Evolution And Diversity Of Life Flashcards
1
Q
What does Charles Darwin’s theory of common descent state?
A
All organisms, both living and extinct, can be traced back to a single common ancestor
2
Q
How can lineages in Darwin’s theory be visualized?
A
As a series of branches that grow into an evolutionary tree
3
Q
What is phylogeny?
A
The branch of biology that studies the evolutionary history of organisms
4
Q
What is taxonomy?
A
The field of biology that names and organizes species based on their similarities
5
Q
In taxonomy, how are closely related species classified?
A
They are placed in the same group
6
Q
In taxonomy, how are more distantly related species classified?
A
They are joined at higher levels of organization
7
Q
Who was Carl Linnaeus?
A
Carl Linnaeus (1707-1778) was a Swedish botanist and zoologist.
8
Q
What did Carl Linnaeus study?
A
He studied the differences and similarities in the biological structure of organisms.
9
Q
What system did Linnaeus use to group species?
A
He used a nested hierarchical system of classification.
10
Q
What is morphology?
A
Morphology is the branch of biology that studies the form of organisms and relationships between their structures.
11
Q
What are the eight hierarchical groupings used to classify species?
A
The eight taxa are: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
12
Q
What is the singular form of taxa?
A
The singular form of taxa is taxon.
13
Q
Who developed the system of binomial nomenclature?
A
Linnaeus developed the system of binomial nomenclature.
14
Q
What does binomial nomenclature use to name species?
A
It uses the combination of the names of the genus and species of the organism.
15
Q
What is a genus?
A
A genus references a specific group of organisms.
16
Q
Are genus names unique?
A
Yes, genus names are unique, with a few exceptions.
17
Q
Can a genus name be used in different kingdoms?
A
Yes, a genus name may be used once in each kingdom.
18
Q
What is the species epithet?
A
The species epithet is the second word in the scientific name generated by binomial nomenclature.
19
Q
What are species epithets?
A
Species epithets are simple adjectives.
20
Q
Can a single species epithet be used more than once?
A
While a single species epithet can only be used once per genus, epithets can be repeated across many different genera.
21
Q
How should the name of an organism be written?
A
Both the genus and species should be in italics, and the genus name should be capitalized while the species name should not.
22
Q
How has a species been historically defined?
A
A species has been defined as a reproductive community of populations that are reproductively isolated from others and occupy a specific niche in nature.
23
Q
What is the evolutionary species concept?
A
The evolutionary species concept defines a species as a single lineage of ancestor-descent populations that maintains its identity from other lineages and has its own evolutionary tendencies.
24
Q
What does it mean for a species to evolve separately?
A
A species is a specific lineage evolving separately from others.
25
What is the phylogenetic species concept?
The phylogenetic species concept considers two genetically similar populations as different species when they are geographically isolated and each carries unique morphological differences.
26
Which species concept is more commonly used today?
The phylogenetic species concept is more commonly used today.
27
What does phylogeny refer to?
Phylogeny refers to the evolutionary relationships among organisms.
28
What does phylogeny shed light on?
Phylogeny sheds light on the divergence of species through history.
29
How is phylogeny depicted?
Phylogeny is depicted using a phylogenetic tree with branches and nodes.
30
What do branches represent in a phylogenetic tree?
Branches represent lineages in a phylogenetic tree.
31
What do nodes depict in a phylogenetic tree?
Nodes depict common ancestors in a phylogenetic tree.
32
Are the relationships in a phylogenetic tree confirmed?
No, they are hypotheses because scientists can't confirm exact relationships.
33
What is a phylogeny considered to be?
A phylogeny is considered an estimate or educated guess based on scientific data.
34
Can phylogenies be updated?
Yes, phylogenies may be updated or corrected as new evidence comes to light.
35
What is a phylogeny?
A phylogeny is reconstructed by investigating the genetic, physiological, or morphological traits of different species to create a hypothesis about how those species are related.
36
What is the difference between homology and homoplasy?
Homologous characters are derived from a common ancestor, while homoplastic characters are analogues that evolve independently due to similar selective pressures.
37
Can you give an example of homologous characters?
An example of homologous characters is the tail of a monkey and the tail of a cat.
38
Can you give an example of homoplastic characters?
An example of homoplastic characters is the wings of a bird and the wings of a bat.
39
What is a clade?
A clade is a group of related species that share a derived character, which is a trait that differs from the ancestral state.
40
What are synapomorphies?
Shared, derived characters are called synapomorphies.
41
What is a cladogram?
A cladogram is used to depict the evolutionary relationships among different species or groups.
42
What are basal groups?
