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Biology > Chapter 3: Classification and Biodiversity > Flashcards

Chapter 3: Classification and Biodiversity Flashcards

1
Q

3.1 Classification

What is biodiversity and why is it important?

A

Biodiversity is the measure of variety in living organisms and their genetic differences. It helps monitor population changes and understand the relationships between organisms.

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2
Q

3.1 Classification

Why is classification necessary in biology?

A

Classification provides a standardized system for identifying organisms, tracking population changes, and understanding evolutionary relationships.

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3
Q

3.1 Classification

What are the main taxonomic groups from largest to smallest?

A

Domain, kingdom, phylum (division for plants), class, order, family, genus, species.

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4
Q

3.1 Classification

What are the two parts of a binomial name, and how are they written?

A

The genus (capitalized) and the species (lowercase), both written in italics, e.g., Homo sapiens.

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5
Q

3.1 Classification

What are the three domains into which all living organisms are classified?

A

Archaea, Bacteria, and Eukaryota.

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6
Q

3.1 Classification

What is the only kingdom in the Archaea domain, and what are its characteristics?

A

Archaebacteria – Ancient bacteria thought to be early relatives of eukaryotes, initially believed to exist only in extreme environments but now found everywhere, especially in soil.

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7
Q

3.1 Classification

What is the only kingdom in the Bacteria domain, and what are its characteristics?

A

Eubacteria – True bacteria that include disease-causing species and beneficial bacteria aiding digestion and nutrient recycling.

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8
Q

3.1 Classification

What are the four eukaryotic kingdoms?

A

Protactista, Fungi, Plantae, and Animalia.

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9
Q

3.1 Classification

What are the characteristics of Protactista?

A

A diverse group of microscopic organisms, including heterotrophs and autotrophs. Examples: Amoeba, Chlamydomonas, green and brown algae, and slime molds.

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10
Q

3.1 Classification

What are the characteristics of Fungi?

A

All heterotrophs, mostly saprophytic with some parasitic species, containing chitin (not cellulose) in their cell walls.

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11
Q

3.1 Classification

What are the characteristics of Plantae?

A

Mostly autotrophs, performing photosynthesis using chlorophyll. Examples: mosses, liverworts, ferns, gymnosperms, and angiosperms.

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12
Q

3.1 Classification

What are the two parts of a binomial name, and how are they written?

A

The genus (capitalized) and the species (lowercase), both written in italics, e.g., Homo sapiens.

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13
Q

3.1 Classification

Define species

A

A group of organisms with similar characteristics that interbreed to produce fertile offspring

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14
Q

3.1 Classification

Explain the limitations of defining a species.

A

The definition of a species as a group of organisms with similar characteristics that interbreed to produce fertile offspring has limitations, as it can be difficult to assign organisms to a single species or identify new species.

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15
Q

3.1 Classification

What are the advantages of the morphological species concept?

A
  • Allows grouping based on observed characteristics.
  • Useful when other data (e.g., genetic) is unavailable.
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16
Q

3.1 Classification

What are the limitations of the morphological species concept?

A
  • Sexual dimorphism may lead to misclassification.
  • Environmental factors can influence appearance.
  • Similar-looking species may not be related.
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17
Q

3.1 Classification

What is the reproductive or biological species concept?

A

A species is defined as a group of organisms that interbreed to produce fertile offspring.

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18
Q

3.1 Classification

What are the advantages of the biological species concept?

A
  • Addresses sexual dimorphism issues.
  • Provides a practical approach for classifying animals.
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19
Q

3.1 Classification

What are the limitations of the biological species concept?

A
  • Does not account for geographically separated populations.
  • Hybrids (e.g., mules) are sterile despite shared characteristics.
  • Less effective for plants that frequently interbreed with related species.
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20
Q

3.1 Classification

What are the two more refined definitions under the biological species concept?

A
  • A group of organisms that can potentially breed to produce fertile offspring.
  • A group of organisms in which genes can flow between individuals.
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21
Q

3.1 Classification

What is the ecological species model?

A

Defines species based on the ecological niche they occupy.

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22
Q

3.1 Classification

What are the limitations of the ecological species model?

A

A species may occupy more than one niche.

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23
Q

3.1 Classification

What is the mate-recognition species model?

A

Defines species based on unique fertilization and mating behaviors.

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24
Q

3.1 Classification

What is a limitation of the mate-recognition species model?

A

Some species may interbreed with others but still remain distinct.

