Final Exam part 3 Flashcards
1
Q
What is biogeography?
A
variation in species diversity and distribution across space
2
Q
Biogeographic patterns are influenced by __________.
A
history, evolution, climate, physiology, and local interactions
3
Q
_________ and _______ are the primary drivers of global species distributions.
A
temperature, and precipitation
4
Q
Precipitation varies by _______.
A
Latitude
5
Q
Species diversity varies by ________.
A
latitude
6
Q
Why are the tropics more diverse?
A
- more solar energy
- niche conservatism
- lack of seasonality
- higher diversification
7
Q
Historical biogeography studies how _____________.
A
past environmental factors have shaped current species distributions
8
Q
What is the continental drift per year?
A
2.5 centimeters (1 inch)
9
Q
Biogeographic regions correspond to __________.
A
Earth’s tectonic plates
10
Q
Continental drift has resulted in unique ____________.
A
flora and fauna across continents
11
Q
Biogeographical patterns in species distribution can occur due to _________.
A
past vicariance or dispersal
12
Q
What is species-area relationship?
A
larger regions support more species
13
Q
Why do larger regions support more species?
A
more niche space, larger population sizes leads to lower extinction rate
14
Q
Smaller land areas have _______ species.
A
less
15
Q
Species richness can be affected by (besides size) ___________.
A
distance from a source of species
16
Q
What is the equilibrium theory of island biogeography?
A
Uses an area’s size and distance to a source population to determine species richness
17
Q
The number of species on an island depends on. balance between ____________.
A
Immigration rates and extinction rates
18
Q
What is an equilibrium number of species?
A
the number of species that should theoretically “fit” on an island
19
Q
The equilibrium theory of island biogeography can be used to predict _____________.
A
The regional species pool of many habitats (not just islands)
20
Q
When was the origin of life?
A
3.4-3.8 billion years ago
21
Q
What was the Precambrian?
A
interval between the formation of Earth 4.6 billion years ago and the appearance of most animal groups 541 million years ago
22
Q
What were the key developments of the precambrian?
A
liquid water, life, photosynthesis, oxygen atmosphere
23
Q
Life was exclusively _______ for most of Earth’s history.
A
unicellular
24
Q
What photosynthetic bacteria was responsible for the creation of the oxygen rich atmosphere?
A
Cyanobacteria
25
What was the Phanerozoic eon?
The interval between 541 million years ago and the present
26
What are the three domains of life?
bacteria, archaea, and eukaryotic
27
Archaea are ______ closely related to eukaryotes than bacteria
more
28
When did bacteria emerge?
3.5 billion years ago
29
When did archaea emerge?
approximately 3 million years ago
30
When did eukaryotes emerge?
1.2 billion years ago
31
Bacteria, archaea, and eukaryotes are all ______________.
monophyletic groups
32
Bacteria and most archaea are __________.
prokaryotes
33
What are prokaryotes?
cells that lack a membrane bound nucleus
34
Eukaryotic organisms have cells that have a ______________ nucleus.
membrane-bound
35
Eukaryotes can be ___________ or _________.
single, multicellular
36
Most Eukaryotic organisms are ___________.
protists
37
What is a microbe?
microscopic organisms
38
Bacteria and archaea are __________ and _________.
prokaryotes, microbes
39
The majority of bacteria are ____________.
Unnamed and undescribed
40
Lineages are of bacteria and archaea are _____, __________, _________, and _______.
ancient, diverse, abundant, and ubiquitous
41
How long were prokaryotes the only form of life on earth?
1.9 billion years
42
Bacteria and archaea are the __________ life-forms on earth today.
dominant
43
Where can bacteria and archaea be found?
almost everywhere (diverse habitats)
44
What is a microbiome?
the community of microbes that inhabits a particular area
45
What are extremophiles?
bacteria and archaea that live in high-salt, high-temperature, low-temperature, or high pressure habitats
46
Why are extremophiles a hot area of research?
