely lined with mesoderm. An example of this would be _____.
Pseudocoelomate, roundworms
An animal with a true body coelom is known as a _____. Examples of this include ____, ____, ____, and ____.
coelomate; molluscs, annelids, arthropods, and beagles
A ____ is a fluid filled space between the body wall and the digestive tube.
coelum
Protostomes form their _____ before their ____; which is why they are also known as “_____ ____.”
mouths, anus, first mouth
_____ form their anus before they form their mouths. Therefore, they are called “ _____ _____.”
Deuterostomes, second mouth
Examples of protostomes include ____, ____, and ____.
molluscs, annelids, arthopods
An example of a deuterostome is a ____.
human
A _____ is an opening from the embryonic gut to the outside.
blastopore
In protostomes, the blastopore usually develops into the _____.
mouth
In _____, the blastopore may become the anus and the mouth will form somewhere else.
deuterostomes
Protostomes undergo _____ cleavage while deuterostomes undergo _____ cleavage.
spiral, radial
Deuterostomes have early cell divisions either _____ or at ___ ____ to the polar axis while protostomes have early cell divisions _____ to the polar axis.
parallel, right angles, diagonal
In deuterostomes, cells lie _____________________.
directly above or below one another
Protostomes undergo ______ cleavage while deuterostomes undergo ______ cleavage.
determinate, indeterminate
In _____ cleavage, the fate of each embryonic cell is fixed very early.
determinate
In _____ cleavage, the fate of each embryonic cells is more flexible.
indeterminate
_______ _______ confirmed much of the animal phylogeny based on structure and developmental characteristics.
Molecular systematics
Molecular systematics tell us that not all animal body plans evolved from ____ to _____.
simple, complex
Molecular Systematics cant do three things. What are they?
reveal exact steps as one group gave arise to another, tell selective pressures that caused changes, and tell us what ancestral animals looked like.
Lophotrochoza are ____/____ animals.
crest/wheel
Ecdysozoa are animals _____ _____.
that molt
The _____ is a ciliated organ around the mouth used for collecting food and gas exchange.
lophophore
_____ _____ allow biologist with different languages to communicate about organisms.
Scientific names
_____ _____ came up with the hierarchical system of classification in 1758.
Carolus Linnaeus
What is the order of classification that Carolus came up with?
Domain Kingdom Phylum Class Order Family Genus Species
Members of a species share a ____ ____.
gene pool
Each species name has two parts. What are they?
Genus name and specific epithet
Species: Psilotreata rossi Wallace, 1970 and Psilotreata indecisa (Walker, 1852)
Why is Walker in () and Wallace not? What are the years for?
Walker’s species has been moved to a different genus since he named it. When they named it.
_____ insist that taxa be monophyletic.
Cladistics
_____ are shared derived characters.
Synapomorphies
Cladistics use _______ to determine relationships.
Synapomophies
____ consists of a common ancestor and all its descendants.
Clades
_____ are used to show which taxa shared a common ancestor and how recently they shared it.
Cladograms
Nodes show ___________
divergence of groups from a common ancestor.
The most recent common ancestor of each _____ _____ is found at the node.
monophyletic group
________ ___________ determines which characters in a given group of taxa are ancestral and which are derived.
Outgroup analysis
_____ are taxon that represents ancestral condition. They diverged earlier than other taxa investigated.
Outgroups
What is monophyletic?
1 phyla
Which is considered to be good: monophyletic, paraphyletic, or polyphyletic?
Polyphyletic
In searching for the origins of animal life, what lines of evidence have been used?
fossils
What systems/abilities do sponges lack? (6)
muscles, limbs, brain, definitive shapes, movement (for the most part), and a nervous system
What abilities do sponges have? (5)
cologen, sucking in water and filtering out food particles, “hearts,” central cavity, and sperm/eggs
What materials are used to give sponges their rigidity and form?
Spicules and cologen
How old are the ancient sponge fossils found in China?
550 million years old
What evidence has been used to conclude that sponges are at the base of the animal tree?
Fossils and genetic sequences
The Poriferan classification incudes 4 classes. What are they?
Calcarea, Demospongiae, Hexactinellida, Homoscleromorpha
Class Calcarea have skeletons of _____ ________.
calcium carbonate
Class Demospongiae have skeletons of _______ _____, _____, and/or _____.
spongin protein, chitin, silica
Class Hexactinellida have skeletons of ____ and _____.
silica and chitin
Class Homoscleromorpha mostly lack ____ but, if present, are made of _____.
spicules, silica
In what way are cindarians more complex than sponges? What characteristics did they add? (7)
movement, sensitive tentacles, predatory, mouth, muscles, stomach, and nerves
What do these additions allow cnidarians to do?
capture food, digestion, compete
Name and describe the two different versions of the cnidarian body plan.
