1.1-1.5, Diversity of Living Things Flashcards
(137 cards)
1
Q
What is biodiversity?
A
The variety of life on Earth.
2
Q
How many described and classified species are there?
A
Over 1.2 million.
3
Q
What does biodiversity include?
A
Every living thing, from single-celled organisms to multicellular organisms.
4
Q
What is taxonomy?
A
Different ways of organizing and classifying life in ecosystems.
5
Q
Define biological species concept.
A
Grouping organisms as a species if they can successfully interbreed and produce fertile offspring.
6
Q
Why are labradors and poodles considered the same species?
A
They can reproduce and produce fertile offspring (labradoodles).
7
Q
What is a zorse?
A
A hybrid offspring of a horse and zebra that is infertile.
8
Q
Why are horses and zebras not considered the same species?
A
Their hybrid offspring (zorses) are not fertile.
9
Q
What issue arises with organisms that reproduce asexually regarding species classification?
A
The biological species definition becomes tenuous.
10
Q
What is the morphological species concept?
A
Classification of species based on structural and physical features.
11
Q
What is the phylogenetic species concept?
A
Classifies species based on common ancestry using tools like DNA analysis.
12
Q
What is genetic diversity?
A
The variety of genes among organisms within the same species.
13
Q
Define species interactions.
A
Organisms relying on another species for an increased rate of survival.
14
Q
What is species diversity?
A
The number of each species and the variety of different species in an ecosystem.
15
Q
What are autotrophs?
A
Organisms that are able to produce their own food (e.g. plants).
16
Q
What are heterotrophs?
A
Organisms that feed on other living or dead organisms (e.g. humans).
17
Q
Provide an example of protection in species interactions.
A
Clownfish use sea anemones for protection due to their immunity to toxins.
18
Q
Describe an example of transportation in species interactions.
A
Barnacles living on a whale are otherwise immotile.
19
Q
What is an example of reproduction in species interactions?
A
Many plants require other organisms to help spread their pollen.
20
Q
Explain the role of hygiene in species interactions.
A
Pilot fish eat scraps from sharks’ teeth.
21
Q
What is the role of digestion in species interactions?
A
Bacteria in the rumen of ruminants help break down grass.
22
Q
Define ecological diversity.
A
The variation in terrestrial/aquatic ecosystems and complexity of biological communities.
23
Q
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A
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24
Q
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25
What is taxonomy?
The science of naming, describing and classifying all living organisms based on shared characteristics.
26
Who is considered one of the earliest contributors to the classification of living organisms?
Aristotle and his student Theophrastus.
27
What two categories did Aristotle and Theophrastus divide all life into?
* Animals
* Plants
28
Who was Al-Jahiz and what did he write?
An Arab scholar who wrote The Book of Animals, examining classification of animals, food chains, and natural selection.
29
Which taxonomist formalized a more complex system for classifying living organisms?
Carl Linnaeus.
30
What is the basis of Linnaeus’ classification system?
Morphological traits (i.e. physical characteristics like shape, size, and colour).
31
What can be misleading about using morphology for classification?
There may be great physical variance within a species or little visible difference between two different species.
32
Give an example of species with distinct morphological traits.
* Mallard ducks
* Peacocks
33
What are the levels of classification in Linnaeus's system?
* Kingdom
* Phylum
* Class
* Order
* Family
* Genus
* Species
34
What is binomial nomenclature?
A system of naming organisms using the genus and species.
35
In binomial nomenclature, how is the genus and species formatted?
Genus is capitalized, species is not capitalized, and the full name is written in italics.
36
What is a tool created to identify organisms based on two defining statements?
A dichotomous key.
37
True or False: Horseshoe crabs are more closely related to true crabs than to spiders.
False.
38
How can seasonal changes affect classification in plants?
Organisms like plants can change significantly by season.
39
What is a taxon?
A group into which classified organisms are sorted.
40
What can cause difficulties in observing internal structures of species?
They may be similar but are difficult to observe.
41
What is the modified version of Linnaeus’ Systema Naturae?
A classification system that has evolved as more information is gathered.
42
Fill in the blank: The eastern and western meadowlarks are of a different species because they have distinct _______.
[songs].
43
What is traditional taxonomic classification based on?
The most obvious similarities between species
## Footnote
It generally uses visible characteristics, called morphology.
44
What is phylogenetics?
The study of the evolutionary relatedness between species using genetic information
45
What does phylogenetics allow us to understand?
What species share the most recent common ancestors, even if they look very different
46
What is a phylogeny?
A visual representation of the evolutionary relationships among a group of organisms
47
What supports the relationships represented in phylogenetic trees?