1. help us understand the origin of life
2. explorations in extraterrestrial life
3. commercial applications
47
Where do chemoorganotrophs get their energy from?
organic molecules
48
Where do chemolithotrophs get their energy from?
inorganic molecules
49
Bacteria and archaea are ____________ diverse.
morphologically
50
How are bacteria and archaea morphologically diverse?
size, shape, and mobility
51
What is cyanobacteria?
photosynthetic bacteria, first organism to perform photosynthesis, origin of oxygen in the atmosphere, origin of chloroplast
52
When did cyanobacteria evolve?
2.5-2.7 billion years ago
53
How does bacteria play a role in nitrogen fixation?
provides usable nitrogen for plants to incorporate into biomass
54
What are the key differences between bacteria and archaea?
1. Bacteria have peptidoglycan in their cell wall
2. Machinery used in the central dogma in archaea are more like those in eukaryotes than bacteria
3. Bacteria are often pathogenic
55
What are pathogens?
bacteria that can cause disease
56
What is virulence?
the ability to cause disease
57
Virulence is a _________ trait.
heritable
58
What do antibiotics do?
kill bacteria or stop them from growing
59
Why do some bacteria and fungi naturally produce antibiotics?
to reduce competition
60
Antibiotics usually target the ___________.
cell wall
61
What does gram stain do?
distinguishes between two general types of bacteria
62
What does gram-positive mean?
Plasma membrane surrounded by a cell wall with extensive peptidoglycan
63
What does gram-negative mean?
plasma membrane surrounded by a cell wall with peptidoglycan and an outer lipid layer
64
Gram-negative bacteria are often more _______________.
virulent and difficult to treat
65
What is a virus?
an obligate, intracellular parasite that causes disease and must replicate within a host
66
Viruses are not __________ and are not made up of _______.
cells, cells
67
Viruses cannot manufacture their own ______, _______, or ________.
ATP, amino acids, nucleotides
68
Viruses do have _______.
hereditary material
69
What are two common morphologies of viruses?
Genetic material enclosed by a protein capsid or genetic material enclosed by a capsid and a membrane envelope
70
What are the steps of viral replication within a host?
1. Viral genome enters a host bacterial cell
2. Viral genome is transcribed; viral proteins are produced
3. Viral genome is replicated
4. Particles assemble inside host
5. Particles exit to exterior
6. Free virions in tissue or environment are transmitted to new host
71
Viruses are always made up of _____ and _____.
protein, genetic material
72
Are viruses organisms?
No
73
What are the requirements of life?
1. consists of cells
2. replicates
3. contain hereditary information
4. acquire and use energy
5. product of evolution and evolves today
74
Why do researchers construct phylogenetic trees for specific lineages of viruses?
To understand the origin and emergence of new diseases
75
Viruses are grouped by ________.
genetic material
76
What are viruses further classifies by?
1. virion and genome morphology
2. nature of host species
3. how the virus replicates in the host
77
What kind of virus is Covid?
ssRNA (single stranded)
78
Viruses from the same lineage can have different ______ and cause different types of _______.
hosts, diseases
79
Viral evolution can be very _______.
fast
80
What are the fundamental features of eukarya?
1. most eukaryotic cells are larger than bacteria and archaea and have more organelles
2. all have nuclear envelopes, the defining feature of eukaryotes
3. multicellularity is rare in bacteria and archaea but has evolved multiple times in eukaryotes
4. reproduce asexually through mitosis or sexually through producing gametes
81
How do bacteria and archaea reproduce asexually?
through fission
82
What were the features of the first eukaryote?
a single celled organism with mitochondria, and nucleus and membrane system, and a cytoskeleton but no cell wall
83
What were the first eukaryotes?
protists
84
What are protists?
all eukaryotes that are not plants, fungi, or animals
85
What occurs in mitochondria?
cellular respiration
86
How did mitochondria originate?
Via endosymbiosis when a bacterial cell took up residence within another cell 2 billion years ago
87
Mitochondria replicate by _____ and _______ is independent of division by the host cell.
fission, duplication
88
Mitochondria have their own ______ and manufacture some of their own _______.
ribosomes, proteins
89
Mitochondria have _________.
double membranes
90
Mitochondria have their own ________, which are circular
genomes
91
How did chloroplasts originate?
