Chapter 3: Classification and Biodiversity Flashcards
3.1 Classification
What is biodiversity and why is it important?
Biodiversity is the measure of variety in living organisms and their genetic differences. It helps monitor population changes and understand the relationships between organisms.
3.1 Classification
Why is classification necessary in biology?
Classification provides a standardized system for identifying organisms, tracking population changes, and understanding evolutionary relationships.
3.1 Classification
What are the main taxonomic groups from largest to smallest?
Domain, kingdom, phylum (division for plants), class, order, family, genus, species.
3.1 Classification
What are the two parts of a binomial name, and how are they written?
The genus (capitalized) and the species (lowercase), both written in italics, e.g., Homo sapiens.
3.1 Classification
What are the three domains into which all living organisms are classified?
Archaea, Bacteria, and Eukaryota.
3.1 Classification
What is the only kingdom in the Archaea domain, and what are its characteristics?
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.
3.1 Classification
What is the only kingdom in the Bacteria domain, and what are its characteristics?
Eubacteria – True bacteria that include disease-causing species and beneficial bacteria aiding digestion and nutrient recycling.
3.1 Classification
What are the four eukaryotic kingdoms?
Protactista, Fungi, Plantae, and Animalia.
3.1 Classification
What are the characteristics of Protactista?
A diverse group of microscopic organisms, including heterotrophs and autotrophs. Examples: Amoeba, Chlamydomonas, green and brown algae, and slime molds.
3.1 Classification
What are the characteristics of Fungi?
All heterotrophs, mostly saprophytic with some parasitic species, containing chitin (not cellulose) in their cell walls.
3.1 Classification
What are the characteristics of Plantae?
Mostly autotrophs, performing photosynthesis using chlorophyll. Examples: mosses, liverworts, ferns, gymnosperms, and angiosperms.
3.1 Classification
What are the two parts of a binomial name, and how are they written?
The genus (capitalized) and the species (lowercase), both written in italics, e.g., Homo sapiens.
3.1 Classification
Define species
A group of organisms with similar characteristics that interbreed to produce fertile offspring
3.1 Classification
Explain the limitations of defining a species.
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.
3.1 Classification
What are the advantages of the morphological species concept?
- Allows grouping based on observed characteristics.
- Useful when other data (e.g., genetic) is unavailable.
3.1 Classification
What are the limitations of the morphological species concept?
- Sexual dimorphism may lead to misclassification.
- Environmental factors can influence appearance.
- Similar-looking species may not be related.
3.1 Classification
What is the reproductive or biological species concept?
A species is defined as a group of organisms that interbreed to produce fertile offspring.
3.1 Classification
What are the advantages of the biological species concept?
- Addresses sexual dimorphism issues.
- Provides a practical approach for classifying animals.
3.1 Classification
What are the limitations of the biological species concept?
- 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.
3.1 Classification
What are the two more refined definitions under the biological species concept?
- A group of organisms that can potentially breed to produce fertile offspring.
- A group of organisms in which genes can flow between individuals.
3.1 Classification
What is the ecological species model?
Defines species based on the ecological niche they occupy.
3.1 Classification
What are the limitations of the ecological species model?
A species may occupy more than one niche.
3.1 Classification
What is the mate-recognition species model?
Defines species based on unique fertilization and mating behaviors.
3.1 Classification
What is a limitation of the mate-recognition species model?
Some species may interbreed with others but still remain distinct.
3.1 Classification
How does molecular biology contribute to species classification?
Uses DNA, RNA, and protein analysis to identify differences and relationships between species.
3.1 Classification
What is molecular phylogeny?
The study of evolutionary relationships using molecular data to classify species or the analysis of genetic material to determine evolutionary relationships.
.
3.1 Classification
What are potential issues with molecular phylogeny?
It may create overly complex classifications and misinterpret relationships.
3.1 Classification
What is the genetic species model?
A species definition based on DNA evidence.
3.1 Classification
What are the challenges of the genetic species model?
- 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.
3.1 Classification
What is the evolutionary species model?
A species definition based on shared evolutionary relationships and ongoing evolution.
3.1 Classification
What challenges are associated with the evolutionary species model?
Difficulties in identifying clear evolutionary pathways.
Not always easy to apply to organisms with limited evolutionary records.
3.1 Classification
Why is DNA analysis becoming more important in species classification?
It allows for more precise definitions and better understanding of evolutionary relationships.
3.1 Classification
Why is traditional morphology still used in species classification?
It remains useful for basic identification when genetic data is unavailable.
3.1 Classification
What is a challenge in classifying hybrids?
Determining at what point hybrids should be considered a separate species.
3.1 Classification
Why can’t reproduction-based models be used for all organisms?
Many organisms, such as bacteria, reproduce asexually, making reproductive criteria irrelevant.
3.1 Classification
Why is fossil classification challenging?
Fossils cannot reproduce or provide DNA, so classification relies on morphology alone.
