BIO 15O FINAL Flashcards
1
Q
Biodiversity is measurable at three levels:
A
Genetic level= variability within species
Species level= variability among species
Ecosystem level= variability among ecosystems
2
Q
Three domains of life:
A
Archaea, eukarya and bacteria
3
Q
Population
A
interbreeding group of individuals. Populations exchange genes
4
Q
Purpose variability within a population
A
- some genetic variants have advantages over others
- natural selection can act on variation
5
Q
What if populations are separated and cannot exchange genes (two processes can occur)?
A
- Genetic divergence
- Speciation
6
Q
Species richness
A
Number of species in a specific area
7
Q
Species evenness
A
How close in population size each species is
8
Q
Areas with greater geographic variation usually has
A
a higher biodiversity
9
Q
Novel ecosystems
A
Made by humans (example: landfill)
10
Q
Evolution
A
Change in genetic composition of a population, from one generation to the next
11
Q
Natural Selection
A
Causes adaption inorganisms, acts on variability
12
Q
Adaptation
A
Inherited trait that enhances the fitness of an individual in its environment
13
Q
What is the Hardy-Weinberg Law of Equilibrium used for?
A
model used to determine whether evolution has occurred or not. Is a population in equilibrium or is it evolving?
14
Q
Hardy-weinberg equations
A
- p+q=1
- 2p+2pq+2q=1
p= dominant allele frequency
q= recessive allele frequency
15
Q
There are 5 main evolutionary mechanisms:
A
- Natural selection
- Genetic drift
- Gene flow
- Mutations
- Non-random mating
16
Q
Genetic drift
A
Change in the populations’ allele frequencies due to a random event (has larger effect on small populations)
17
Q
Two mechanisms associated with genetic drift:
A
- Bottleneck effect
- Founder effect
18
Q
Bottleneck effect
A
Reduction in population size due to a disturbance usually changes genetic composition and often causes a decrease in genetic variation
19
Q
Founder effect
A
Small number of individuals from a large population colonize a new area
20
Q
Gene flow
A
When two separated populations can exchange genes in the future. New alleles are randomly brought in by migration.
21
Q
Difference between gene flow and genetic drift?
A
Genetic drift removes alleles from the population, gene flow introduces new alleles and become part of the gene pool
22
Q
Gene pool
A
All the genes in a population at a given time
23
Q
Microevolution
A
Small changes in the gene pool of a population. Refers to evolution within populations
24
Q
Mutation
A
Random changes in the genetic make-up
25
Beneficial mutation
Mutation that increases the fitness of an individual
26
Deleterious mutation
Mutation that decreases the fitness of an individual
27
Neutral mutation
Mutation that has no effect on the fitness of an individual
28
Three modes of natural selection:
1. Stabilizing selection
2. Directional selection
3. Disruptive selection
29
Stabilizing selection
The intermediate phenotypes have a higher fitness than extreme phenotypes
30
Directional selection
Individual with one of the extreme phenotypes that has a higher fitness than intermediate phenotypes
31
Disruptive selection
BOTH extreme phenotypes are favored at the expense of the intermediates (can facilitate sympatric speciation)
32
Speciation occurs when...
The separated populations are no longer able to produce viable, fertile offspring
33
Speciation underlies...
The diversity of life on earth
34
Speciation can occur with or without
Natural selection
35
Sympatric speciation
1. New species evolves from the population while still inhabiting the same geographic region
(REPRODUCTIVE isolation)
2. Can occur instantaneously through formation of polyploid offspring
36
Disruptive selection can lead to..
Sympatric speciation if strong enough and sustained long enough
37
Allopatric speciation
New species evolves from the population due to GEOGRAPHIC isolation
Example: mountain range, rivers, etc.