Lesser derived clades are basal groups of lower taxa that are placed nearer to the 'root' of the tree.
43
What are sister taxa?
Neighboring groups that are closely related are often called 'sister taxa.'
44
What is an outgroup?
An outgroup is a single species/group that’s related to all the others in the tree but is still distinct.
45
What is the purpose of an outgroup?
Outgroups are used to determine ancestral character states.
46
What can evolutionary relationships revealed by phylogenetic studies be used for?
They can be used in taxonomic classification.
47
What is a clade?
A clade is a monophyletic taxon that includes all members of a group and their most recent common ancestor.
## Footnote
Example: mammals and insects.
48
What is a paraphyletic taxon?
A paraphyletic taxon contains a common ancestor but leaves out some of its descendants.
## Footnote
Example: invertebrates and protists.
49
What is a polyphyletic taxon?
A polyphyletic taxon doesn't include the common ancestor to all of its members.
## Footnote
Example: marine mammals and flying vertebrates.
50
What can external morphology reveal about organisms?
It can determine many traits and linkages among closely related organisms.
51
What role does DNA play in classifying organisms?
Comparative studies of DNA provide a large number of characters for reconstructing phylogenies.
52
What is molecular systematics?
It is the use of DNA and proteins in the identification and classification of species.
53
What can molecular systematics help scientists do?
It allows scientists to refine previously identified evolutionary relationships and uncover evidence of new relationships.
54
What is DNA barcoding?
DNA barcoding is a method of identifying species based on the sequence of a standard section of DNA.
55
What gene is commonly used for DNA barcoding in animals?
A popular gene used for DNA barcoding in animals is the mitochondrial gene for cytochrome c oxidase subunit 1.
56
What role does cytochrome c oxidase play?
Cytochrome c oxidase plays a role in oxidative phosphorylation.
57
What is oxidative phosphorylation?
Oxidative phosphorylation is the process of releasing ATP in the electron transport chain process.
58
What does sequencing genes reveal?
Sequencing genes reveals small variations among individuals within a species but much more variation between individuals of different species.
59
How are gene sequences of closely related species compared to distantly related species?
The gene sequences of closely related species are more alike than those of more distantly related species.
60
What can DNA barcoding techniques sort out?
These techniques can be used to sort out how the sequence of a gene has changed over time.
61
What types of samples are used for DNA barcoding?
Blood or other tissues are sampled for DNA barcoding.
62
Can DNA barcoding be performed on living species?
Yes, DNA barcoding can be performed on living species in the wild or in captivity, and with preserved specimens in museums or laboratories.
63
What happens after DNA is purified and sequenced?
After purifying and sequencing DNA from the sample, the genetic sequences are reassembled using a computer.
64
How is genetic data compared in DNA barcoding?
The data can be compared against other samples or records in public databases by aligning the sequence to find areas of similarities.
65
What is morphology?
Morphology is the study of the form and structure of organisms or parts of organisms.
66
How were phylogenies constructed before modern DNA analysis?
Phylogenies were constructed using morphology.
67
Are trees derived from morphological characters accurate?
Yes, trees derived from morphological characters have been remarkably accurate.
68
Why is understanding morphology important?
Understanding morphology helps us make sense of evolutionary history.
69
What are cryptic species?
Cryptic species are species that appear identical to one another but are different at a genetic level and unable to breed with each other.
70
Can you give an example of cryptic species?
An example of cryptic species is African elephants that live in forests (Loxodonta cyclotis) and African elephants that live in the savanna (Loxodonta africana).
71
What role does DNA technology play in taxonomy?
DNA technology, when used in conjunction with other evidence and methods of evolutionary relationships, is an important tool for the field of taxonomy.
72
Who proposed the five-kingdom system?
R. H. Whittaker
73
In what year was the five-kingdom system proposed?
1969
74
What criteria were used to classify life in the five-kingdom system?
Cell type (eukaryotes vs. prokaryotes), food source, and mode of reproduction.
75
What kingdom contained all the prokaryotes?
Monera
76
What are the five kingdoms recognized in Whittaker's system?
1. Animalia
2. Plantae
3. Fungi
4. Protista
5. Monera
77
What does the kingdom Monera include?
All prokaryotic organisms
78
What revolutionized the classification of living things?
The availability of molecular data, particularly the sequencing of genes associated with ribosomal RNA.
79
Who pioneered the three-domain system?
Carl Woese and his team.
80
What are the three domains in the three-domain system?
Bacteria, Archaea, and Eukarya.
81
What does the domain Bacteria contain?
All true bacteria.
82
What characterizes Archaea?
