Exam 3 Flashcards
1
Q
When did the division between protostomes and deuterostomes occur?
A
670 MYA
2
Q
Which animals are on the deuterostome phylogeny, but doesn’t share the common ancestor of chordates?
A
echinodermata
3
Q
What makes echinoderms unique?
A
They are the only non-chordate group in the deuterostome phylogeny.
They are the only invertebrate deuterostomes.
4
Q
What are the only invertebrate deuterostomes?
A
Echinoderms
5
Q
Do echinoderms have bilateral symmetry?
A
Yes, as larvae.
6
Q
List the traits ALL chordates have.
A
Notochord
Dorsal, hollow nerve chord
Muscular, post-anal tail
Pharyngeal clefts and slits
7
Q
Describe a notochord. Where is it?
A
flexible, longitudinal rod between digestive tract and dorsal, hollow nerve chord
present in all chordate embryos, some adults
8
Q
What kind of tissue is the notochord derived from?
A
mesoderm
9
Q
What is the notochord’s function?
A
to provide skeletal support
10
Q
What does the dorsal, hollow nerve chord develop into?
A
central nervous system
11
Q
What does the central nervous system derive from?
A
dorsal hollow nerve chord
12
Q
What tissue is the dorsal hollow nerve chord derived from?
A
ectoderm
13
Q
Where is the dorsal hollow nerve chord in relation to the notochord?
A
interior
14
Q
Why is the muscular, post-anal tail unique to chordates? What do non-chordates have instead?
A
In non-chordates, the digestive tract spans the body length.
15
Q
Where are pharyngeal clefts and slits?
A
below the mouth
16
Q
Describe pharyngeal clefts and slits.
A
arches along pharynx develop into slits that open into pharynx
17
Q
What function do pharyngeal clefts and slits serve in invertebrates?
A
suspension feeding
18
Q
What do pharyngeal clefts and slits become in aquatic vertebrates?
A
gills
19
Q
What do pharyngeal clefts and slits become in terrestrial vertebrates?
A
The slits no longer exist. They are integrated into the ears, head, and neck.
20
Q
- If ALL chordates have a notochord, then this trait isI. a synapomorphyII. a polytomyIII. homologousIV. analogous
- I and II
- I and III
- II nad III
- II and IV
A
b. I and III
21
Q
What are the two basal chordates?
A
Lancelets and Tunicates
22
Q
Which basal chordate has the notochord protecting the dorsal hollow nerve chord? Why is it necessary?
A
Lancelets. Because they lack additional skeletal support.
23
Q
How do lancelets eat?
A
They filter feed using pharyngeal slits.
24
Q
Which basal group of chordates has larvae that reflect chordate characters, but adults that lose those characters after metamorphosis?
A
Tunicates
25
What do tunicates use siphons for?
filter feeding and waste removal
26
List the characteristics of vertebrates.
Vertebrae
| Developed nervous system
27
What are the two kinds of vertebrae?
cartilaginous or bony
28
What do vertebrae do?
Provide protection of nervous systems and skeletal support
29
Describe the nervous system of vertebrates.
Cranium protects the brain and spinal chords are present.
30
What are the basal vertebrates?
Hagfish and Lamprey
31
List the three characteristics hagfish and lampreys have in common.
Jawless without a backbone.
Rudimentary vertebrae (no spine).
Notochord persisting in adults (provides skeletal support because of absent spine)
32
Which vertebrate has reduced sensory structures, tubes with organs inside, and produce slime as a defense?
hagfish
33
Describe hagfish.
Basal vertebrate
- Reduced sensory structures
- Tubes with organs inside
- Produce slime as a defense
- Jawless, no backbone
- Rudimentary vertebrae (no spine)
- Notochord persists in adults (skeletal support because spine is absent)
34
Which basal vertebrates parasitize fish?
lampreys
35
Describe lampreys.
- cartilaginous teeth (not mineralized) lack collagen
- adults parasitize fish
- basal vertebrates
- Jawless, no backbone
- Rudimentary vertebrae (no spine)
- Notochord persists in adults (skeletal support because spine is absent)
36
When did vertebrate-transitional fossils appear?
530 MYA (during the Cambrian explosion)
37
When did the earliest vertebrates appear?
500 MYA
38
Did mineralization start before or after vertebrates appeared?
after
39
Where did mineralization start in the body?
with teeth-like structures
40
When did the earliest gnathosomes appear?