38
2 Types of allopatric speciation
1. Dispersal
2. Vicariance
39
Vicariance
separation of populations due to geographical barrier
40
2 types of dispersal and what they mean
1. Active dispersal (organisms move from one location to another w/o assistance)
2. Passive dispersal (organisms need assistance to move locations. Mostly plants using wind)
41
Biological species concept
Species are groups of interbreeding individuals that are reproductively isolated from other such groups
42
In order for biological species to form...
Reproductive isolation must take place
43
Ecological species concept
A species can be characterized by its ecological niche (usually used for bacteria)
44
Pre-zygotic isolation
In most cases, mating does not even occur
45
Post-zygotic isolation
Reproductive isolation that occurs after members of two different species have mated and produced a hybrid offspring
46
What are the 5 Mechanisms of PRE-zygotic isolation?
1. temporal isolation
2. behavioral isolation (courtship behavior differs)
3. habitat isolation (allopatric speciation)
4. mechanical Isolation
5. gametic barrier
47
Examples of temporal isolation
1. isolated by time
2. diurnal vs. nocturnal
3. seasonal differences in activity
48
Mechanisms here are often genetic incompatibility:
What are 2 mechanisms of POST-zygotic isolation
1. reduced hybrid viability (first generation hybrids are sometimes fertile, but do not produce fertile offspring)
2. hybrid sterility (offspring is sterile, meaning it cannot sexually reproduce)
49
Polyploidy
Organisms with more than two paired chromosomes
50
Polyploidy results from...
Error during meiosis or mitosis which results in doubling of chromosome numbers. Results in massive mutation
51
Allopolyploidy
Parents of two different species mate resulting in their offspring having two different sets of chromosomes
52
Autopolyploidy
All the chromosomes involved are from the same species
53
According to Darwin's theory: T or F
All species, past and present, trace their ancestry back to a common ancestor
True
54
What does a phylogenetic tree tell us?
The hypothesized evolutionary history of a group of organisms
55
All organisms require a __________ source and a __________ source
Carbon & Energy
56
An organisms that consumes organic C compounds that were produced by other organisms and energy from consuming other organisms
chemoheterotroph
57
An organism that synthesizes their own inorganic C compounds and uses light as energy source
photoautotroph
58
2 normal forms of metabolism
1. Cellular respiration- Aerobic
2. Oxygenic photosynthesis
59
3 alternative forms of metabolism
1. Anaerobic cellular respiration
2. fermentation
3. Anoxygenic photosynthesis
60
What is Ecology?
The study of how organisms interact with one other and with their physical
environment
* Study of factors that influence the distribution (where they live) and abundance (how
many individuals) of organisms
61
Abiotic factors
physical or non-living features
62
Biotic factors
biological (living) factors
63
Niche:
a complete description of the role
a species plays in its environment and of
its requirements, both abiotic and biotic
64
Fundamental Niche
Abiotic and food/resources
65
Realized Niche
Abiotic and food/resources
Species interactions
66
As cell size INCREASES, SA/V...
Decreases
67
As cell size DECREASES, SA/V...
Increases
68
Oxidation
Energy is released. Donates electron and energy
69
Reduction
Energy is needed. Accepts electron and energy. Reduced molecules store energy
70
Synapomorphy
Similar shared traits derived from a common ancestor
71
Apamorphie
New trait
72
As cell size DECREASES, SA/V...
Increases
73
Endosymbiotic theory
-bigger cell's membrane surrounded bacteria cell
-newly engulfed bacterium was not destroyed, it became the new mitochondria
74
Endosymbiosis
When an organism of one species lives inside another
75
Endotherms
Generates internal heat, depending on presence of food to burn
76
Ectotherms
An animal that depends on external sources for body heat
ex: the sun
77
How do animals regulate temperature?
