Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIO120 > Test 2 > Flashcards

Test 2 Flashcards

1
Q

What are the two main approaches to defining a species

A

Taxonomic
-based primarily on distinct measurable differences
Biological
-based on inter-fertility among individuals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Biological species concept…when,who, what, theory

A

-Mayr 1942
Reproductively isolated

-focuses on the processes
-geographic isolation alone is not sufficient
-isolation does not have to be absolute
-must be possibly interbreeding in the wild
-does not apply well for bacteria, asexuals, highly self-fertilizing species or fossils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where does speciation occur?

A

Often called geographic speciation
-due to involvement of geographical isolation
Allopathic speciation much more common & easier to evolve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What causes reproductive isolation …all the steps
(5)

A

-finding a compatible mate & mating, fertilization, development & growth of zygote, adult & reproduction, growth/survival/reproduction of offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Different kinds of barriers …7

A

-Pre-zygotic …prevent mating or fertilization
-geological, ecological
-temporal, behavioural (mate recognition)
-mechanical (genital structure compatibility)
-cellular (sperm-egg compatibility)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Pre-zygotic isolation in apple maggot flies

A

-host shift after arrival of domesticated apples in 1800s
-differences in timing of host plant fruiting (apple vs haw)
-different timing of fly mating on preferred host plant
-reduced fly gene flow by 94% in sympatry (same region)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Pre-zygotic isolation in abalone

A

-binding of sperm lysin preteen to egg viteline envelope receptor (VERL) required for fertilization
-molecular “lock and key”
-lysin/VERL interaction has coevolved
-different evolutionary changes in different species
-causes reproductive isolation due to fertilization incompatibility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Post zygote barriers …intrinsic and extrinsic

A

Prevent proper functioning of zygotes once they are formed
-caused by combinations of genes with low fitness in the hybrid
—-intrinsic: in viability, sterility, or abnormal development of hybrids
—-extrinsic: ecological mismatch of hybrid phenotype to environment

-not directly favoured by natural selection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Intrinsic post zygotic isolation hybrid examples

A

Mule is a sterile hybrid cross of
-male donkey 62 chromosomes
-female horse 64 chromosomes

Hinny
-male horse
-female donkey

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Genetic distance and post-zygotic isolation in fruit flies

A

-The more that fly pairs are genetically differentiated, the more likely they are to be reproductively isolated
-review graph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Extrinsic post-zygotic isolation: example of poorly adapted hybrids

A

-mullerian mimicry in heliconius butterflies
-hybrids have aberrant colour patterns
-higher predation
-lower mating success

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Is adaptive evolution required for speciation

A

-local adaptations by different populations can lead to reproductive isolation and speciation
-distinct evolutionary responses to different selective pressures
-LA no absolatuly mecessay, but accelerates population divergence and evolution of RI

-termed ecological speciation

-much current research aims to determine:
-the biotic and abiotic agents of selection
-the underlying ‘speciation genes’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Eda in fish

A

-a gene for understanding adaptation and speciation during colonization of freshwater lakes
-present in marine environments against large fish predation

-absent in freshwater
-increases growth rate
-greater winter survival
-earlier breeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Review graphs

A

📈📉

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Bop

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Adaptive radiation

A

The evaluation of ecological and ohenotypic diversity within a rapidly multiplying lineage as a result of speciation
-originates from a single common ancestor
-the process results in an array of many species
-the species differ in traits allowing exploitation of a range of habitats and resources

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Four features of adaptive radiation.

A
  1. Recent common ancestry from a single species
  2. Phenotype-environment correlation
  3. Trait utility
  4. Rapid speciation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What causes adaptive radiation

A
  1. Ecological opportunity
    -abundant resources
    -few competitors
    -often encountered on oceanic islands or their aquatic counterparts
    -
  2. Origin of a key innovation
    -toepad in anoles
  3. High rates of speciation characterize the class
    -test by comparing island to mainland class
    -
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Hybridization

A

-the exchange of genes between species as a result of occasional inter-species mating
—-sometimes can reverse speciation process to merge two groups into one
-varies across tree of life
—-common in plants and fish, rare in mammals
-can result in complex patterns of variation
——can be evolutionarily significant for speciation, especially by polyploidy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Polyploidy

