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Exam 3 Flashcards

1
Q

Biological Evolution

A

Change in the characteristics of a population of organisms that occurs over the course of generations

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2
Q

Species

A

A group of individuals that regularly breed together and are generally distinct from other species in appearance or behavior

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3
Q

Population

A

Subgroup of a species that is somewhat independent from other groups

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4
Q

Natural selection

A

Process by which individuals with certain traits have greater survival and reproduction than individuals who lack these traits, resulting in an increase in the frequency of successful alleles and a decrease in the frequency of unsuccessful ones

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5
Q

Scientific theory

A

Body of scientifically accepted general principles that explain natural phenomena

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6
Q

Theory of evolution

A

Theory that all organisms on Earth today are descendants of a single ancestor that arose in the distant past

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7
Q

Common descent

A

The theory that all living organisms on Earth descended from a single common ancestor that appeared in the distant past

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8
Q

Homology

A

Similarity in characteristics as a result of common ancestry

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9
Q

Homologous structures

A

Structures that are so similar that they imply a common ancestor

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10
Q

Analogous structures

A

Features that serve a similar function but are derived from different ancestors

Example: bee wing and bat wing

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11
Q

Anatomical homology

A

Anatomical parts are considered to be homologous when they are evolutionarily derived from a single feature in a common ancestor

Example: the same bones in a human’s arm, a cat’s paw, a whale’s fin, and a bat’s wing

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12
Q

Developmental Homology

A

a comparison between the embryos of different species

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13
Q

Fossils

A

Remains of plants or animals that once existed, left in soil or rock

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14
Q

Fossil Record

A

Physical evidence left by organisms that existed in the past

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15
Q

Vestigial Traits

A

Structures that have no apparent function and appear to be residual parts from a past ancestor are called vestigial structures. Examples of vestigial structures include the human appendix, the pelvic bone of a snake, and the wings of flightless birds.

Traits would not exist unless the organism’s ancestors possessed them; this is strong evidence of common ancestry and change over time

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16
Q

Suboptimal Structures

A

our knees and spine were not originally meant for walking upright
our respiratory system crosses our digestive system which can cause choking
evolution can only modify existing structures and functions
organisms “make do” with suboptimal designs

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17
Q

Biogeography

A

The study of the geographic distribution of organisms

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18
Q

Radiometric dating

A

Technique that relies on radioactive decay to estimate a fossil’s age

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19
Q

Explain the process of evolution by natural selection

A

natural selection is the mechanism that drives evolution; individuals best suited to the environment survive and produce more offspring, driving change over time

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19
Q

Summarize and explain the evidence supporting the theory of evolution

A

vestigial traits: traits that are reduced or rudimentary compared to the same traits in an organism’s ancestors or relatives

anatomical homology: same bones in different species - homologous structures derived from a common ancestor

biogeography: organisms in different environments in similar geographic areas are often alike because populations migrate and adapt to new environments but resemble their ancestors

developmental homology: comparative embryology - the comparison of early stages of animal development reveals many similarities between organisms indicating common ancestry

suboptimal structures: evolution can only modify existing structures and functions

molecular homology: primate chromosome composition is quite similar; chimps/gorillas/orangutans have 24 pairs of chromosomes, humans have 23 pairs
also…. the genetic code is essentially universal, suggesting all species descended from a common ancestor

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20
Q

Compare evolution to alternative hypotheses for life’s origin and diversity

A

Common Descent: species do change over time, and new species can arise. all species derive from a common ancestor
Supported by a wide variety of evidence

Static Model: species arise separately and do not change over time
Rejected; earth is far older than 10,000 years and earth has clearly changed over time

Transformation: species arise separately and change over time in order to adapt to the changing environment
Rejected; evidence of relationships among organisms abound

Separate Types: species change over time, and new species can arise, but not from a common ancestor. each group of species derives from a separate ancestor that arose independently
Rejected; universality of DNA, genetic code, and cell components are evidence of a single origin of life

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21
Q

Tuberculosis

A

Degenerative lung disease caused by infection with the bacterium Mycobacterium tuberculosis; destroys the lungs ability to provide oxygen to the bdody

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22
Q

Antibiotic-resistant

A

Characteristic of certain bacteria; a physiological characteristic that permits them to survive in the presence of particular antibiotics