Large groups of prokaryotes that differ from bacteria in the structure of their membranes and ribosomes.
83
What does the domain Eukarya contain?
All eukaryotic organisms, including plants, animals, fungi, and others.
84
How are plants, animals, and fungi classified in the three-domain system?
They are recognized as kingdoms within the domain Eukarya.
85
Is the kingdom Protista considered valid in the three-domain system?
No, the kingdom Protista is considered invalid.
86
What is often used as a catch-all classification for single-celled eukaryotic organisms?
'Protists' is still often used as a catch-all classification.
87
What is another name for bacteria?
Bacteria is also called Eubacteria, meaning 'true bacteria.'
88
What type of organisms are bacteria?
Bacteria are prokaryotic organisms.
89
What roles do bacteria play in the ecosystem?
Bacteria play critical roles in cycling carbon, nitrogen, and sulfur.
90
What is the relationship between bacteria and other organisms?
Bacteria have an important symbiotic relationship with other organisms.
91
What are the two types of bacteria based on nutrition?
Bacteria can be autotrophs or heterotrophs.
92
How do autotrophs obtain their food?
Autotrophs produce their own food from their surroundings using light energy in photosynthesis or chemical energy in chemosynthesis.
93
How do heterotrophs obtain their food?
Heterotrophs cannot produce their own food, so they ingest other organisms for nutrition.
94
What are the five bacterial phyla?
The five bacterial phyla are: 1. Chlamydias 2. Proteobacteria 3. Cyanobacteria 4. Spirochetes 5. Gram-positive bacteria (streptococcus, staphylococcus, Clostridium, listeria)
95
How can bacteria be categorized based on morphology?
Bacteria can be categorized by shape: Rod-shaped bacteria are bacillus, ball-shaped bacteria are coccus, and spiral-shaped bacteria are spirillum.
96
What is an example of a genus name that incorporates bacterial shape?
Examples include the genus name Streptococcus (coccus) and Lactobacillus (bacillus).
97
What are the two major groups of bacteria?
Gram-positive and gram-negative bacteria.
98
What characterizes gram-positive bacteria?
They have a thick, complex outer cell wall, mostly made of peptidoglycan, that stains a characteristic purple color after Gram staining.
99
What characterizes gram-negative bacteria?
They have a thinner layer of peptidoglycan in their cell wall and stain pink in Gram staining.
100
How are bacteria often categorized?
Bacteria are often categorized into five phyla, though this is debated.
101
Why is gram staining clinically important?
It is important for identifying the type of bacteria and appropriate treatment, such as prescribing antibiotics.
102
Why is it necessary to determine an infection's cause?
Bacteria can respond differently to antibiotics.
103
What is a bacterial culture test?
Cells from the sample for the Gram stain are smeared on a Petri dish with growth medium to identify the bacteria.
104
What happens after a few days of a bacterial culture test?
Laboratory personnel can examine the bacteria for identification.
105
What are Archaea?
Archaea is a diverse group of prokaryotic microorganisms that lack membrane-bound organelles and a nuclear envelope.
106
How do Archaea differ from bacteria?
Unlike bacteria, Archaea do not have peptidoglycan in their cell walls, have a different cell membrane structure, some genes have introns, and they differ in DNA replication and gene expression.
107
Where are Archaea commonly found?
Archaea are well known for living in extreme or inhospitable environments, such as hot springs, deep oceans under high pressure, freezing glaciers, and extremely acidic or basic environments.
108
What is the euryarchaeota?
The euryarchaeota includes methanogens that live in anaerobic conditions and metabolize hydrogen and carbon dioxide into methane gas.
109
Where can methanogens be found?
Methanogens can be found in swamps or animal intestines.
110
What are halobacteria?
Halobacteria are halophiles that live in very salty environments, such as the Great Salt Lake in Utah.
111
What does the phylum crenarchaeota include?
The phylum crenarchaeota includes many thermophiles that live in extremely high temperatures of 60 to 80 degrees Celsius.
112
What are some characteristics of certain crenarchaeota?
Some crenarchaeota are sulfur-based autotrophs.
113
What is the only species in the phylum nanoarchaeota?
The only species in the phylum nanoarchaeota is Nanoarchaeum equitans.
114
Where has Nanoarchaeum equitans been identified?
Nanoarchaeum equitans has been identified in a hydrothermal vent at Yellowstone National Park and at the bottom of the Atlantic Ocean.
115
What are korarchaeota?
Korarchaeota are thought to be one of the most primitive types of organisms.
116
Where have korarchaeota been found?
Korarchaeota have been found only in hot springs at Yellowstone National Park and in deep-sea vents.