440 MYA
41
What are gnathosomes?
vertebrates with jaws and mineralized skeletons
42
What prompted rapid radiation in fish?
the appearance of jaws
43
What is the leading, but unproven, hypothesis for jaws' evolution?
Jaws originated from skeletal rods that support gill slits. They marked a reduction in the number of pharyngeal slits and a change in the function of gills from feeding to respiration.
44
What is the evidence that suggests the current leading hypothesis for jaw evolution? What is missing?
- Jaws and rods have similar morphology.
- Both derived from the same cells in the embryo (unlike other skeletal elements)
However, there is no fossil evidence.
45
- Why did jaws lead to an adaptive radiation in fishes?
1. They increased the diet breadth of animals
2. They represented the origin of predation in chordates
3. They can increase the attractiveness of male fish, leading to increased female mate
choice.
4. All of the above
They increased the diet breadth of animals
46
Describe sharks.
- Cartilaginous skeleton
- Mineralized teeth
- Vertebrate
- Streamlined body for hunting
- Nearly continuous swimming
47
What is different about the largest sharks?
They are filter feeders, not hunters.
48
What are some of sharks' adaptations for predation?
sharp vision
olfactory bulbs
detection of electric fields of other animals
49
Why do sharks continuously swim?
- To keep from sinking. There's a lack adaptations to keep them afloat.
- To put oxygen across gills to facilitate gas exchange
50
Describe ray-finned fish.
Bony fish with rays in fins.
- Possess gills for gas exchange
- Swim bladder maintains buoyancy
- Lateral line that detects pressure and vibrations
51
What did the swim bladder in ray fins derive from?
Lungs appeared first and were adapted into the swim bladder.
52
What are the two kinds of lobe-finned fish?
Coelocanths and Lungfish
53
What is unique about coelocanths?
They have bones in their fins that resemble wrists. They were thought extinct, but found alive in 1938.
54
Describe lungfish.
- Breathe air and have gills
- Fleshy fins, can walk short distances under water
- Closest living relative to tetrapods
55
Which animal is the closest living relative of tetrapods?
Lungfish
56
- Which of the following statements about chordates is/are true?
1. All chordates have a notochord as embryos.
2. All chrdates are mobile as adults.
3. All chordates have pharyngeal slits as embryos that develop into essential traits as adults.
4. All of the above
a. All chordates have a notochord as embryos.
57
- Which of the following statements about vertebrates is/are true?
1. Fossil evidence suggests that the direct ancestors of vertebrates evolved during the Cambrian explosion.
2. Vertebrates
all have spinal cords.
3. Not all vertebrates have mineralized bones because mineralization is a derived trait of bony fish.
4. All of the above
1. Fossil evidence suggests that the direct ancestors of vertebrates evolved during the Cambrian explosion.
58
What are the three groups of animals with limbs of digits?
Amphibia are sister taxa to Reptilia and Mammalia
59
Which characteristic of deuterostomes evolved first?
notochord
60
Why are Tiktaalik important and what do they help us understand?
An intermediary that helps us understand transition from lungfishes to tetrapods (with limbs).
61
Why couldn't Tiktaalik live on land?
Spine and pelvis were not fused.
62
When did tetrapods first appear in the fossil record?
365 MYA
63
What adaptations did vertebrates need to succeed on land?
- New way to move (instead of swimming)
- Increased skeletal support to deal with gravity
- New gas exchange method to replace gills
- Strategies to prevent water loss
64
What are the 4 derived traits of tetrapods?
- limbs with digits
- head separated from body via neck
- bones of pelvic girdle fused to backbone
- adults lack gills (exceptions)
65
What function does having the pelvic girdle bones fused together with backbone serve?
provides additional support to deal with gravity
66
What is one derived trait of tetrapods with exceptions?
Adults lack gills.
67
Describe amphibians.
- Land-dwelling tetrapods
- Aquatic larvae (with some exceptions)
- Moist skin to facilitate gas exchange
- External fertilization in water or moist environments
- Live part of lives in water, rest in land
68
How does external fertilization work in amphibians?
Sperm and eggs meet outside the body in water or moist environments.
69
Why do amphibian eggs lack shells?
important for gas exchange
70
Amphibians are particularly sensitive to climate change, which is contributing to current species declines. Why?
1. Permeable skin and permeable eggs make amphibians sensitive to changes in temperature.
2. Increased
CO2 in the atmosphere makes it harder for amphibian larvae to obtain oxygen through
their lungs.
3. Living in the water and on land makes amphibians poorly adapted to change.
4. All of the above
Permeable skin and permeable eggs make amphibians sensitive to changes in temperature.