Via endosymbiosis when a protists engulfed a cyanobacteria
92
What led to chloroplasts in other lineages?
secondary endosymbiosis
93
How did the nuclear envelope originate?
Via infoldings of the plasma membrane
94
Why was the nuclear membrane favorable?
it separated transcription and translation
95
Chloroplast of some algae have an _____ ______ that contains _______ which supports the endosymbiosis theory.
outer layer, peptidoglycan
96
Why are protists paraphyletic?
They have no defining feature that is only found in protists and no other organisms.
97
Protists tend to live in habitats where they are surrounded by _______ most of the time.
water
98
What is a life cycle?
The sequence of events that occur as individuals grow, mature, and reproduce.
99
Protist reproduce asexually via _________ and sexually through ________.
mitotic division, meiotic cell division
100
Many single celled protist spend their life in either _______ or _______ form.
haploid, diploid
101
What form do most multicellular protist spend their life cycle in?
alternating between haploid and diploid
102
What is a sporophyte?
A diploid form that produces haploid spores through meiotic cell division
103
What is a gametophyte?
A haploid form that produces gametes through mitotic cell division
104
What is a spore?
A single haploid cell that divides mitotically to form a multicellular gametophyte.
105
What is a gamete?
A single haploid cell that fuses with another gametes to produce a diploid sporophyte.
106
Many protists are _____ because they have evolved structures for _________.
mobile, movement
107
Can protists be heterotrophs, autotrophs, or both?
both
108
What is phagocytosis?
The process of ingesting food much larger than individual molecules
109
How do protists consume bacteria, archaea, and other protists?
Through ingestive feeding (feeding through phagocytosis) or absorptive feeding (taking nutrients up directly from the environment)
110
Some protists have __________ for support or protection.
external shells
111
Some protists ______ humans.
parasitize
112
______ is one of the world's most deadly infections, which is caused by a protist (Plasmodium)
Malaria
113
Harmful ________ can release toxins that accumulate in shellfish and harm people.
algal blooms
114
What are dinoflagellates?
photosynthetic protists
115
What is phytoplankton?
Photosynthetic protists that drift in open oceans and lakes. Basis of the food chains and freshwater and marine environments
116
What is zooplankton?
Drifting organisms, usually microscopic, that feed on phytoplankton
117
What is kelp?
a multicellular brown algae (protist)
118
Land plants evolved from an ancestral protists in the _____ _____ lineage.
Green algae
119
green algae are the closest living relative to land plants and form a ______ _________ with them.
monophyletic group
120
What led to the diversification of terrestrial life?
When land plants diverged from green algae approximately 475 million years ago
121
What are the defining characteristics of plants?
1. Multicellular, eukaryotic organisms
2. Cell walls made of cellulose
3. Specialized reproductive organs
4. Have chloroplasts and almost all perform photosynthesis
122
Why did plants transition to land?
Land offers plants resources like more light and carbon dioxide (new niches)
123
What adaptations prevented water loss when plants transitioned to land?
cuticle and stomata
124
What is a cuticle?
Waxy, watertight sealant that covers the above ground parts of plants.
125
What are stomata?
An opening surrounded by specialized guard cells that can open and close to prevent water loss and allow the exchange of carbon dioxide
126
Stomata close in _____ __________ and at _____ to prevent water loss.
dry conditions, night
127
Stomata open in ____ _______, allowing the uptake of carbon dioxide.
wet conditions
128
What adaptation provided protection from harmful UV radiation when plants transitioned to land?
Flavonoids
129
What are flavonoids?
UV-absorbing compounds which accumulate on plants and act as sunscreen for leaves and stems
130
What adaptation allowed land plants to move water from tissues with direct access to it to tissues without direct access?
Vascular system
131
What does the vascular system do?
Transports water from roots to above ground systems
132
The evolution of _____ drove the evolution of the vascular system by providing ______ _______ for plant tissues, allowing upward growth.
lignin, structural support
133
What do tracheids do?
Allowed for more efficient water transfer through gaps in the secondary lignin wall.
134
What do vessel elements do?
Reduce resistance and make water movement more efficient to create a continuous pipe-like structure.