Moving to areas that are optimal for their needs
78
Tradeoff of being an endotherm:
Can live in cold habitats, but cannot live on little food
79
Tradeoff of being an ectotherm:
Cannot live in cold habitats, but can live where there is little food
80
Bryophytes
Plants w/o vascular tissues (non-vascular) or roots
81
Stomata
Small pores on a leaf that allow for water, light, and gases to go in and out of the plant
82
Guard cells
Open and close the stoma
83
Transpiration
Water is taken up by diffusion, but delivered by bulk flow
84
Community
– Populations of different species that overlap in
time and space and (typically) have a long co-evolutionary
history (in contrast to invasive / non-native species)
85
Keystone Species
* Species that have a much greater impact on the distribution and
abundance of surrounding species than its abundance would suggest.
86
Top down regulation of populations in communities:
Community structure is regulated by higher trophic levels
87
Bottom up regulation of populations in communities:
community structure is determined by amount of resources at lower trophic
levels
88
Angiosperms
Flowering plant, seeds protected by carpels
89
Gymnosperms
Seeds are unprotected
90
What are the four levels of organization in ecology
individual
population
community
ecosystem
91
Genetic Diversity:
Total genetic information contained within all
individuals of a population
92
Horizontal Gene Transfer:
Horizontal Gene Transfer: Exchange of genes with others in the same
generation
93
Alleles:
Different versions of the same gene
94
Adaptations :
A heritable trait that increases fitness in a given
environment AND the spread of advantageous traits in the population
95
Taxonomic Species diversity:
total number of species in an area
96
Genetic diversity:
total genetic information contained within all individuals of a population,
species, or group of different species
97
Functional diversity:
Elements of biodiversity that influence how an ecosystem functions.
Species have ”functional roles” in an ecosystem
98
Monomer of carbohydrates
monosaccharides
99
Benefit of sexual reproduction:
Produce genetically diverse offspring
100
Benefit of asexual reproduction:
1. Organisms don't have to spend time and energy searching for a mate
2. Produces a lot of offspring at a fast pace
3. Bacteria can transfer their DNA to other species
101
How do prokaryotes reproduce:
Binary fission (asexual reproduction)
102
What is the result of binary fission?
2 daughter cells that are identical to each other and the original parent cell
103
Zygote
Sex cell
104
In sexual reproduction, the parent cell is... (haploid/diploid)
Haploid
105
Eukaryotes can reproduce by:
Mitosis and/or Meiosis (primarily the use of meiosis)
106
Mitosis is needed for:
Asexual reproduction
107
Two ways that unicellular eukaryotes ASEXUALLY reproduce:
1. Binary fission
2. Budding (yeast)
108
Types of ASEXUAL reproduction in multicellular eukaryotes:
1. Fission
2. Budding (Forms on parent, then breaks off and lives on its own)
3. Fragmentation (Piece of individual breaks off and regenerates the rest ex: sea sponge)
109
Hypertonic solution
Higher solution content in the surroundings (usually the ocean), water rushes OUT
110
Hypertonic cell
Higher solution content in the cell (usually in freshwater), water rushes IN
111
Hypotonic cell
Higher solution content in the surroundings (usually animals living in the ocean), water rushes OUT
112
What is Isotonic?
When concentrations are the same inside and outside the cell
113
Asexual Reproduction
Production of offspring
that are genetically
identical to the parent.
Doesn’t require
fertilization or mating
114
Sexual Reproduction
two gametes provide
information to make
genetically unique
offspring. Requires
fertilization & meiosis.
115
Incomplete dominance
heterozygous condition produces an intermediate trait
116
codominance
two alleles are equally dominant, both appear in the phenotype
117
gene pool
all genes in a population in a given time
118
phylogenetics
the evolutionary development and diversification of a species or group of organisms, or of a particular feature of an organism.
119
Homeostasis
When organisms actively regulate and maintain a constant
internal (physiological) state in the face of changing
environmental conditions
120
Thermoregulation
is the ability of an organism
keep its temperature within certain boundaries
121
osmoregulation
the maintenance of constant osmotic pressure in the fluids of an organism by the control of water and salt concentrations.
122