71
Describe salamanders.
Amphibians
- Can be aquatic, partially terrestrial, or fully terrestrial
- Some capable of limb regeneration
- Some lack lungs (terrestrial species)
- Large amount of diversity in Appalachians.
72
What are plathadons?
terrestrial salamanders that lack lungs
73
How do plathadons do gas exchange?
Through their skin (they lack lungs).
74
Describe frogs.
Amphibians
- Aquatic larvae distinct from terrestrial adults
- Hop instead of walk
- Males vocalize to attract mates or defend territory
- Some produce deadly toxins advertised with bright colors.
75
What separates reptiles and mammals from amphibians?
amniotic egg
76
What is amnion?
fluid filled cavity of amniotic egg that surrounds and protects the embryo by providing insulation
77
What insulates the embryo in amniotic egg?
amnion
78
What is the yolk sac?
place where mother provides nutrients in the amniotic egg during the developmental stage
79
What is the allantois?
part of amniotic egg that holds metabolic waste during development
80
What function does the chorion serve?
serves as site for gas exchange (cellular respiration) in the amniotic egg
81
What is the fluid filled cavity protecting the embryo in the amniotic egg?
amnion
82
Where do mothers provide nutrients during the developmental stage of amniotic eggs?
yolk sac
83
What holds metabolic waste in the amniotic egg during development?
allantois
84
What functions for gas exchange in the amniotic egg?
chorion
85
What are the three derived traits of amniotes?
- Eggs with shells or internal gestation
- Less permeable skin
- Rib cage used for ventilation
86
How does the presence of shells in amniotes help?
reduces water loss of developing embryo
87
How does having less permeable skin benefit amniotes?
reduces water loss
88
What are the two groups of amniotes?
diapsids and synapsids
89
What is another word for diapsids?
reptiles
90
When did the earliest reptiles appear?
310 MYA
91
When did dinosaurs originate?
245 MYA
92
Which animals dominated for 135 million years, beginning 245 MYA?
Dinosaurs
93
When did all non-avian species of dinosaurs go extinct?
65.5 MYA
94
Describe diapsids.
- Scales or feathers containing keratin
- Lay shelled eggs on land
- Ectotherms and endotherms
95
What are scales or feathers made of in reptiles?
keratin (protein)
96
What is the benefit of scales and feathers?
prevents desiccation
97
Where and when does fertilization occur in reptiles?
internally, before shell secretion
98
Which reptiles are ectotherms?
snakes and lizards
99
Which reptiles are endotherms?
birds
100
Describe turtles.
Upper and lower shells fused to vertebrate, collarbones, and ribs
Divided into two groups based on neck retraction (Plorodeara and Cryptdeara)
101
What are plorodeara?
group of turtles whose necks retract from the side
102
What are cryptdeara?
group of turtles whose necks retract straight back from their shoulders
103
What were the snakes' ancestors?
burrowing or aquatic lizards
104
How did snakes adapt from lizards?
lost legs
105
What are snakes' trophic levels?
carnivorous with adaptations for hunting and capturing prey
106
What are synapsids?
all mammals
107
- Ponds in Virginia are home to both amphibians, like green frogs, and reptiles like box turtles. Both
of these animals lay eggs. Which of the following observations would help you tell the
eggs of a frog and a turtle apart?
I. Whether
the eggs have a shell or not.
II. Whether
the eggs are found on land or in the pond.
III. Whether the embryo within the egg, which can
be viewed with an x-ray, has a post-anal tail.
1. I
2. I & II
3. I & III
4. d. I, II & III
b. I and II
108
Are birds reptiles or mammals?
reptiles
109
Describe the modifications birds have for flight.
- Honeycombed bones (strong enough, but light)
- Reduced organs (no bladder, 1 ovary (not 2), small gonads)
- Lost teeth
- Feathers
- Large pectoral muscles
110
Why do birds only have 1 ovary?
modification for flight
111
Researchers suspect that early ancestors of birds were flightless but had feathers. What have researchers inferred from this observation?
1. Early feathers were not
aerodynamic, limiting flight.
2. Early birds were too heavy to fly,
even if they tried.
3. Early birds had not yet learned the
mechanics of flight, so they couldn’t use their feathers.
4. Feathers initially evolved for another function.
d. Feathers initially evolved for another function.
112
What are exaptations?
traits that were evolved for one function, but are ultimately useful for something else
113
What do scientists think feathers were originally for?
thermoregulation
114
When did birds evolve from dinosaurs?