135
In what order did the vascular system evolve?
1. Simple water conducting cells
2. First vascular tissue (found in fossils)
3. Tracheids (found in vascular plants)
4. Vessel elements (found in gnetophytes and angiosperms)
136
What are the four groups of land plants ?
1. Nonvascular plants
2. Seedless plants
3. Gymnosperms
4. Angiosperms
137
What are the characteristics of nonvascular plants?
Lack of a vascular system, low sprawling growth habit, anchor to substrate using rhizoids, grow in moist habitats, depend on water for reproduction
138
Do nonvascular plants have stomata or cuticles?
No, they live in moist environments.
139
What types of plants are nonvascular plants?
liverworts, mosses, and hornworts
140
What are the characteristics of seedless plants?
Conducting tissues with cells reinforced by lignin, depend on water for reproduction
141
What types of plants are seedless?
ferns, club mosses, and horsetails
142
The evolution of ______ and _______ allowed for reproduction on dry land.
seeds, pollen
143
What is pollen?
A male gametophyte surrounded by a protected coat to prevent drying.
144
What are seeds?
A zygote produced by fertilization, surrounded by a protective coating.
145
What do seeds allow for?
Nourishment of zygotes and for offspring to disperse form parents
146
The evolution of pollen an seeds led to a ______ __ _____ _____ about 365 million years ago.
radiation of seed plants
147
________ produce seed and pollen grains, but do not produce flowers.
Gymnosperms
148
What plants are examples of gymnosperms?
Palms and evergreens
149
What is a flower?
A reproductive organ
150
What is the stamen?
The male reproductive organ of a flower where meiosis occurs, producing pollen grains.
151
What does the stamen consist of?
Anther and filament
152
What is a carpel?
The female reproductive organ of a flow in which meiosis occurs to produce eggs.
153
What does the carpel consist of?
Stigma, style, and ovary
154
The evolution of flowers allowed for the evolution of _____.
fruit
155
Fruits increase _____.
dispersal
156
What is fruit?
A structure that develops an ovary and contains one or more seeds
157
What are angiosperms?
flowering plants
158
What is adaptive radiation?
A single lineage produces a large number of descendent species adapted to a wide variety of habitats.
159
The evolution of flowers led to an _______ _________.
adaptive radiation
160
What are angiosperms traditionally split into?
monocots and dicots
161
What is the issue with just classifying angiosperms as monocots and dicots?
Dicots are not a monophyletic group, so they were reclassified as edicots and magnoliids
162
All plants show __________ __ __________.
alternation of generations
163
What is the nonvascular life cycle dominated by?
gametophytes
164
What life cycle came first: sporophyte-dominant or gametophyte-dominant?
gametophyte-dominant
165
What types of plants spend much of their life as sporophytes and have complicated reproductive structures?
Angiosperms and gymnosperms
166
Why did sporophyte-dominant life cycles evolve?
Sporophyte-dominant life cycles were advantageous because diploids can respond to varying environments more efficiently (more genetic diversity)
167
What two things did seeds and pollen allow for?
reproduction on dry land and dispersal
168
What did specialized reproductive organs allow for?
Embryos to be nourished by the parent plant
169
What stage does dispersal occur in: haploid or diploid?
diploid
170
What are the benefits of seed dispersal?
reduced competition, new niches, and no reliance on water
171
What allowed for the evolution of animal pollination?
Flowers
172
What is pollination?
The transfer of pollen from one plant's stamen to another plant's carpel
173
What is the directed-pollination hypothesis?
Natural selection has favored flower scents, shapes, and colors that attract particular types of pollinators
174
What are the benefits of pollination?
cross fertilization (increases genetic diversity, reduces inbreeding) and increased gene flow
175
What determines the energy available to other organisms?
plant community structure
176
Plants make life on earth ______.
possible
177
Plants provide ________ _________.
Ecosystem services
178
What are fungi?
Eukaryotes that occupy terrestrial environments
179
Are fungi autotrophs or heterotrophs?
Heterotrophs
180
How do fungi get their energy?