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22
Q

Antibiotics

A

A chemical that kills or disables bacteria

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23
Fitness
Relative survival and reproduction of one variant compared with others in the same population
24
Combination Drug Therapy
The use of more than one drug simultaneously to treat a disease. Often used for disease organisms that mutate quickly or are difficult to control to combat the problem of drug resistance
25
Adaptations
Trait that is favored by natural selection and increases an individual’s fitness in a particular environment
26
Explain how drug resistant strains of tuberculosis have evolved
spontaneous gene mutations in M. tuberculosis that render the bacteria resistant to the most commonly used anti-TB drugs evolution of drug-resistant M.tb depends on bacterial fitness, strain’s genetic background and its capacity to adapt to the surrounding environment
26
Explain the relationship between natural selection and genetics (the modern synthesis)
random gene mutations produce variation natural selection acts on that variation ultimately, natural selection acts on the genes
27
List the four observations that lead to the inference of natural selection
1) individuals within populations vary 2) some variation can be passed on to offspring 3) populations overproduce 4) survival and reproduction are not random
28
What are the misconceptions about natural selection?
individuals cannot evolve you can't evolve on purpose natural selection does not produce "perfect" organisms natural selection does not have a goal
29
Summarize the relationship between natural selection and drug resistance in disease-causing microbes
using one type of drug for too short of a time period selects for antibiotic resistant bacteria by using combination drug therapy, bacteria are very unlikely to be resistant to multiple drugs, therefore stopping drug resistance
30
Spatial isolation
A mechanism for reproductive isolation that depends on the geographic separation of populations
31
Behavioral isolation
Prevention of mating between individuals in two different populations based on differences in behavior
32
Mechanical isolation
A form of reproductive isolation between species that depends on the incompatibility of the genitalia of individuals of different species
33
Temporal isolation
Reproductive isolation between populations maintained by differences in the timing of mating or emergence
34
Gamete incompatibility
An isolating mechanism between species in which sperm from one cannot fertilize eggs from another
35
Hybrid inviability
Hybrid individuals that do not survive past the embryonic stages
36
Hybrid sterility
The creation of a hybrid that is sterile and unable to produce offspring
37
Allopatric Speciation
Geographic barrier separates populations The populations may change overtime to become new species
38
Sympatric Speciation
New species will originate with no geographic barriers between populations Can occur when populations occupy a new niche
39
Gradualism
Model says that new species occur by the gradual accumulation of small changes across a long time
40
Punctuated equilibrium
Model says that species usually evolve relatively quickly, followed by long periods of stasis (no change). This model is more often supported by the fossil record.
40
Biological race
Populations of a single species that have diverged from each other
41
Allele frequency
The percentage of the gene copies in a population that are of a particular form, or allele
42
Genetic drift
Change in allele frequency that occurs as a result of chance; Often seen in human populations
43
Founder effect
Type of sampling error that occurs when a small subset of individuals emigrates from the main population and begins a new population, leading to differences in the gene pools of both
44
Population bottleneck
Dramatic but short-lived reduction in population size followed by an increase in population
45
Sexual selection
Form of natural selection that occurs when a trait influences the likelihood of mating
46
Assortative mating
Tendency for individuals to mate with other individuals who are like themselves
47
Explain what a species is based on the biological species concept
a species is a group of individuals that, in nature, can interbreed and produce fertile offspring, but cannot reproduce with members of other species
48
Explain why human “races” are not biological groups
human races are not biological groups; humans have never been truly isolated from each other and therefore cannot have evolved into separate biological races
49
Population growth rate
How fast a population changes in size over time growth rate = birth rate - death rate
50
Density-dependent factors
Any of the factors related to a population’s size that influence the current growth rate of a population—for example, communicable disease or starvation
50
Demographic transition
The period of time between when death rates in a human population fall (as a result of improved technology) and when birth rates fall (as a result of voluntary limitation of pregnancy)
51
Carrying capacity
Maximum population that the environment can support
52
Density-independent factors
Any of the factors unrelated to a population’s size that influence the current growth rate of a population—for example, natural disasters or poor weather conditions
53
Net Primary Productivity (NPP)
A measure of the amount of food energy available on the planet; We currently use 1/3 of the land NPP
54
Nonrenewable resources
Resource that is a one-time supply and cannot be easily replaced
55
Demographic momentum
Lag between the time that humans reduce birth rates and the time that population numbers respond
56
Population pyramid
A visual representation of the number of individuals in different age categories in a population
57
List density independent factors that affect population growth
weather fluctuations natural disasters
58
List the factors that have influenced the human population growth rate
improved medical care (vaccines and antibiotics) improved sanitation improved nutrition through industrial agriculture all have driven population growth
59
Discuss factors that may affect the Earth’s carrying capacity for humans
the environment can only support so many people we need enough clean water, air, and energy for everyone we will eventually run out of non-renewable resources
60
What factors would help reduce population growth rates?
Improved female literacy
61
List density dependent factors that affect population growth
food water space/shelter accumulation of waste spread of disease
62
Extinction
Complete loss of a species
63
Biodiversity
Variety within and among living organisms
64
Habitat
Place where an organism lives
65
Food Chain
The linear relationship between trophic levels from producers to primary consumers, and so on
66
Food Web
The feeding connections between and among organisms in an environment
67
Introduced species
A nonnative species that was intentionally or unintentionally brought to a new environment by humans
68
Community
A group of interacting species in the same geographic area.
69
Mutualism
Interaction between two species that provides benefits to both species
70
Predation
Act of capturing and consuming an individual of another species
71
Competition
Interaction that occurs when two species of organisms both require the same resources within a habitat; competition tends to limit the size of populations
72
Competitive exclusion
Reduction or elimination of one species in an environment resulting from the presence of another species that requires the same or similar resources
73
Keystone species
A species that has an unusually strong effect on the structure of the community it inhabits
74
Ecosystem
All of the organisms and natural features in a given area
75
Explain the evidence that suggests we are entering a mass extinction
current extinction rates are 50-100x higher than normal
76
List and describe the causes of extinction
habitat destruction and fragmentation: habitat destruction is the most serious threat, fragmentation harms large predators who need large spaces to hunt introduced species: organisms brought by human activity to new environments, often devastate existing species overexploitation: due to use for food, pets, house plants, medicinal value, etc. pollution: most pollutants come from agriculture (herbicides and pesticides, CO2 is also a pollutant
77
Explain the three types of species interactions
predation: act of capturing and consuming an individual of another species mutualism: interaction between two species that provides benefits to both species competition: interaction that occurs when two species of organisms both require the same resources within a habitat
78
List ways in which you can help prevent the loss of biodiversity
reduce fossil fuel use eat less meat and dairy recycle and reuse reduce the use of wood and paper products financial aid to developing countries join organizations, write politicians, and educate others
79
List and describe the consequences of extinction
loss of resources: loss of foods, building materials, medicines, etc. without bees to pollinate our food, it will become more expensive with less variety disruption of communities: predation, mutualism, and competition can be disrupted, derailing the web of life disrupted energy and chemical flows psychological effects: because of the evolutionary nature of our ancestors, we have a genetic desire to connect with nature

General Biology (6 decks)

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