160 MYA
115
When did extant species of birds emerge?
65.5 MYA
116
When was the last mass extinction event?
65.5 MYA
117
How are birds different from other animals?
- Large brain, more acute senses than other reptiles and amphibians
- Wings for dispersal
- Beak morphology -> more diet breadth
118
What are the 3 groups of mammals?
Monotremata
Marsupialia
Eutherians
119
What is the ancestral group of mammals?
monotremata
120
What are two animals in the monotremata group?
platypus and echidna
121
What is unusual about monotremata?
mammals that lay eggs; have mammary glands, but lack nipples
122
Where does milk excrete from in monotremata?
Leaks out on stomachs (lack nipples)
123
List three animals that are marsupials.
Opossums, kangaroos, anad koalas
124
How are marsupialia unique?
experience early development in uterus, but complete it outside uterus while nursing (moves into pouch)
125
Which group of mammals has the majority of species?
eutherians
126
What does the complex placenta of eutherians mean?
Offspring are supported longer and develop entirely in the uterus.
127
Why do eutherians lack the epipubic bone?
To allow expansion of abdomen during pregnancy
128
Which mammals have the longest pregnancies?
eutherians
129
- Mammalian
reproduction varies between the three major lineages, but all mammals have
extended parental care. Relative to other animals, what is the consequence of
this extended care?
I. Many offspring
II. Few offspring
III. Offspring with high probability of survival
IV. Offspring with low probability of survival
1. I & III
2. I & IV
3. II & III
4. II & IV
c. II and III
130
What is a derived trait exclusive to mammals?
1. Hair
2. Parental care
3. Ability to learn
4. All of the above
a. Hair
131
What are two non-mammalian groups that can learn?
planarians and insects
132
What are the 7 derived traits of mammals?
- Mammary glands that produce milk to support offspring
- Hair
- Fat layer under skin
- Endotherms - maintain body temperature internally
- Larger brains relative to other groups (exceptions)
- Extended parental care
(long gestation times, lots of care after birth)
- Diverse teeth
133
When did mammal-like traits appear?
300 MYA
134
When did true mammals appear?
200-145 MYA (concurrent with dinosaurs)
135
Why weren't the early mammals species rich?
They arose while dinosaurs dominated.
136
When did the 3 major lineages of mammals arise?
140 MYA
137
When did adaptive radiation occur for mammals?
65.5 MYA (at end of Cretaceous)
138
What is the largest plurality of mammals?
rodents
139
What is unique about rodents?
continuously growing incisors in both jaws; gnaw to wear down teeth
140
Which mammals are the most habitat-diverse?
rodents
141
What roles do rodents have in the ecosystem?
soil aeration and nutrient distribution
hydrology
human disease vectors
142
What are the two types of ungulates?
odd-toed and even-toed
143
What are ungulate hooves made of?
keratin
144
What is the trophic level of ungulates?
herbivores and omnivores
145
What is diverse about ungulates?
cranial appendages
146
What are three examples of ungulates?
cows, sheep, elephants
147
What did cetaceans originate from?
land mammals
148
Describe the first whale.
small deer-like animal with teeth
149
What are whales' sister taxa?
hippos
150
Describe the forelimbs and hindlimbs of cetaceans.
Forelimbs are flippers. Hindlimbs are vestigial.
151
What are the two sub orders of cetaceans?
toothed and baleen
152
```
- Which
of the following traits might give cetaceans an adaptive advantage over sharks (stayed in water),
who have a similar lifestyle?
1. Rear limbs with digits modified
into tail flukes.
2. A blowhole that delivers airs to large lungs.
3. Mineralized teeth for effective
prey capture.
4. All of the above
```
A blowhole that delivers airs to large lungs.
Air has more accessible oxygen than water. Even though coming to surface is energetically costly, it is worth it.
153
What are the two groups of carnivorans?
Feliforma and Caniforma
154
Describe carnivorans.
Eutherians
Sharp teeth and claws
Mostly terrestrial (except seals and walruses)
Skull shape associated with predation (some herbivores)
155
What are the exceptions to the terrestrial carnivorans?
seals and walruses
156
What are the exceptions to the carnivorous carnivorans?
pandas (herbivores)
157
- You come across a skeleton of a tetrapod. To determine if this animal was a reptile or a mammal, you would examine:
1. the size of the ribcage
2. the shape of the teeth
3. the presence of milk-producing glands
4. all of the above
b. the shape of the teeth
158
How are teeth different between reptiles and mammals?