They release their digestive enzymes into the external environment to absorb small molecules
181
Many fungi live in ________.
symbiosis
182
Fungi are both _______ and _________.
parasitic, mutualistic
183
Are fungi more closely related to land plants or animals?
Animals
184
What key morphological traits do fungi and animals share?
1. synthesize chitin
2. Flagella of spores and gametes are similar to those observed in animals
3. Both store food to make glycogen
185
What is chitin?
A tough, structural material
186
What two growth forms do fungi exhibit?
Yeasts and mycelia
187
What are yeasts?
single- celled forms
188
What is mycelia (mycelium)?
Multicellular, filamentous structures
189
Why are mycelium dynamic?
They grow in the direction of food sources and die back in areas without food
190
When does the body shape of fungus change?
Almost continuously throughout its life
191
What adaptation supports the external digestion and absorptive lifestyle of fungi?
Mycelium
192
What are hyphae (singular form: hypha)?
The filaments making up a mycelium
193
Most hyphae are divided into cell walls called _________, which gaps for exchange of materials.
septa
194
What are coenocytic hyphae?
Hyphae with no septa and the nuclei are scattered across the mycelium
195
Do fungi have long distance transport systems?
No
196
Why are mycelium highly efficient at absorbing nutrients?
They are thin, branching networks (high surface area: volume ratio)
197
Where are fungi most abundant and why?
Moist habitats because they dry out easily
198
Spores are resistant to ______.
drying
199
Fungi reproduce using ______.
spores
200
What are conidia?
asexual spores produced by mitosis from haploid mycelium
201
What are mating types?
genetically distinct hypha from different individuals
202
What is plasmogamy?
When hyphae from two different mating types grow near each other and fuse to form a hybrid cell
203
What is a heterokaryotic mycelium?
When two different mating types are in one mycelium
204
What is karyogamy?
When in a heterokaryotic mycelium, pairs of unlike nuclei fuse to produce a diploid nuclei (zygote)
205
What happens after karyogamy?
The diploid zygotę divides via meiosis to produce haploid spores (genetically distinct)
206
What form do most fungi spend the majority of their life cycle in: haploid, diploid, or heterokaryotic?
haploid
207
What are the reproductive structure of fungi made of?
Hyphae (the only part of the fungus exposed to air)
208
Do hyphae absorb food?
no
209
What are the four key types of sexual reproductive structures in fungi?
1. swimming gametes and spores
2. zygosporangia
3. basidia
4. asci
210
What are chytrids and where do they primarily live?
Species with swimming gametes, primarily in water and wet soils
211
What are zygosporangia?
Spore producing structures formed when hyphae are yoked (Haploid hyphae from two individuals meet and become joined in a spore producing structure)
212
What are species with zygosprangia called?
zygomycetes
213
Is the zygomycete life cycle primarily haploid, diploid, or heterokaryotic?
Haploid
214
What are basidia?
Club-shaped cells at the end of the hyphae where meiosis occurs, forming 4 spores (mushrooms, brackets, and puffballs)
215
What are species with basidia called?
basidiomycetes or "club fungi"
216
Do basidiomycota spend their life cycle primarily haploid, diploid, or heterokaryotic?
haploid
217
What are asci?
sac-like cells at the end of the hyphae where meiosis and one round of mitosis occurs, forming 8 spores.
218
What are species with asci called?
ascomycetes or "sac fungi"
219
Do ascomycota primarily spend their life cycle in diploid, haploid, or heterokaryotic form?
haploid
220
Fungi lineages are linked to production of different ______________ __________.
reproductive structures
221
Which two groups of fungi collapsed into a polytomy?
chytrids and zygomycetes
222
Which groups of fungi are monophyletic groups?
glomeromycota, basidiomycota, and ascomycota
223
What are saprophytes?
Fungi that digest dead plant material
224
Why are fungi efficient decomposers?
1. Extracellular digestion
2. Breakdown of lignin
3. Fungi can digest cellulose
225
How do saprophytic fungi impact the terrestrial carbon cycle?
They release the carbon stored in the lignin of plants
226
Decomposers release useable ______ and ________ from dead organisms back into the soil.
nitrogen, phosphorous
227
What are microsporidia?