Medusa - bell shaped
Stalk like with trailing tails
What are nematocysts? What do they do?
explosive cells found on the tail of jelly fish, capture and kill prey
If the pulsing of a jellyfish isn’t only for locomotion, what else does it do?
help capture prey
How do animals without brains perform and control their activities?
nerve network - receive and respond to stimuli
What kind of skeleton does an anemone have, and how does it work? How is it different from the human skeleton?
Hydrostatic
Movements - circular, long
Put together, push against water to move
Human - skeletal frame, muscles pull to move
______ sponges filter water to feed so, they are thought to be good indicators of pollution.
Freshwater
______ contain cells from which new sponges grow. This is a type of _____ reproduction.
Gemmules, asexual
Most sponges are _________. This means there is not a distinct male and female.
hermaohrodites
Some sponges are ________ to form sperm, others eggs but, these are usually made at different times so they cross-fertilize with other sponges.
archaeocytes
Where does fertilization and early development of a sponge take place?
mesohyl
Bacteria sometimes make up __% of a sponges volume.
40
What are microbes doing for sponges?
Some microbes house blue-green algae which probably provides sugar to the sponge. Some microbes may help defend the sponges from disease causing bacteria.
What are sponges doing for microbes?
Some sponges pass on microbes, like blue green algae, to offspring via sperm and eggs.
One species of Phylum _____ has been described?
Placozoa.
Placozoans are structurally _____ but genetically ____.
simple, complex
Where are plazoans placed on the phylogenetic tree?
between the sponges and cnidarians
Cnidarians are characterized by: (5)
radial symmetry, two tissue layers, tentacles around mouth, one opening for digestive system, cnidoblasts
What is a cidoblast?
a cell containing nematocysts
What is a cnidocyte?
a fully developed cnidoblast
What are the two body shapes of cnidarians?
polyp form and medusa form
The polyp form of cnidarians have a ____ body, ____ mouth, and are usually _____.
tubular, dorsal, stationary
The medusa form of cnidarians look like an _____ ____, they have a ____ mouth which means it is on the lower surface, and they usually _____.
upside-down cup, ventral, swim
Cnidarians are _____, meaning they have two definite tissue layers.
diploblastic
Amoebocytes are found in the ______. They are in things like _____, _____ and ____ _____, and ____ ____.
mesoglea, digestion, storing, moving nutrients, repairing wounds
____ were the first active predators.
Cnidarians
Cnidarians have two types of “muscle” cells. What are they? Why are they not true muscle cells?
epithelia and nutritive muscle, they are not from the mesoderm
Nutritive muscle can ____ ____ and are anchored in the ____.
capture food, mesoglea
Cnidarians get their name from specialized cells called _______. These contain stinging organelles called ____.
cnidoblasts, cnidae
What stimuli can trigger cnidoblasts? Modified cilia on the tigger, called _____, receive these stimuli.
chemical and physical, cnidocil
______ _______ is the force that causes a nematocyst to shoot a coiled, hollow thread to kill/capture prey.
Osmotic pressure
Class _____ are known as “true jellyfish.”
Scyphozoa
Class Hydrozoa are considered to be _____ ____.
“other” jellyfish
Corals and sea anemones fall in to Class _____, while sea wasps fall into Class ______.
Anthozoa, Cubozoa
There are around _____ species in Phylum Cnidaria.
11,000
____% of all cnidarians are anthozoans and _____% are marine.
70, 99.8
Two additional Classes to Phylum Cnidaria are ______and _____.
Myxozoa & Staurozoa
Class Myxozoa has been added to Phylum Cnidaria fairly recently. This class has _____ species of parasites (mostly fish).
~2,000
Class Scyphozoa (true jellyfish) has _____ species and ____ % are marine, usually in _____ water.
a few hundred, 100, coastal
_____ is the dominate body form of Class Scyphozoa and Cubozoa.
Medusa
Class Cubozoa is known as the _____ jellyfish because it is ____ shaped.
box, square
Molecular data indicates that Class _____ is probably the most advanced of all cnidarians.
Cubozoa
Class Hydrozoa is mostly ____ but has some ____ species.
marine, freshwater
Most species of Class _____ alternate between the polyp and medusa stages but some species have only one or the other. The ____ form is most often the dominate stage.
Hydrozoa, polyp
There are _______ species of Class Hydrozoa.
less than 3,000
Class Anthozoa has no _____ stage and they are all _____.
medusa, marine
In Class Anthozoa, the ____ form produces the eggs and sperm. A fertilized egg develops into a ______ which attaches to form a new polyp.
polyp, planula
In Class Anthozoa, ______ _____ divide the g-v cavity which increases surface area for digestion.
vertical partitions