Reptiles have lots of teeth that are the same shape. Mammals have more shape variety.
159
Why can't I use the ribcage's size to differentiate between reptiles and mammals?
Both have well-developed lungs
160
Describe primates.
- Eutherians
- hands and feet adapted for grasping
- flat nails instead of claws
- large brains, short jaws
- eyes look forward
- complex social behavior (not exclusive to primates)
- flexible or opposable thumbs
161
What have primates' hands and feet adapted for?
grasping
162
What are the benefits to primates' front-facing eyes?
improvements to hand-eye coordination
163
What traits are unique to monkeys and apes, not found in basal primates?
opposable thumbs
164
What did apes diverge from?
Old World Monkeys.
165
Describe the phylogeny of apes.
Apes are a monophyletic clade with a single common ancestor.
166
When did apes appear?
They diverged from Old World monkeys 25-30 MYA.
167
Where is the only place non-human apes are found?
Old World tropics
168
What are the four derived traits of hominids?
-
- Upright and bipedal
- Larger brain, complex thought, and tool use and manufacture
- Reduced jawbones and teeth
- Shorter digestive tract
169
What was the first hominid and when did it appear?
Sehelanthropous tchadensis first appeared 6.5 MYA.
170
What separated Sehelanthropous tchadensis from other apes?
More upright
| Reduced canine teeth
171
What was the first hominid?
Sehelanthropous tchadensis
172
What was the second hominid and when did it appear?
Ardipithecus ramidus - 4.4 MYA
173
What was the second hominid?
Ardipithecus ramidus
174
What was unique about Ardipithecus ramidus?
```
Teeth suggest omnivory, not carnivory
Increasingly bipedal (but not entirely)
```
175
Which was the first hominid to walk fully erect?
Australopiths
176
What was the third hominid to appear and when did it appear?
- Australopiths appeared 4-2 MYA
177
What is unique about Australopiths?
- first hominid to walk fully erect
| - human like hands and feet
178
What are the fourth hominids and when did they appear?
Homo habilis appeared 2.4-1.6 MYA
179
What was unique about Homo habilis?
- used tools
- shorter jaw, larger brains
- completely erect
180
What was the fifth hominid and when did it appear?
Homo ergaster (2 MYA - 1 MYA)
181
What was unique about Homo ergster?
-
- larger brains than previous hominids
- no more tree climbing
- smaller teeth
182
What was the sixth hominid to appear and when did it?
Homo erectus (1.8 MYA - 200,000 YA but maybe later)
183
What was unique about Homo erectus?
-
- taller (5-6 ft)
- used fire to cook food
- migrated out of Africa (first time)
184
Which hominid used fire to cook food?
Homo erectus
185
Which hominid migrated out of Africa first?
Homo erectus
186
What was the seventh hominid to appear and when did it?
Homo heidelbergensis (700,000 -200,000 YA)
187
What was unique about Homo heidelbegensis?
- first species to live in exclusively colder climates
| - built shelters
188
What was the first hominid to live in exclusively colder climates?
Homo heidelbergensis
189
What was the eighth hominid to appear? When did it?
Homo neanderthalensis (400,000 - 40,000 YA)
190
When did neanderthals reach Europe?
By 350,000 YA
191
What was unique about Homo neanderthalensis?
- short, stocky bodies: adaptations to cold environments
- made complex tools
- buried their dead (maybe)
192
What is Homo sapiens' sister taxa?
Homo neanderthalensis
193
When did Homo neanderthalensis diverge from Homo sapiens?
400,000 YA
194
- One major trend in the evolution of humans is brain size, which becomes particularly apparent in the genus Homo. The brain is a metabolically costly organ, requiring significant amounts of energy. What is the most likely reason that humans evolved such large brains?
1. Provided early human with unique fight-or-flight reflexes
2. Necessary to facilitate moving bipedally
3. Evolved in response to increased complexity in communication
4. all of the above
c. Evolved in response to increased complexity in communication
195
What is unique about Homo sapiens?
- lighter skeletons
- thin walled skull with a vertical forehead
- smaller teeth
- advanced use of specialized tools (for hunting and fishing)
- developed sophisticated societies and cultural practices
196
How old are Homo sapiens?
200,000 YA
197
When did the first H. sapiens leave Africa?
180,000 YA
198
When did humans make it to the New World?
15,000 YA
199
Early Homo sapiens coexisted with other Homo species. Why are we the only hominins now?
- 50,000 YA, H. sapiens outcompeted other species and replaced them.