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25
Q

3.1 Classification

How does molecular biology contribute to species classification?

A

Uses DNA, RNA, and protein analysis to identify differences and relationships between species.

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26
Q

3.1 Classification

What is molecular phylogeny?

A

The study of evolutionary relationships using molecular data to classify species or the analysis of genetic material to determine evolutionary relationships.

.

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27
Q

3.1 Classification

What are potential issues with molecular phylogeny?

A

It may create overly complex classifications and misinterpret relationships.

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28
Q

3.1 Classification

What is the genetic species model?

A

A species definition based on DNA evidence.

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29
Q

3.1 Classification

What are the challenges of the genetic species model?

A
  • Deciding how much genetic difference defines a species.
  • Historically, DNA collection was expensive and time-consuming.
  • Although now faster and cheaper, defining species still requires clear thresholds.
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30
Q

3.1 Classification

What is the evolutionary species model?

A

A species definition based on shared evolutionary relationships and ongoing evolution.

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31
Q

3.1 Classification

What challenges are associated with the evolutionary species model?

A

Difficulties in identifying clear evolutionary pathways.
Not always easy to apply to organisms with limited evolutionary records.

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32
Q

3.1 Classification

Why is DNA analysis becoming more important in species classification?

A

It allows for more precise definitions and better understanding of evolutionary relationships.

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33
Q

3.1 Classification

Why is traditional morphology still used in species classification?

A

It remains useful for basic identification when genetic data is unavailable.

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33
Q

3.1 Classification

What is a challenge in classifying hybrids?

A

Determining at what point hybrids should be considered a separate species.

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34
Q

3.1 Classification

Why can’t reproduction-based models be used for all organisms?

A

Many organisms, such as bacteria, reproduce asexually, making reproductive criteria irrelevant.

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35
Q

3.1 Classification

Why is fossil classification challenging?

A

Fossils cannot reproduce or provide DNA, so classification relies on morphology alone.

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36
Q

3.1 Classification

What is sexual dimorphism?

A

A great deal of difference in appearance between male and female of the same species.

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37
Q

3.1 Classification

How can gel electrophoresis be used in classification?

A

Gel electrophoresis can be used to distinguish between species and determine evolutionary relationships by analyzing the DNA fragments of different organisms.

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38
Q

3.1 Classification

How does gel electrophoresis work?

A

DNA fragments are placed in a gel, an electric current is applied, and smaller fragments of the DNA move faster and farther than larger ones, making it easy to distinguish the DNA of one individual from another.

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39
Q

3.1 Classification

What are restriction enzymes used for in gel electrophoresis?

A

To cut DNA into fragments at specific sequences, creating pieces of different sizes for analysis.

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40
Q

3.1 Classification

What role does dye (e.g., ethidium bromide) play in gel electrophoresis?

A

It binds to DNA fragments, allowing them to be visualized under UV light.

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41
Q

3.1 Classification

What is the three-domain model of classification?

A

It divides life into Bacteria, Archaea, and Eukaryota, based on molecular and genetic differences.

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42
Q

3.1 Classification

How do Archaea differ from bacteria and eukaryotes?

A

Archaea share traits with both but are genetically distinct, often thriving in extreme environments.

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43
Q

3.1 Classification

What is a key biochemical similarity between echinoderms and vertebrates?

A

Both share similar ATP synthesis processes and embryological development, indicating a close evolutionary relationship.

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44
Q

3.1 Classification

What are two main blood pigments used by animals?

A

Hemoglobin (vertebrates) and hemocyanin (molluscs and arthropods).

45
Q

3.1 Classification

Describe a detailed process of gel electrophoresis

A
  1. DNA is cut into fragments using restriction enzymes.
  2. Fragments are placed into gel wells with a buffer solution.
  3. An electric current is applied; DNA fragments move based on size.
  4. Smaller fragments move faster/farther than larger ones.
  5. Bands are visualized with a dye (e.g., ethidium bromide under UV light).
46
Q

3.1 Classification

Describe how archea was introduced to the 3 domain system

A
  • Early classification split organisms into two groups:
  • Eukaryotes (cells with a nucleus).
  • Prokaryotes (cells without a nucleus, e.g., bacteria).
  • The discovery of Archaea in the 1970s suggested a third domain:
  • Archaea share traits with both bacteria and eukaryotes.
  • Some believe mitochondria arose from bacterial endosymbionts.
47
Q

3.1 Classification

What role do scientific journals play in the scientific process?