Scientific evidence, like genetic and biochemical data, and often includes a timeline
48
What are cladograms?
Similar to phylogenetic trees, but generally more simple and don’t include a timeline
49
What is the purpose of a cladogram?
To show relationships between a series of related organisms based on their shared traits
50
What is a clade?
A branch of a cladogram that represents all of the organisms that share a single common ancestor
51
What is an example of a characteristic shared by animals in a cladogram of vertebrates?
All animals share a backbone
52
What are some drawbacks of traditional taxonomy?
* Dichotomous keys may be ambiguous or subjective
* Following a dichotomous key takes time
* External morphological features can lead to incorrect classification
53
What is a potential issue with traditional taxonomy regarding genetic structures?
Different genetic structures may lead to similar physical structures
54
What is the limitation of using physical features in determining evolutionary relatedness?
Evolutionary relatedness is only a guess using physical features
55
How can DNA samples improve classification accuracy?
By collecting and comparing DNA samples of specimens, their identity and evolutionary relatedness can be determined efficiently and accurately
56
Why is modern taxonomy important?
* Organism research can be applied to other similar organisms
* Transmission and vulnerability to disease can be traced more easily
* Crop yield and disease resistance can be improved in plants by crossing certain species
57
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58
What is cell theory?
A universally accepted biological theory defining the concept of life.
59
What is the first principle of cell theory?
All living things are made up of one or more cells and their products.
60
What does the second principle of cell theory state?
The cell is the simplest unit that can carry out all life processes.
61
What is the third principle of cell theory?
All cells come from other cells; they do not come from nonliving matter.
62
List the seven characteristics of life.
* Nutrition
* Respiration
* Movement
* Excretion
* Growth
* Reproduction
* Sensitivity
63
What is the function of nutrition in living organisms?
Take in material (i.e. food) for growth.
64
What does respiration do in living organisms?
Release energy from food for cellular processes.
65
Define movement in the context of living organisms.
Move using energy consumed by the organism.
66
What is excretion?
Release waste products from cellular processes.
67
What does growth refer to in living organisms?
Use food to grow in size and/or number of cells.
68
What is reproduction in living organisms?
Produce offspring.
69
What does sensitivity mean in the context of life?
Sense and respond to stimuli in the environment.
70
What are viruses?
Microscopic particles capable of reproducing only within existing living cells (host cells).
71
What does the term 'virus' originate from?
Latin, meaning poison or toxin.
72
Why are viruses classified as non-living particles?
Cannot perform any of the processes that are the required characteristics of life.
73
What do viruses share with living organisms?
They contain genetic material (e.g. DNA) that can be passed on.
74
What do all viruses contain?
* Genetic material (DNA or RNA)
* A capsid (protective protein coat)
* An outer envelope containing surface proteins
75
Give an example of a helical virus.
Tobacco mosaic virus, Ebola.
76
What is an example of a polyhedral virus?
Adenoviruses (pink eye, common cold, viral pneumonia).
77
Name an example of a spherical virus.
Coronavirus, Influenza.
78
What are complex viruses?
Viruses that invade and destroy bacteria cells, e.g., Bacteriophages.
79
What are bacteriophages?
Viruses that invade & destroy bacteria cells.
80
What are the theories regarding the origin of viruses?
* Parasitic living organism that lost its ability to reproduce outside of another living cell.
* Produced from fragments of genetic material of an already-living organism.
* Virus-like particles existed before the first cells.
81
What are the two different ways that viruses can replicate within a host cell?
* The lytic cycle
* The lysogenic cycle
82
What happens during the lytic cycle?
The virus hijacks the host cell’s molecular machinery to reproduce itself.
83
What is the duration for the lytic cycle to produce new viruses?
As little as 40 minutes to produce 100 new viruses.
84
What occurs to the host cell during the lytic cycle?
The host cell is destroyed and releases new viruses to infect surrounding cells.
85
What occurs during the lysogenic cycle?
The virus incorporates its genetic material into the host cell’s genome, and the host cell remains intact.
86
What can trigger viral DNA to become active in the lysogenic cycle?
When triggered, the viral DNA becomes active and the virus enters the lytic cycle.
87
Provide an example of a virus that undergoes the lysogenic cycle.
Herpes virus (cold sores), HPV (genital warts).
88
How can viruses be transmitted?
* Bite by infected organisms
* Exchange of bodily fluids (e.g. blood, saliva, semen)
* Airborne via respiratory systems
* Physical contact with infected host or fomites
89
Are most viruses host-specific?