3.1 Classification
What is sexual dimorphism?
A great deal of difference in appearance between male and female of the same species.
3.1 Classification
How can gel electrophoresis be used in classification?
Gel electrophoresis can be used to distinguish between species and determine evolutionary relationships by analyzing the DNA fragments of different organisms.
3.1 Classification
How does gel electrophoresis work?
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.
3.1 Classification
What are restriction enzymes used for in gel electrophoresis?
To cut DNA into fragments at specific sequences, creating pieces of different sizes for analysis.
3.1 Classification
What role does dye (e.g., ethidium bromide) play in gel electrophoresis?
It binds to DNA fragments, allowing them to be visualized under UV light.
3.1 Classification
What is the three-domain model of classification?
It divides life into Bacteria, Archaea, and Eukaryota, based on molecular and genetic differences.
3.1 Classification
How do Archaea differ from bacteria and eukaryotes?
Archaea share traits with both but are genetically distinct, often thriving in extreme environments.
3.1 Classification
What is a key biochemical similarity between echinoderms and vertebrates?
Both share similar ATP synthesis processes and embryological development, indicating a close evolutionary relationship.
3.1 Classification
What are two main blood pigments used by animals?
Hemoglobin (vertebrates) and hemocyanin (molluscs and arthropods).
3.1 Classification
Describe a detailed process of gel electrophoresis
- DNA is cut into fragments using restriction enzymes.
- Fragments are placed into gel wells with a buffer solution.
- An electric current is applied; DNA fragments move based on size.
- Smaller fragments move faster/farther than larger ones.
- Bands are visualized with a dye (e.g., ethidium bromide under UV light).
3.1 Classification
Describe how archea was introduced to the 3 domain system
- 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.
3.1 Classification
What role do scientific journals play in the scientific process?
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.
3.1 Classification
What are the five kingdoms in the five-kingdom classification system?
Monera (prokaryotes)
Protista (eukaryotic single-celled organisms)
Fungi (heterotrophic eukaryotes)
Plantae (autotrophic eukaryotes)
Animalia (heterotrophic multicellular eukaryotes).
3.1 Classification
What are extremophiles?
Bacteria that live in extreme environments, such as high heat, salinity, or acidity.
3.1 Classification
What are heterotrophs and autotrophs?
Organisms that cannot make their own food and must consume other organisms.(heterotroph)
Organisms that make their own food through photosynthesis or chemosynthesis.(autotroph)
3.1 Classification
What are key features of the Protista kingdom?
Protista-Includes single-celled eukaryotic organisms which mostly reproduce asexually.
3.1 Classification
What are the main characteristics of fungi?
Includes both unicellular and multicellular heterotrophic eukaryotes that reproduce sexually or asexually.
3.1 Classification
Define an endosymbiont.
An organism that lives inside the cells or body of another organism.
3.2 Natural selection
Define natural selection in the context of evolution.
Natural selection is the process by which evolution occurs through variation among organisms, leading to adaptations that enhance survival and reproduction.
3.2 Natural selection
How do organisms occupy niches?
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.
3.2 Natural selection
What is the significance of reproductive isolation in speciation?
Reproductive isolation can lead to allopatric and sympatric speciation by preventing different populations from interbreeding, allowing them to evolve into distinct species.
3.2 Natural selection
Describe the evolutionary race between pathogens and medicines.
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.
3.2 Natural selection
What are the key ideas behind Darwin’s theory of evolution?
- Living organisms reproduce sexually, showing genetic variation.
- Organisms produce excess offspring, but not all survive due to competition.
- Favorable traits give a survival and reproductive advantage.
- These traits are passed on, increasing their frequency in future generations.
- Traits reducing survival chances decrease in frequency.
3.2 Natural selection
What is the modern understanding of evolution?
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.
3.2 Natural selection
What are the three types of adaptations?
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).
3.2 Natural selection
How do behavioral adaptations improve survival?
By enabling organisms to manage environmental challenges, such as thermoregulation (e.g., lizards basking in the sun) or social behaviors (e.g., penguins huddling).
3.2 Natural selectionz
What is a successful species?
A species well-adapted to its niche, with traits that improve survival and reproduction, passed on to the next generation.
3.2 Natural selection
What processes can lead to genetic variation in populations?
Mutation, sexual reproduction, inbreeding, and hybridization.
3.2 Natural selection
What is the difference between natural selection and evolution?
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.
3.2 Natural selection
What is Neo-Darwinism?
An updated model of evolution that incorporates genetic and molecular biology advancements, highlighting the role of DNA in variation.
3.2 Natural selection
Why are niches important in evolution?
Niches define how species interact with their environment and other organisms, driving adaptations to improve survival in specific roles or habitats.
3.2 Natural selection
Define directional selection.
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.
3.2 Natural selection
How does directional selection affect the gene pool?
It increases the frequency of alleles that provide a survival or reproductive advantage within a population.
3.2 Natural selection
Define reproductive success.