A

An organism, tissue, or cell with more than two complete sets of homologous chromosomes

-allopolyploidy
—-arises from duplicated karyotype following hybridization between species
—commonest type of polyploidy
(AAxAA—>AAAA)

-autopolyploidy
——-arises from duplicated karyotype within a species
(AA—>AAAA)

At

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Alloploidy

A

An allopolyploid is an individual having two or more complete sets of chromosomes derived from different species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Autopolyploidy

A

Autopolyploidy appears when an individual has more than two sets of chromosomes, both of which from the same parental species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Evolutionary significance to polyploidy

A

They are reproductively isolated from their diploid parents
—hence a form of sympatric speciation
They exhibit novel phenotypes
—allows exploitation of new habitats
Often show hybrid vigor due to heterozygosity, particularly in allopolyploids
Polyploid origin for approx 50% of flowering plants
—many crops plants & invasive species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Binomial nomenclature

A

Species naming
Carolus Linnaeus 1707-1778
-hierarchical system of classification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the purpose of biological classification

A

Name is s key shared information on an organism
Predictive power
Enables interpretation of origins and evolutionary history

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Taxon def and order

A

A single names taxonomic unity at any level
-kingdoms
-phyla
-classes
-orders
-families
-genera
-species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Taxonomy

A

The theory and practice of classification and naming

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Systematics

A

The study of biodiversity and the evolutionary relationships among organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

A phylogenetic tree
Point out 6 things

A

Terminal nodes :taxa
Terminal branches: accumulated evolutionary change
Internal branches: accumulated evolutionary change
Internal nodes: common ancestor, speciation
Outgroup taxon
I group taxon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Why conduct phylogenetic analysis

A

Understand life history
Undedtand large-scale patterns of evolution
Understand how many times traits have evolved, how fast, under what condition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Monophyletic group

A

Complete set of species derived rom a common ancestor
-a taxon whose members are derived from two or more ancestral forms not common to all ancestors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Paraphyletic group

A

Contains some, but not all species derived from a common ancestor
-a single ancestor gave rise to all species in this group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Ancestral vs derived traits

A

A trait shared with a common on ancestor
A trait that differs from the ancestral trait in a lineage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Homology v Homoplasy

A

Similarity of traits due to shared ancestry
Similarity of traits as a result of convergent evolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Cichlid fishes

A

Are an example of convergent evolution in feeding strategies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Why do we care about molecules

A

All life is related through branching descent
Common genetic code is evidence that all life is related
Evolutionary relationships among species are reflected in their DNA and protein
—learning about protein function in one species can tell us about its function in others

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Species relationships from DNA sequencing

A

Genes or parts of a gene can be sequenced for different species
Species can be assessed for changes in the sequence of nucleotides
Changes can be used to infer relationships in a branching diagram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Key innovations in phylogenies

A

-origin of novel trait resulting in adaptive radiation
- arriers of the treat can exploit new resources or sets of habitats
-usually associated with repaid evolutionary diversification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Why do some groups have more species than others -
-sister h=group

A

-with one phylogenetic comparison it is difficult to say a key trait is involved
-replicate comparisons of multiple groups adds more evidence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Her ivory associated with higher diversification rate is an example, fo what

A

Convolution between insects and plants likely drives rates of speciation in herbivores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Other impacts associated with greater diversification

A

-species with more sexual selection
-animal pollination in plants
-increased dispersal
-increased range size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Lamarck says species will become what with time

A

More complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Major transition in evolution

A

Greater complexity arises from greater cooperation among previously independent units
-complexity = specialization

-a small number of events led to major changes in how inheritance worked
-previously independently evolving units merged, leading to higher-level complexity & specialization through division of labour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the unity of selection

A

-most phenotypic traits we study in organisms arose due to selection that increases the fitness of individuals
—may or may not be good for the SPECIES
—individual selection usually stronger than group selection

-traits that are good for the species but that reduce firmness of the individual connot be favoured by the indivisible selection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

When is cooperation adaptive

A
  1. High relatedness
    -genes that lead to helping relatives can spread via natural selection
  2. Reciprocal altruism
    -in cases where organisms repeatedly encounter each other
  3. BUT cooperation sometime breaks frown ….cheated
46
Q

What is the target of selection

A

Genes
Selection on an individual is a kind of cooperation
-different parents into one, segregation/recob/random mating ensures independently passed on

47
Q

Two problems of cooperation

A

How do higher levels of organization stay cooperative ?
To what extent can cooperation break down?