A lineage of parasitic fungi
228
Parasitic fungi can effect ______ and threaten ____ __________.
humans, crop production
229
What are mycorrhizae?
Fungi that live in close association with plant roots (mutualistic). Fungi benefit through nutrients received from the plant, plant benefits because the fungi release nitrogen and phosphorous back into the soil.
230
What are endophytes?
fungi that live between and within plant cells (mostly mutualistic)
231
What are the key traits shared by all animals?
1. Multicellular eukaryotes whose cells lack a cell wall
2. Heterotrophs
3. Move under their own power at some point in their life
4. Have nerve cells and muscle cells (except sponges)
232
When did the radiation of animals begin?
550 million years ago during the Cambrian explosion
233
Common ancestor to animals evolved about ________ million years ago. The first animal appear about _______ million years ago.
800, 700
234
What were the first animals?
early sponges
235
What caused the Cambrian explosion?
1. Higher oxygen levels
2. Rise of algae
3. Evolution of predation
4. New niches beget more new niches
236
How many phyla of animals do biologist recognize?
30-35
237
What are the key themes in animal evolution?
1. evolution of animals is more complicated than a smooth transition from simple to complex
2. many key innovations did not arise at once
("deep homology" followed by homoplasy)
3. evolution did not stop within any of the lineages
238
How can we study the evolution of animals?
1. comparison of body plans
2. comparison of developmental processes
3. comparative genomics
4. the fossil record
239
What is epithelium?
A layer of tightly joined cells that cover the exterior and/or interior surface of animals
240
What necessary genes do sponges have that are used animals for development?
1. specialization of cell types
2. regulation of cell cycling and growth
3. developmental signaling and gene regulation
4. programmed cell death
5. recognition of self and non-self
241
What genes for contractile proteins do sponges have?
actin and myosin
242
What are diploblasts?
Two types of embryonic tissue
243
What is endoderm?
Inner layer that gives rise to the lining of the digestive tract
244
What is the ectoderm?
Outer layer that gives rise to the skin and nervous system
245
What are triploblasts?
three types of embryonic tissue
246
What is the mesoderm?
Middle layer that gives rise to the circulatory system, muscle, and internal structures
247
What are the three major animal groups?
Non-bilateral phyla, protostome phyla, and deuterostome phyla
248
What are characteristics of the non-bilateral phyla?
Radial and diploblastic. Use a hydrostatic skeleton ( tissue supported by fluids)
249
What are characteristics of the protostome phyla?
bilateral and triploblastic
250
What are characteristics of the deuterostome phyla?
bilateral and triploblastic
251
Bilateral symmetry is linked to the development of a _____ _______ and ______________.
nervous system, cephalization
252
What is a coelom?
An internal, usually fluid filled body cavity lined with mesoderm (synapomorphy of bilateral lineages, but lost in some lineages)
253
What is segmentation?
The division of the body or part of the body into a series of similar structures
254
What are characteristics of invertebrates?
no backbone, segmentation in body plan
255
What is another name for the protostome phyla and why is it called that?
"first mouth" named after the embryonic development of the mouth before the anus
256
What is another name for the deuterostom phyla and why is it called that?
"second mouth" named after the embryonic development of the anus before the mouth
257
The vast majority of animals are _________.
protostomes
258
What is important about arthropods?
They are the most abundant and diverse animals observed in both aquatic and terrestrial ecosystems
259
What are the three key features that characterize arthropods?
1. segmented body
2. an exoskeleton
3. joint appendages
260
What is an exoskeleton?
hard external skeleton made of chitin
261
What are joint appendages?
joints between segments and the legs
262
Insects have ________ and __ ___.
wings, siz legs
263
Insects are diverse and abundant and play crucial roles in _______ and ______ ecosystems.
aquatic, terrestrial
264
What are the four key requirements of chordates?