Reproductive success is the ability of an organism to pass its genes to the next generation by producing offspring that survive and reproduce.
3.2 Natural selection
Why do some traits enhance reproductive success but not survival?
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.
3.2 Natural selection
How did bacteria develop resistance to penicillin, and therefore How does natural selection lead to antibiotic resistance?
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.
3.2 Natural selection
What are some factors that contribute to antibiotic resistance?
Overuse of antibiotics
Incorrect use of antibiotics (e.g., not completing the full course)
Widespread use of antibiotics in agriculture
Poor hygiene practices
3.2 Natural selection
What are the consequences of antibiotic resistance?
More difficult to treat infections, leading to increased illness and death
Development of new antibiotics becomes more challenging and expensive
3.2 Natural selection
What is speciation?
The formation of new species due to reproductive isolation.
3.2 Natural selection
What is the key factor in speciation?
Reproductive isolation, which prevents gene flow between populations.
3.2 Natural selection
What is allopatric speciation?
Speciation that occurs due to geographical separation of populations.
3.2 Natural selection
Give an example of allopatric speciation.
The evolution of Madagascar’s endemic species due to geographic isolation.
3.2 Natural selection
What is sympatric speciation?
Speciation that occurs within the same location due to reproductive isolation.
3.2 Natural selection
What is adaptive radiation?
When one species rapidly evolves into multiple species to fill different ecological niches.
3.2 Natural selection
Name five isolating mechanisms in speciation.
Geographical, ecological, seasonal, behavioural, and mechanical isolation.
3.2 Natural selection
What is hybridisation in speciation?
When two closely related species interbreed, sometimes forming fertile or sterile offspring.
3.2 Natural selection
Describe the five isolation mechanisms?
- Geographical isolation: Physical barriers (e.g., rivers, mountains).
- Ecological isolation: Species inhabit different parts of the same region.
- Seasonal isolation: Differences in mating seasons or flowering times.
- Behavioural isolation: Differences in courtship or mating patterns.
- Mechanical isolation: Physical incompatibility in reproductive structures.
3.3 Biodiversity
What formula can be used to calculate the level of biodiversity within a habitat?
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
3.3 Biodiversity
Why is maintaining biodiversity important?
For ethical and economic reasons, including ecosystem services.
3.3 Biodiversity
How is genetic biodiversity assessed?
By looking at the variety of alleles in the gene pool of a population.
3.3 Biodiversity
What are the principles of in-situ conservation?
In-situ conservation involves protecting habitats to maintain biodiversity in their natural environments.
3.3 Biodiversity
What are the principles of ex-situ conservation?
Ex-situ conservation involves measures like zoos and seed banks to preserve biodiversity outside of natural habitats.
3.3 Biodiversity
What are the issues surrounding in-situ and ex-situ conservation?
Challenges include ethical considerations, resource allocation, and ensuring long-term effectiveness for biodiversity maintenance.
3.3 Biodiversity
3.3 Biodiversity
3.3 Biodiversity
3.3 Biodiversity
3.3 Biodiversity
What is endemism?
Endemism refers to species that are unique to a specific geographic location and found nowhere else, often in biodiversity hotspots.
3.3 Biodiversity
Why are biodiversity hotspots important but vulnerable?
Biodiversity hotspots have high species richness and endemism but are often at risk of damage due to habitat loss, climate change, and human activity.
3.3 Biodiversity
What does species abundance refer to, and why is it important in biodiversity?
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.
3.3 Biodiversity
How does the diversity index reflect biodiversity in an area?
A higher diversity index value indicates a greater variety of organisms and a healthier, more balanced ecosystem.
3.3 Biodiversity
What factors contribute to high biodiversity in an area?
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.
3.3 Biodiversity
How do extreme environmental conditions affect biodiversity?
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.
3.3 Biodiversity
Why is biodiversity not constant throughout the year?
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).
3.3 Biodiversity
What is a biodiversity hotspot, and why is it significant?
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.
3.3 Biodiversity
How does species richness differ from relative species abundance?
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.
3.3 Biodiversity
How does biodiversity loss occur, and what are its implications?
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.
3.3 Biodiversity
What are mutations, and how can they affect an organism?
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.
3.3 Biodiversity
How do mutations impact the gene pool of a population?
Mutations increase the gene pool by introducing new alleles, which enhances genetic diversity and improves the population’s ability to adapt to environmental changes.
3.3 Biodiversity
What is allele frequency, and how is it affected by mutations?
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.
3.3 Biodiversity
How do natural selection and environmental shifts influence allele frequency?
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.
3.3 Biodiversity
What are neutral mutations, and how common are they?
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.
3.3 Biodiversity
What are the different types of ex-situ conservation?
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.
3.3 Biodiversity
What are the different types of in-situ conservation?
Education programmes: Teach importance of biodiversity and risks like illegal wildlife trade.
Protected areas: National Parks & Sites of Scientific Interest conserve habitats and biodiversity.