A

Scientific journals, along with the peer review process and scientific conferences, play a crucial role in validating new evidence that supports the accepted scientific theory of evolution.

48
Q

3.1 Classification

What are the five kingdoms in the five-kingdom classification system?

A

Monera (prokaryotes)
Protista (eukaryotic single-celled organisms)
Fungi (heterotrophic eukaryotes)
Plantae (autotrophic eukaryotes)
Animalia (heterotrophic multicellular eukaryotes).

49
Q

3.1 Classification

What are extremophiles?

A

Bacteria that live in extreme environments, such as high heat, salinity, or acidity.

50
Q

3.1 Classification

What are heterotrophs and autotrophs?

A

Organisms that cannot make their own food and must consume other organisms.(heterotroph)
Organisms that make their own food through photosynthesis or chemosynthesis.(autotroph)

51
Q

3.1 Classification

What are key features of the Protista kingdom?

A

Protista-Includes single-celled eukaryotic organisms which mostly reproduce asexually.

52
Q

3.1 Classification

What are the main characteristics of fungi?

A

Includes both unicellular and multicellular heterotrophic eukaryotes that reproduce sexually or asexually.

53
Q

3.1 Classification

Define an endosymbiont.

A

An organism that lives inside the cells or body of another organism.

54
Q

3.2 Natural selection

Define natural selection in the context of evolution.

A

Natural selection is the process by which evolution occurs through variation among organisms, leading to adaptations that enhance survival and reproduction.

55
Q

3.2 Natural selection

How do organisms occupy niches?

A

Organisms occupy niches based on their physiological, behavioral, and anatomical adaptations that allow them to thrive in specific environments.

ALTERNATE defintion: The process by which organisms with traits better suited to their environment are more likely to survive and reproduce.

56
Q

3.2 Natural selection

What is the significance of reproductive isolation in speciation?

A

Reproductive isolation can lead to allopatric and sympatric speciation by preventing different populations from interbreeding, allowing them to evolve into distinct species.

57
Q

3.2 Natural selection

Describe the evolutionary race between pathogens and medicines.

A

There is an evolutionary race between pathogens and the development of medicines, as pathogens evolve to resist treatments while scientists work to create effective medicines.

58
Q

3.2 Natural selection

What are the key ideas behind Darwin’s theory of evolution?

A
  1. Living organisms reproduce sexually, showing genetic variation.
  2. Organisms produce excess offspring, but not all survive due to competition.
  3. Favorable traits give a survival and reproductive advantage.
  4. These traits are passed on, increasing their frequency in future generations.
  5. Traits reducing survival chances decrease in frequency.
59
Q

3.2 Natural selection

What is the modern understanding of evolution?

A

Evolution occurs due to differential survival and reproduction of organisms with different genotypes in a specific environment. Natural selection favors traits that improve survival or reproduction.

60
Q

3.2 Natural selection

What are the three types of adaptations?

A

Physiological Adaptations: Internal body functions aiding survival (e.g., mammalian diving response).
Behavioral Adaptations: Instinctive or learned behaviors increasing survival (e.g., penguins huddling for warmth).
Anatomical Adaptations: Physical structures enhancing survival (e.g., sticky hairs on sundew plants trapping insects).

61
Q

3.2 Natural selection

How do behavioral adaptations improve survival?

A

By enabling organisms to manage environmental challenges, such as thermoregulation (e.g., lizards basking in the sun) or social behaviors (e.g., penguins huddling).

62
Q

3.2 Natural selectionz

What is a successful species?

A

A species well-adapted to its niche, with traits that improve survival and reproduction, passed on to the next generation.

63
Q

3.2 Natural selection

What processes can lead to genetic variation in populations?

A

Mutation, sexual reproduction, inbreeding, and hybridization.

64
Q

3.2 Natural selection

What is the difference between natural selection and evolution?

A

Natural selection is the process of survival and reproduction of the fittest, while evolution is the long-term result of this process, leading to changes in populations.

65
Q

3.2 Natural selection

What is Neo-Darwinism?

A

An updated model of evolution that incorporates genetic and molecular biology advancements, highlighting the role of DNA in variation.

66
Q

3.2 Natural selection

Why are niches important in evolution?

A

Niches define how species interact with their environment and other organisms, driving adaptations to improve survival in specific roles or habitats.

67
Q

3.2 Natural selection

Define directional selection.