- more advanced tools
- elaborate shelters
- social, cultural development (cooperation)
200
- Which of the following characteristics is/are found in all hominins?
I. opposable thumbs
II. fully bipedal
III. tool use
1. I
2. I and II
3. I and III
4. I, II, and III
1. I
Full bipedalism shows up in Lucy (not our first hominin).
Homo habilis (sp) is our first evidenced hominin that used tools.
201
What was the first hominin to use tools?
Homo habilis
202
What is genetic diversity?
heterozygosity within a population
203
What is species diversity?
species richness and abundance
204
What is species richness?
number of different species
205
What is species abundance?
number of individuals in a species
206
What is ecosystem diversity?
interactions between species and environment
207
What happens to ecosystems when the number of species increases?
They become more productive.
208
What are ecosystem services?
functions provided by nature that support humans
209
What are the three kinds of ecosystem services?
- products extracted from ecosystems
- processes that maintain healthy ecosystems
- cultural benefits from ecosystems
210
- Which of the following are ecosystem services?
I. Taxol, a chemotherapy drug from yew trees
II. a hiking trail in Shenendoah National Park
III. an oyster reef that filters water in Chesapeake Bay
1. I and II
2. I and III
3. II and III
4. I, II, and III
d. I, II, and III
211
Why can it be difficult to estimate the monetary value of ecosystem services?
Because many species contribute to multiple ecosystem services.
212
What are some characteristics that make a species vulnerable to extinction?
- how big the species is (large species are long lived and have lower reproduction rates)
- narrow ranges (fewer options for habitats)
213
What is the most problematic thing happening in terms of biodiversity?
habitat loss
214
Describe habitat fragmentation.
When fragment edges have different abiotic conditions; they can have completely different communities, leading to a large impact on diversity
215
What are invasive species?
species with high abundance that affect other organisms and the ecosystem as a whole; not all non-native species
216
What can be the impact of invasive species on native ecosystems?
- reduced species diversity
- changes in genetic diversity (hybridization)
- changes in species interactions
- changes in ecosystem services
217
What is overexploitation?
harvesting past the point where a population can recover
218
What group of species is overexploitation particularly problematic for?
long lived
219
List three groups that have been overexploited recently.
Sardines, pangolins, and conches
220
List 4 examples of global change.
- an increase in atmospheric CO2 has led to a mean global temperature increase of 1 degree Celsius
- Decreased ocean pH
- Sea level rise
- More frequent extreme weather events
221
What are the impacts of global change on biodiversity?
- Habitats become unsuitable
- Resources reduced
- Timing of biological events altered
- Loss of species interactions
222
- Which
of the following statements about threats to diversity is FALSE?
1. Invasive species can reduce species diversity by outcompeting native species.
2. Overexploitation can reduce genetic diversity through the bottleneck effect.
3. Habitat fragmentation leads to new environmental conditions that reduce species diversity
4. Global change leads to lower marine ecosystem diversity through higher ocean temperatures and pH
d. Global change leads to lower marine ecosystem diversity through higher ocean temperatures and pH
223
List the 4 types of tissues.
Epithelial
Connective
Muscle
Nerve
224
What are the shapes of epithelial cells related to?
location
225
What impact does location have on epithelial cells?
determines shape
226
What do epithelial cells do throughout the body?
Cover the outside and line the inside.
Epithelial cells interact with the environment. They are a barrier for threats and are the location of material exchange.
227
What germ layer are epithelial cells derived from?
depends on location
outside - derived from ectoderm
inside - mesoderm or endoderm
228
How are epithelial cells arranged?
in sheets throughout the body
229
How are connective cells arranged?
in cells scattered in an extracellular matrix, found everywhere between other tissues
230
What are 4 examples of connective tissues?
bone, cartilage, fat, blood
231
What do muscle filaments contain?
actin and myosin
232
What do actin and myosin do in the body?
Allow movement in muscle tissues
233
What are the 3 types of muscle tissue?
skeletal
smooth
cardiac
234
What is skeletal muscle tissue?
muscle tissue attached to bones and tendons
235
What is smooth muscle tissue responsible for?
involuntary body activities
236
Where are cardiac muscle tissues found?
heart walls
237
What do nerve tissues do?
receive, process, and transmit information
| They receive cues and signals and send additional signals to the rest of the body, prompting responses.
238
What transmits impulses in nerve tissues?
neurons
239
What does glia do?
supports neurons
240
- Which of the following tissues is MISMATCHED with one of its organ or organ system?