Yes, most viruses are selective and host-specific.
90
What is an example of a virus with a broad host range?
H1N1 (swine flu) - hogs & humans.
91
Can viruses be treated with antibiotics?
No, viruses cannot be treated with antibiotics.
92
What do vaccines contain?
* Weakened (attenuated) forms of a virus
* Dead forms of a virus
* Genetic material (RNA) from a virus
93
What is the role of white blood cells when given a vaccine?
Remember the virus so the immune system can react quickly when exposed to the real virus.
94
What roles does the World Health Organization (WHO) have regarding viruses?
* Monitoring viruses that pose public health threats
* Declaring epidemics and pandemics
* Helping countries prepare for outbreaks
* Supporting research and development tools for outbreaks
95
What is the Last Universal Common Ancestor (LUCA)?
The common ancestor of all three domains of life.
96
What are the main characteristics of bacteria?
Single-celled, prokaryotic organisms, most have cell walls made of peptidoglycan.
97
What is a pilus?
A structure used by bacteria to attach to surfaces and other cells.
98
What is the function of ribosomes in bacteria?
Performs protein synthesis.
99
Define nucleoid in the context of bacteria.
A densely packed loop of the bacterium’s DNA.
100
What is the role of a flagellum?
Used for motility (movement).
101
What is the composition of the bacterial cell wall?
Rigid peptidoglycan layer.
102
What does the plasma membrane do?
Controls what goes in and out of the cell.
103
What is a capsule in bacteria?
A thick, slimy protective outer layer.
104
What is a plasmid?
A loop of DNA containing several genes.
105
What is cytoplasm?
Fluid suspension containing the cell’s contents.
106
List the ways bacteria can be classified.
* Cell arrangement
* Cell shape
* Reaction to staining
* Metabolism
107
What does 'diplo-' indicate in bacterial arrangement?
Bacteria arranged in pairs.
108
What does 'strepto-' indicate in bacterial arrangement?
Bacteria arranged in chains.
109
What does 'staphylo-' indicate in bacterial arrangement?
Bacteria arranged in clumps.
110
What shape does 'coccus' refer to?
Round shape.
111
What shape does 'bacillus' refer to?
Rod shape.
112
What shape does 'spirillum' refer to?
Spiral shape.
113
What is the purpose of the Gram stain?
To identify bacteria based on cell wall characteristics.
114
What color do Gram-positive bacteria turn during Gram staining?
Purple.
115
What color do Gram-negative bacteria turn during Gram staining?
Pink.
116
Define metabolism in the context of bacteria.
The process by which organisms convert chemicals into energy.
117
What is a chemotroph?
An organism that obtains energy from inorganic molecules.
118
What is a heterotroph?
An organism that obtains energy from organic molecules produced by living organisms.
119
What is an autotroph?
An organism that obtains energy from performing photosynthesis.
120
What is an obligate aerobe?
An organism that requires oxygen to survive.
121
What is an obligate anaerobe?
An organism that will not survive in the presence of oxygen.
122
What is a facultative anaerobe?
An organism that can survive with or without oxygen but prefers oxygen.
123
Describe binary fission.
A method of asexual reproduction where a parent cell divides to produce two identical daughter cells.
124
How often can some bacteria double in population?
Every 20 minutes.
125
What is the significance of mutations in bacteria?
They increase genetic diversity within bacterial populations.
126
What is conjugation in bacteria?
A form of parasexual reproduction where one bacterium passes a plasmid to another.
127
Define transformation in bacteria.
When a bacterium picks up DNA from its surroundings and incorporates it into its own DNA.
128
What is an endospore?
A tough shell formed around a bacterium's nucleoid and some cytoplasm, allowing it to become dormant.
129
List some important uses of bacteria.
* Production of antibiotics
* Digestion (gut flora)
* Sewage treatment
* Production of fermented food
* Participation in biochemical cycles
130
What causes botulism?
Toxin produced by C. botulinum that paralyzes human muscles.
131
What is a common effect of E. coli?
Can cause diarrhea, cramps, or vomiting from contaminated food or water.
132
What is Chlamydia?
A common sexually transmitted infection (STI) caused by a parasitic bacterium.
133
What is the major difference between archaea and bacteria?
Archaea cell walls do not contain peptidoglycan.
134
What environments do methanogens thrive in?
Low-oxygen environments such as swamps and bogs.
135
What is the temperature range for thermophiles?
Hot places (70°C to 90°C).
136
What environments do halophiles inhabit?
Highly salinated places like salt flats and salt water.
137
What is an acidophile?
An organism that thrives in acidic environments (pH less than 2).