A

Directional selection is a type of natural selection that favors one extreme phenotype, leading to a shift in a population’s traits over time in response to environmental pressures.

68
Q

3.2 Natural selection

How does directional selection affect the gene pool?

A

It increases the frequency of alleles that provide a survival or reproductive advantage within a population.

69
Q

3.2 Natural selection

Define reproductive success.

A

Reproductive success is the ability of an organism to pass its genes to the next generation by producing offspring that survive and reproduce.

70
Q

3.2 Natural selection

Why do some traits enhance reproductive success but not survival?

A

Traits like long tails in widow birds or bee-like flowers in orchids are adaptations that make organisms more attractive to mates or pollinators, boosting reproduction without necessarily improving survival.

71
Q

3.2 Natural selection

How did bacteria develop resistance to penicillin, and therefore How does natural selection lead to antibiotic resistance?

A

Random mutations allowed some bacteria to produce enzymes that deactivated penicillin. These resistant bacteria survived and reproduced. Antibiotics kill non-resistant bacteria, allowing resistant strains to survive, reproduce, and dominate bacterial populations.

72
Q

3.2 Natural selection

What are some factors that contribute to antibiotic resistance?

A

Overuse of antibiotics
Incorrect use of antibiotics (e.g., not completing the full course)
Widespread use of antibiotics in agriculture
Poor hygiene practices

73
Q

3.2 Natural selection

What are the consequences of antibiotic resistance?

A

More difficult to treat infections, leading to increased illness and death
Development of new antibiotics becomes more challenging and expensive

74
Q

3.2 Natural selection

What is speciation?

A

The formation of new species due to reproductive isolation.

75
Q

3.2 Natural selection

What is the key factor in speciation?

A

Reproductive isolation, which prevents gene flow between populations.

76
Q

3.2 Natural selection

What is allopatric speciation?

A

Speciation that occurs due to geographical separation of populations.

77
Q

3.2 Natural selection

Give an example of allopatric speciation.

A

The evolution of Madagascar’s endemic species due to geographic isolation.

78
Q

3.2 Natural selection

What is sympatric speciation?

A

Speciation that occurs within the same location due to reproductive isolation.

79
Q

3.2 Natural selection

What is adaptive radiation?

A

When one species rapidly evolves into multiple species to fill different ecological niches.

80
Q

3.2 Natural selection

Name five isolating mechanisms in speciation.

A

Geographical, ecological, seasonal, behavioural, and mechanical isolation.

81
Q

3.2 Natural selection

What is hybridisation in speciation?

A

When two closely related species interbreed, sometimes forming fertile or sterile offspring.

82
Q

3.2 Natural selection

Describe the five isolation mechanisms?

A
  1. Geographical isolation: Physical barriers (e.g., rivers, mountains).
  2. Ecological isolation: Species inhabit different parts of the same region.
  3. Seasonal isolation: Differences in mating seasons or flowering times.
  4. Behavioural isolation: Differences in courtship or mating patterns.
  5. Mechanical isolation: Physical incompatibility in reproductive structures.
83
Q

3.3 Biodiversity

What formula can be used to calculate the level of biodiversity within a habitat?

A

D = N(N-1) / Σn(n-1)

Where:

D = Index of diversity
N = Total number of organisms of all species
n = Total number of organisms of each1 individual species

84
Q

3.3 Biodiversity

Why is maintaining biodiversity important?

A

For ethical and economic reasons, including ecosystem services.

85
Q

3.3 Biodiversity

How is genetic biodiversity assessed?

A

By looking at the variety of alleles in the gene pool of a population.

86
Q

3.3 Biodiversity

What are the principles of in-situ conservation?

A

In-situ conservation involves protecting habitats to maintain biodiversity in their natural environments.

87
Q

3.3 Biodiversity

What are the principles of ex-situ conservation?

A

Ex-situ conservation involves measures like zoos and seed banks to preserve biodiversity outside of natural habitats.

88
Q

3.3 Biodiversity

What are the issues surrounding in-situ and ex-situ conservation?

A

Challenges include ethical considerations, resource allocation, and ensuring long-term effectiveness for biodiversity maintenance.

89
Q

3.3 Biodiversity

A
90
Q

3.3 Biodiversity

A
91
Q

3.3 Biodiversity

A
92
Q

3.3 Biodiversity

A
93
Q

3.3 Biodiversity

What is endemism?

A

Endemism refers to species that are unique to a specific geographic location and found nowhere else, often in biodiversity hotspots.