117
What is the definition of protists?
The definition of protists is often debated by scientists.
118
What type of organisms are protists?
Protists are diverse eukaryotes that are mostly unicellular and relatively less complex than most other eukaryotes.
119
What cellular structures do protists possess?
Protists possess a nucleus and specialized organelles like mitochondria, Golgi apparatus, and plastids.
120
What is the scientific name for the kingdom of protists?
The scientific name 'Protista' is written in quotation marks because this group is paraphyletic.
121
How have protists traditionally been defined?
Historically, protists have been defined as any eukaryote that isn’t an animal, plant, or fungus.
122
How were protists traditionally classified?
Protists were traditionally classified by their morphology.
123
What are the nutritional modes of protists?
Protists can be autotrophic, heterotrophic, or saprotrophic, acquiring dissolved nutrients from their surroundings.
124
What are the main groups of organisms classified as plants?
Plants include red and green algae, bryophytes, and vascular plants.
125
What type of cells are plants made of?
Plants are multicellular and photosynthetic.
126
How do plants reproduce?
Plants can reproduce sexually or asexually.
127
What organelles do plants use for photosynthesis?
Plants carry out photosynthesis using organelles called chloroplasts.
128
What is the origin of chloroplasts in plants?
Chloroplasts evolved from symbiotic cyanobacteria.
129
Why are plants critical for human life?
Humans depend on the oxygen generated and the carbon-containing compounds produced by plants.
130
What adaptations have some plants evolved for nutrient-poor environments?
Some plants have evolved adaptations to nutrient-poor environments, especially in areas with low nitrogen availability.
131
What are examples of carnivorous plants?
Examples include pitcher plants and Venus flytraps.
132
How do carnivorous plants obtain nutrients?
Carnivorous plants obtain some of their nutrients by trapping and digesting insects and other small organisms.
133
What are fungi?
Fungi are a diverse group of eukaryotes that include both unicellular and multicellular organisms.
134
How do fungi reproduce?
Fungi can reproduce sexually or asexually.
135
What are the characteristics of fungi?
Fungi are non-vascular, non-moving, and heterotrophic, and possess a cell wall composed of chitin.
136
To which group are fungi more closely related?
Fungi are more closely related to animals than to plants.
137
What role do beneficial fungi play in the ecosystem?
Beneficial fungi are essential in the breakdown of dead matter.
138
What would happen without fungi?
Without fungi, many materials wouldn't be able to decompose.
139
What are some effects of certain types of fungi?
Some types of fungi cause disease, while others produce chemicals like antibiotics that help prevent the spread of pathogenic bacteria.
140
What are some uses of fungi by humans?
Mushrooms and yeast are eaten by humans and used to make beer and bread.
141
What are the four traditional groups of fungi?
Ascomycota (sac fungi), Basidiomycota (club fungi), Chytridiomycota (chytrids), and Zygomycota (zygomycetes)
## Footnote
These groups were traditionally used for classification.
142
What are chytrids and zygomycetes also known as?
Lower fungi
## Footnote
They are not monophyletic.
143
What did mycologists do in 2007?
They updated the taxonomy of fungi and described seven monophyletic groups.
144
What is Microsporidia?
Previously considered protists, now understood to be fungi.
145
Which groups were previously classified as chytrids?
Blastocladiomycota, Neocallimastigomycota, and Chytridiomycota.
146
What is Glomeromycota?
Soil fungi that have mutualistic relationships with plants.
147
What are Basidiomycota and Ascomycota often called?
Dikarya, or higher fungi.
148
What are the characteristics of animals?
Animals are multi-cellular heterotrophs, organized into tissues (except for sponges), and lack cell walls.
149
What types of tissue do animals possess?
Animals possess muscle tissue and nervous tissue that allow for active movement.
150
How do most animals reproduce?
Most animals reproduce sexually, but there are also many asexually-reproducing animals.
151
What is unique about animal embryonic development?
Animals undergo a unique type of embryonic development where a zygote undergoes cleavages to produce a blastula, followed by the formation of a gastrula.
152
How many recognized animal phyla are there?
There are about 35 recognized animal phyla.
153
What is the most diverse animal phylum?
The most diverse animal phylum is Arthropoda, containing more than 1,000,000 species.
154
Which phylum contains vertebrate animals?
The phylum Chordata contains vertebrate animals and accounts for about 56,000 species.
155
What is the second-most diverse group of animals?
Mollusks are the second-most diverse group, consisting of about 110,000 species.
156
What is the smallest animal phylum?
The smallest animal phylum is Micrognathoza, which contains only a single species discovered in 1994.