48
Q

How do genomes stay cooperative

A

-many features of individual organisms prevent competition within an individual
——prevents evo within individuals
——align fitness interests

-ensures that many genes succeed by enhancing the fitness of the organism

49
Q

How does an individual genome stay cooperative

A
  1. Mitosis and meiosis
    -alleles don’t compete
    -fair representation of gene variations
  2. Development and multicellularity
    -staring from a single cell prevents initial competition among cell lineages
  3. Unioarental inheritance of organelles
    -chloroplasts and mitochondria replicate asexually
    -prevents competition within cells of different organelle genomes
50
Q

Explain fair meiosis

A

Keeps genome cooperative
-50% 50% division of alleles

51
Q

Cheating a fair meiosis

A
  1. Meiotic drive
    -biased transmission
    -spread to higher frequency even while reducing the individuals fitness
  2. Over-replication
    -Transposable Element (TE)
    -self replicating segments of DNA
    -TE replication separated from cellular replication
    -ensure their own over-representation of offspring
52
Q

Meiotic drive in drosophila

A

Segregation distorted locus
-ssxSs
All offspring were Ss
Expect 50%
-S allel prevents proper s sperm formation
-counteracting restorer alleles are favoured at other genes in the genome to silence the S allele

53
Q

How do genomes not explode from transposition

A

Alleles arose elsewhere in genomes that silence TEs will be favoured by individual selection
-mechanismisn controlling DNA & histone methylation
-piRNAs and RNA interface may have evolved as silencing mechanisms

Transposition-selection balance
-transposition is a form of mutation that can disrupt a gene

54
Q

Transposition-selection balance

A

-transposition increases TE abundance
-natural selection against harmful efffects on the organism reduces abundance of chromosomes copies with most TEs
—overall abundance results from a balance between these opposing forces

55
Q

Mitochondrial transmission

A

-lack of mitosis and meiosis by plastids sets up potential for spread fo selfish eleements

56
Q

How do mitochondria stay cooperative

A

Uniparental plastid I driven e stringly reduces competition within individuals
-consistent with hypotheses that it evolved to maintain coooperation

57
Q

New conflicts due to unipafental inheritance

A

Conflict of interest
-maternal inheritance of cytoplasmic genome
-biparental inheritance of nuclear genome

Mitochondrial mutations that enhance maternal fitness can spread
-even if cost is severe to male fitness

58
Q

Cytoplasmic male sterility in plants

A

-new mutations in the mitochondria that make hermaphroditic plants male sterile can spread
-favour mitochondria, transmission
-can reduce fitness as a whole

-leads do evo of Mum lead restorer alleles that re-enable fertility through pollen
——-arms race to co evolution of CMS & restorer genes

59
Q

How do collections of cells stay cooperative

A
  1. Starting from a single cell reduces competition within individual s
  2. Separation of Germaine with limited numbers of cell divisions inhabits transmission of selfish cell lineages
  3. Tumour suppressors. Other features inhibit unregulated cell division
  4. BUT SOMATIC MUTATION IS INEVIT8SBEL IN LONG-LIVED MULTICELLULAR ORGANISMSS
60
Q

Cancer as a selfish cell lineage

A

-spread commonly in tissue that is relatively undifferentiated
—evolves resistance to treatment/immune system
-illustrated the shirt-sightedness of the evolutionary process

61
Q

Pests and evolution: the problem

A

We use chemicals to combat pests and pathogens
We create strong selective pressure for resistance