94
Q

3.3 Biodiversity

Why are biodiversity hotspots important but vulnerable?

A

Biodiversity hotspots have high species richness and endemism but are often at risk of damage due to habitat loss, climate change, and human activity.

95
Q

3.3 Biodiversity

What does species abundance refer to, and why is it important in biodiversity?

A

Species abundance is the relative proportion of different species in an area. Even distribution of species increases biodiversity, compared to dominance by a few species.

96
Q

3.3 Biodiversity

How does the diversity index reflect biodiversity in an area?

A

A higher diversity index value indicates a greater variety of organisms and a healthier, more balanced ecosystem.

97
Q

3.3 Biodiversity

What factors contribute to high biodiversity in an area?

A

High biodiversity is typically seen in:
* Very stable ecosystems, which allow complex relationships between species.
* Areas with high productivity (e.g., high photosynthesis rates), supporting more niches.
* Areas where organisms grow and reproduce rapidly, increasing mutations and adaptations.

98
Q

3.3 Biodiversity

How do extreme environmental conditions affect biodiversity?

A

Extreme environments tend to have low biodiversity because:
* They are unstable and susceptible to rapid changes.
* A single event (e.g., flood or disease) can devastate populations.
* Few organisms are adapted to survive in such conditions.

99
Q

3.3 Biodiversity

Why is biodiversity not constant throughout the year?

A

Biodiversity can change due to:

Seasonal migration of species.
Temperature and environmental shifts affecting species presence.
Different habitats being active at varying times (e.g., wetlands in winter vs. summer).

100
Q

3.3 Biodiversity

What is a biodiversity hotspot, and why is it significant?

A

A biodiversity hotspot is an area with exceptionally high species richness and endemism. These areas are highly vulnerable to damage and loss, making them critical for conservation.

101
Q

3.3 Biodiversity

How does species richness differ from relative species abundance?

A

Species richness refers to the number of different species in an area.
Relative species abundance is the proportion of individuals of each species relative to the total population.

102
Q

3.3 Biodiversity

How does biodiversity loss occur, and what are its implications?

A

Biodiversity loss can result from:

Natural events (e.g., volcanoes, flooding).
Human activities (e.g., habitat destruction, pollution).
Implications:
Loss of ecosystem stability and services.
Decrease in the gene pool and extinction of species.

103
Q

3.3 Biodiversity

What are mutations, and how can they affect an organism?

A

Mutations are changes in DNA structure, ranging from small (e.g., a single base pair) to large (e.g., loss or duplication of a chromosome). Their effects vary:
* No effect on phenotype (neutral).
* Severe or lethal effects.
* Advantageous effects that improve survival.

104
Q

3.3 Biodiversity

How do mutations impact the gene pool of a population?

A

Mutations increase the gene pool by introducing new alleles, which enhances genetic diversity and improves the population’s ability to adapt to environmental changes.

105
Q

3.3 Biodiversity

What is allele frequency, and how is it affected by mutations?

A

Allele frequency is the relative proportion of a specific allele in a population.

  • Advantageous mutations increase in frequency due to natural selection.
  • Disadvantageous mutations are often removed unless they provide some benefit in changing conditions.
106
Q

3.3 Biodiversity

How do natural selection and environmental shifts influence allele frequency?

A

Natural selection drives changes in allele frequency, favoring beneficial traits and potentially leading to new species.
Environmental changes can make previously disadvantageous alleles beneficial, increasing their frequency.

107
Q

3.3 Biodiversity

What are neutral mutations, and how common are they?

A

Neutral mutations neither help nor harm the organism and do not affect the phenotype. They are common, with an average baby inheriting around 100 new neutral mutations.

108
Q

3.3 Biodiversity

What are the different types of ex-situ conservation?

A

Captive breeding programmes: Increase population & genetic diversity using techniques like IVF, stud books, and gamete exchange.
Reintroduction programmes: Release captive-bred animals to restore habitats.
Seed banks:
Store seeds to conserve genetic diversity and prevent extinction.
Advantages: Conserves many species, takes less space, and is cheaper than storing plants.
Seeds stored in cool, dry conditions & periodically tested for viability.

109
Q

3.3 Biodiversity

What are the different types of in-situ conservation?

A

Education programmes: Teach importance of biodiversity and risks like illegal wildlife trade.
Protected areas: National Parks & Sites of Scientific Interest conserve habitats and biodiversity.

Biology (9 decks)

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