1. pharyngeal slits or pouch
2. dorsal hollow nerve chord
3. notochord
4. a muscular, post-anal tail
265
What are vertebrates?
organisms that have a vertebrae and a cranium
266
What is a vertebrae?
a column of cartilaginous or bony structural support
267
What is a cranium?
a bony, cartilaginous, or fibrous case that encloses the brain
268
What were the early key innovations of vertebrates?
jaws, lungs (lost in sharks & rays and coopted into swim bladders in ray-finned fishes), and bones
269
What are bones?
dense tissue consisting of cells and blood vessels in a matrix of calcium that form an endoskeleton in vertebrates
270
Evolution of limbs allowed the __________.
transition onto land
271
What was the "Limbs from Fins Hypothesis"?
The fossil record links the limbs of the ancestors of today's lungfish to those of the earliest land-dwelling vertebrates
272
What are tetrapods?
organisms with two pairs of limbs
273
Why were tetrapods a key morphological innovation?
They allowed vertebrates to exploit the ecological opportunities of the terrestrial environments, leading to diversification
274
What are amphibians?
the first tetrapods to live on land (adults feed on land but lay their eggs in water)
275
what does ectothermic mean?
individuals do not use their internally generated heat to regulate their body temperature
276
What did amniotes allow for?
allowed for reproduction on land
277
What is an amniotic egg?
Eggs that have a protective covering that reduces the rate of drying, allowing species to lay them outside of water
278
Are reptiles more closely related to amphibians or mammals?
mammals
279
What is an endotherm?
organisms that regulate their body temperature with energy produced internally
280
Mammals have _______ and _____.
lactation (mammary glands), fur
281
What is lactation?
The production of milk which nourishes offspring
282
Mammals are the only vertebrate group with _____ ________ and _____ which makes suckling possible.
cheek muscles, lips
283
Hair is primarily made of _____.
Keratin
284
What contains the amniotic egg in most mammals?
The placenta
285
What is the placenta?
An organ containing maternal and embryonic tissues, provides oxygen and nutrients to the developing embryo
286
What are the benefits of the placenta?
1. Offspring develop at a more consistent temperature
2. Offspring are protected
3. Offspring are portable
287
What lineage are humans a part of?
Primate
288
Humans evolved from the common ancestor of all ______ animals.
placental
289
What are the traits of primates? (6 of them)
1. Hands and feet that are efficient at grasping
2. Flattened nails instead of claws
3. Brains that are large relative to body size
4. Color vision
5. Complex social behavior
6. Extensive parental care
290
Humans are the only living hominid that is fully ____.
bipedal
291
What is bipedalism?
The ability to walk upright on two legs
292
Humans share ____ of our genome with chimpanzees.
95%
293
When did humans begin to split off from chimpanzees?
6 million years ago
294
What percentage does the brain make of body mass in Humans and what percentage of energy does it use?
2% of mass, 20% of energy
295
Approximately when did Homo sapiens evolve?
300,000 years ago
296
How much of the human genome is of Neanderthal origin?>
4%
297
Why did the Neanderthals go extinct?
1. Inbreeding, causing a decline in genetic diversity
2. Climate change and competition for resources with humans
3. Humans had more complex social behaviors
4. Hybridization between Neanderthals and humans
5. Conflict between Neanderthals and humans
298
What did the rise in human populations cause?
global change
299
What is the current population of Humans on Earth?
Approximately 8 million
300
What type of population growth curve does the human population represent?
density independent, exponential
301
Will humans reach density dependent growth and overshoot carrying capacity?
Yes, if populations growth rate does not decline more.
302
Is population growth rate in Humans currently declining or growing?
declining
303
What is fertility rate?
Average number of surviving children that a woman has in her lifetime
304
What fertility rate would result in a population growth rate of zero?
2
305
What is the current fertility rate?
2.5
306
What will the population reach if the growth remains the same?
nearly 17 billion
307
What will the population reach if if the growth rate reaches 2?
A little over 11 billion
308
What was the growth rate in the 1950's?
5
309
What are endangered species?
Species whose number has decreased such that it will go extinct without conservation action
310
Rate of species extinctions are increased with rapidly growing _____ ________.
human populations
311
What threats from human activities act on species endangerment/ extinction?
1. Habitat destruction and degradation
2. Overexploitation
3. Invasive species and disease
4. Pollution
5. Climate change