1. Connective: bone
2. Muscle: stomach walls
3. Epithelial: blood
4. Nerve: spinal cord
c. epithelial: blood
241
What is necessary for responding to external environments?
Communication and feedback between cells, tissues, organs, and environment
242
What does the endocrine system use to respond to environment?
hormones
243
Describe the speed and location of the endocrine system's response to external stimulation.
Gradual changes that affect the whole body.
244
What does the nervous system use to respond to environment?
nerve impulses
245
Describe the speed and location of the nervous system's response to external stimulation.
Immediate changes that can be localized or broad
246
What is acclimatization?
physiological adjustment to response to change in environment; a type of phenotypic plasticity
247
Is acclimatization heritable?
no
248
What is adaptation?
changes in phenotype increasing survival and reproduction
249
Are adaptations heritable?
yes
250
What are the two approaches to managing internal environments?
Regulation and Conformation
251
How do regulators manage their internal environments?
maintains internal environment when external environment changes
252
How do conformers manage their internal environments?
internal environment changes as external environment changes
253
What is homeostasis?
maintaining internal environment at relatively constant conditions
254
Name 4 things that must be homeostatic for animals.
temperature
salinity
blood glucose
pH
255
Why is homeostasis necessary?
To maintain enzyme function, metabolic efficiency, and the structural integrity of cells and proteins.
256
What regulates homeostasis?
negative feedback
257
What is negative feedback?
attempts to return to an original state
258
What are circadian rhythms?
daily cycle of physiological patterns; includes temperature, blood pressure, sleep and wake cycles
259
What is needed to maintain circadian rhythms?
minimal cues only
260
What is metabolism?
all chemical reactions within an organism
| energy to fuel cellular processes, to build proteins, lipids, nucleic acids
261
What is a metabolic rate? What is it measured as?
energy used over a period of time
| measured as heat loss, oxygen used, and calories consumed
262
Do smaller mammals have higher or lower relative metabolic rates than larger mammals (per kg)?
higher
263
Why do larger animals have lower relative metabolic rates compared with smaller animals?
Larger animals have proportionally less surface area to support metabolic needs
264
Why does mass-specific basal metabolic rate decrease?
Due to reduced surface area to volume ratio of tissues
265
- An organism has a relatively constant internal temperature during the day and night despite fluctuations of more than 20ºF between 12pm and 12am. When the
seasons change, the organism experiences changes in its phenotype to help maintain its constant internal temperature. This organism is best described as:
1. A regulator that acclimates to its environment.
2. A regulator that adapts to its
environment.
3. A conformer that acclimates to its
environment.
4. A conformer that adapts to its environment
A regulator that acclimates to its environment.
266
- If you compared the metabolic rate of a
reptile and a mammal of approximately the same size, you would find that:
1. The mammal would have a higher MR than
the reptile
2. The reptile would have a higher MR than
the mammal
3. The two animals would have approximately
the same metabolic rate
4. You cannot compare the metabolic rates of
reptiles and mammals because they are measured in different units
Mammals would have a higher MR than the reptile.
| They are regulators, not conformers.
267
- Homeostasis:
1. Will fluctuate more in regulators than in conformers
2. Is primarily driven by positive feedback
3. Is important for enzyme function
4. All of the above
c. is important for enzyme function
268
- An animal’s metabolic rate is related to
1. Its size
2. Its thermoregulatory strategy
3. Its level of activity
4. All of the above
d. all of the above
269
What is are ectotherms?
organisms that use external sources of energy to control body temperature
270
How do ectotherms moderate temperature?
through behavior changes
| ex. snakes bask in the sun
271
What kinds of animals are ectotherms?
reptiles, amphibians, and most marine organisms
272
What are endotherms?
organisms that rely on internal energy (metabolic heat) to control body temperature
273
What are poikilotherms?
animals whose body temperature varies with the environment (conformers)
274
What are homeotherms?
animals whose body temperatures are relatively stable regardless of the environment (regulators)
275
- We can combine terms to provide more specific information about how an organism
thermoregulates. Antarctic marine fish, which use behavior to regulate their
body temperatures, live in an environment that is thermally stable (i.e.,
always the same temperature). These fish are best described as:
1. Homeothermic
endotherm
2. Poikilothermic
ectotherm
3. Homeothermic
ectotherm
4. Poikilothermic
endotherm
c. homeothermic ectotherm
| Homoeothermic because body temperature is stable.
276
Compare ectotherms and endotherms in terms of energy use.
Ectotherms expend less energy to maintain temperature.