62
Q

Where does resistance come from

A

Q. Pre-existing genetic variation in the population
2. Gene flow
3.new mutations

63
Q

Which weeds have more pre-existing resistance

A

Outcrossing
It’s less in selfing weeds

64
Q

Can we stop herbicide resistance

A
  1. Multi-herbicide treatment
    -make new adaptation less likely
    -requires more comp,ex adaptation
  2. Rotation of different kinds of herbicides
    -weeds regularly hit by different selection pressures

BUT COULD SELECT FOR GENERALIZED RESISTANCE

65
Q

Graph for evolutionary rescue

A

Nike swish

66
Q

Malaria and mosquitos

A

700 k deaths a year
Prevention = insecticides
Strong selective pressure on mosquitoes has led to rapid evolution of resistance

67
Q

Evolution-prof solutions

A

Tailor insecticide applicarion to knowledge of mosquito generation times & spatial distribution
Goal: minimize selection for mosquito resistance while still reducing malaria transmission

68
Q

Less aggressive drug treatment of malaria in mice resulted in…

A

-less evo of resistance
-reduced infectiousness
-similar health outcomes

69
Q

Multidrug cocktails slow evolution of HIV resistance how

A

-Simple mutations unlikely to confer resistance to multiple drugs with different mechanisms of action
-lower viral loads make multiple mutations less likely

70
Q

True or false skin cancers evolve drug resistance

A

True

71
Q

Evolutionarily informed cancer treatments

A

Strong, prolonged selection pressures using the same chemotherapy drugs may not be the best solution as it selects for resistance
-cycling drugs, multi drug cocktails, lower doses of drugs
- e better option?
-ethical considerations make tests of theory for human application challenging

72
Q

Biodiversity and extinction

A

-Extinction is a permanent elimination of a species
-extinction is a normal evolutionary process
——-99% of all species that have ever lived are now extinct
———in unddisturbed ecosystems, extinction rates have been estimated at one species loss every 10 years
-astoundingly increased rates of extinction during the past century ——-massive habitat destruction particularly in tropical regions
——at least 4000 to 6000 species per year

73
Q

Five genetic issues and conservation biology

A

Loss of genetic diversity
loss of heterozygosity
inbreeding depression
fixation of deleterious alleles
in ability of populations to adapt

74
Q

What are the factors to an of evo rescue

A

-Depends on population size, beneficial mutation rate, how much fitness was reduced

75
Q

Ecology is what

A

-how organisms interact with each other and their environments
-the distribution and abundance of species
-the structure and function of ecosystems
-the science of biodiversity

76
Q

Who developed the endosymbiosis theory for the origin of mitochondria

A

-Lynn margulius

77
Q

How many species are there

A

Globally
-too many to count
-many (>85%) still unknown to science
-a eccentric estimate from rates of new taxa described cam to 8.7 million
-just eukaryotes

78
Q

Rank of biodiversity in the three level of life

A

Bacteria
Eukaryota
Archaea

79
Q

Population
Ecological community
Ecosystem
DEFINE

A

All individuals of the same species in one place at one time
-a;l the species living together in one place at one time
-all species plus non-living environment

80
Q

Example of animal from,entire with large range and small range

A

Mountain lion …all of the America pretty much
Pika …west of North America only

81
Q

What determines where a species lives

A

Dispersal ——> abiotic conditions ——-> species interactions

82
Q

What limits a species range

A

Dispersal
Climatic or other inexhaustible conditions
Food or other exhaustible resources
Species interactions
——-these are all gradients, there are ideal and unideal areas of the gradient

83
Q

Ranges of tolerances in environment gradients
Draw the graph

A

Bell shaped symeptrical slope
-ends are lethal zones

84
Q

The sixth extinction

A

Ongoing mass extinction
-human activities
232%of known vertebrates species are decreasing in pop size or range

85
Q

What determines abundance

A

Malthus
Influenced Darwin
-population growth
-human pop. S can’t grow faster than our resources
-population decline when resources decline

-Darwin inspired and writes the same for all species …competition
-resources are abundant …competition gets stronger

86
Q

Ecological niche

A

Combination of physical tolerances and resource requirements of a species
-Hutchinsonian niche: an n-dimensional hyper volume