Endotherms expend lots of energy to maintain temperatures.
277
Compare activity levels of ectotherms and endotherms during poor conditions.
Ectotherms are inactive under poor environmental conditions because they don’t have the energy to maintain life.
Endotherms remain active in spite of poor environmental conditions and can do whatever they need to regardless of environment.
278
Compare enzymatic function between ectotherms and endotherms.
In ectotherms, enzymes function under a range of internal conditions.
In endotherms, enzymes are optimized for near constant internal conditions.
279
Compare optimization of enzymes in endotherms and ectotherms.
In ectotherms, they use lots of energy to maintain multiple enzymes.
Endotherms have fewer, but optimized enzymes.
280
List 4 methods of changing body temperature.
Evaporation
Radiation
Convection
Conduction
281
What is evaporation?
loss of heat by evaporation of water
282
What is radiation?
emission of electromagnetic radiation, method of changing body temperature
283
What is convection?
when moving air or water removes radiated heat from the surface (allows heat loss or gain depending on temperature difference)
284
What is conduction?
direct heat transfer by contact
285
```
- When taking a hot shower, the primary mechanism that increases your body temperature
is
1. Conduction
2. Convection
3. Evaporation
4. Radiation
```
b. convection
286
How do people manage heat loss and gain?
The conversion of liquid sweat to vapor results in heat loss, cooling the body.
Vasodilation increases heat transfer from the body to the environment.
287
What do mammals do when cold?
Mammals raise fur or feathers when cold to trap warm air.
288
What do animals do in extremely warm temperatures?
hide
289
What are 3 options for animals during extremely cold temperatures?
Hibernation
Torpor
Antifreeze
290
What is torpor?
an extremely short term hibernation
291
How do some frogs survive during extremely cold temperatures?
The antifreeze in their blood allows them to freeze completely and thaw later.
292
What is osmolarity?
the number of molecules of solute per liter of solution
293
What are osmoconformers?
organisms that have the same osmolarity as environment
294
What are osmoregulators?
organisms that control osmolarity independently from environment
295
What does isosmotic mean?
concentration of water in organism = concentration of water in environment
296
What do water and salts do at isosmotic levels?
continuously diffuse
297
What does hyperosmotic mean?
concentration of water in organism < concentration of water in environment
298
What happens to water at hyperosmotic levels?
moves in
299
What happens to salt at hyperosmotic levels?
moves out
300
How do animals handle being hyperosmotic?
They gain water by osmosis constantly (not good). They excrete large amounts of highly dilute urine.
301
What does hypoosmotic mean?
concentration of water in organism > concentration of water in environment
302
What does water do at hypoosmotic levels?
moves out
303
What does salt do at hypoosmotic levels?
moves in
304
How do marine animals deal with being hypoosomotic?
Marine animals often compensate by drinking large amounts of seawater.
305
- All sharks live in marine habitats and are osmoconformers but
must maintain a low concentration of salt in their blood to maintain
homeostatic conditions. Which of the following mechanisms explains how sharks do this?
1. Sharks rely on passive diffusion of
salt out of their bodies and back into the environment.
2. Sharks use active transport to pump salt out of cells for excretion back into the environment.
3. Sharks have specialized gills that physically block dissolved salt ions from entering the body.
4. Sharks make large amounts of highly dilute urine to flush out salt in the body.
b. Sharks use active transport to pump salt out of cells for excretion back into the environment.
They generally conform, but just in case the salt amount gets too high, they have unique adaptations.
306
How do animals maintain water balance on land?
They obtain water through eating and drinking.
Animals lose water through secretions and excretions.
307
What chordate qualities do tunicates have?
only pharyngeal slits. No notochord, post-anal muscular tail, or dorsal hollow nerve chord.
308
Which chordates lack vertebrae?
Lancelets and Tunicates
309
What structures do chordates use for feeding and gas exchange?
pharyngeal gill slits
310
Unlike eutherians, both monotremes and marsupials...
have some embryonic development outside the uterus.
311
Which of the following groups includes members that all have fully opposable thumbs?
a. anthropoids
b. primates
c. Homo
d. apes
a. anthropoids
312
What is genetic diversity's benefit?
Reduces chance of extinction in a population
313
Which of the following is an advantage of excreting nitrogenous wastes as urea rather than as ammonia?
a. urea is less toxic than ammonia
b. urea does not affect the osmotic gradient
c. urea can be removed as a semi-solid paste
d. less nitrogen is removed from the body
a. urea is less toxic than ammonia