87
Q

Global gradients

A

-temperature
-rainfall
-seasonality

88
Q

Temperature is a function of

A

Latitude

89
Q

Seasonality in high latitude is a function of…

A

Te,persture

90
Q

Seasonality in low latitudes is a function of…

A

Rainfall

91
Q

Rainfall depends on …

A

Atmospheric circulation, offshore currents, rain shadow

92
Q

Hadley cells

A

Heated air rises from near the equator and cools at 5/10c/km
Water vapours condenses and fall as rain near the equator
Air warms as it falls
Dry, high pressure air hits at 30+/- degrees latitude

93
Q

Name the atmospheric cells and their directions

A

Hadley cells-north
Ferrel cells-south
Polar cells- north

94
Q

Hadley cell s meet where

A

The inter-tropical convergence

95
Q

Draw the intertropical convergence in July and January

A
96
Q

Coriolis effect

A

The earths rotation deflects winds
-objects appear to be deflected eastwards as they move away from the equator and deflected as they move towards the equator

97
Q

Horse latitudes

A

No wind …doom horses to preserve fresh water
-30 degrees

98
Q

Landmass serves as …

A

Wind blocker

99
Q

General trends of terrestrial vegetation

A

Vegetation growth increases with moisture and temp
Becomes predictable as biomes
Seasonality is secondarily important

100
Q

Look over Whittaker’s diagram

A
101
Q

Describe climate patchiness

A

Maritime is more climate moderated, continental kore extreme
—-oceans provide thermal inertia
Precipitation:
Orographic precipitation-air forces up mountains undergoes cooling into rainfall
Rain shadow -leeward mountain sides are dry

102
Q

Niche limits versus geographic range limits… What are some of the exceptions

A

Transcendent biomes = ecological versatility, super generalist
-Not at limits because of recent history, limited by other organisms

103
Q

Ecological niche modelling

A

Otherwise known as species distribution modelling
-uses data from species present distribution to predict where species can live
-useful for modelling biological invasions how species range may shift due to climate change spread of vector borne diseases

104
Q

Observed range shifts data from 2003 and 2011

A

2003 = species move polewards at a rate of 6.1 km per decade
2011 = species move polewards at a rate of 16.9 km per decade

105
Q

What do physiologist study what do ecologist study what is physiological ecology

A

——study how organisms acquire energy and nutrients and tolerate physical conditions
——-ecologist study how organisms deal with their environment and how the environment limits where they live
—— Eco physiology is simply the study of physiology in the contacts of an organisms ecology

106
Q

What are the core ideas of physiological ecology

A

-Ranges of tolerance ultimately limit distribution
-organisms are complex chemical reactions
-reactions occur best at the optimum temperature and Osmetic conditions where fitness is maximized
-many mechanisms for homeostasis have evolved to challenge hostile environments
-maintenance of homeostasis requires energy and is often limited by constraints and trade-offs

107
Q

Poikilotherms

A

Lack physiological means to deviate from environmental temperature fluctuate greatly reptiles
—amphibians fish and invertebrates

108
Q

Homeotherms

A

Must regulate heat balance to keep internal temperature within a narrow range
—-Requires far greater energy then poikilotherms

109
Q

Describe the modes of heat gain or heat loss

A

Radiation = heat transfer by electromagnetic radiation
conduction = transfer by direct contact with substrate
convection = heat transfer mediated by moving fluid
evaporation = efficient cooling from wet surfaces
redistribution = circulatory system redistribute heat among body parts

110
Q

Explain Bergman‘s rule and Allen’s rule

A

Body size to surface area versus appendages/shape

111
Q

Explain countercurrent circulation

A

Arteries and veins should be oppressed in appendages to conserve heat and separated in appendages to shed heat
-Countercurrent flow maintains this gradient so heat is always flowing from outgoing blood to incoming blood

112
Q

Explain weasels as a trade off to heat dynamics

A

Weasels are active all year and despite their warm weather adapted shape they live in the cold
-Staying warm takes up to 50 to 100% greater metabolic demand
-However their shape makes them much more effective predators to the pray they hunt underground

BIO120 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions