Introduction to Biodiversity - BIO153 Diversity of Organisms

These flashcards are designed to help students review key concepts and terminology from the Introduction to Biodiversity lecture.

What does biodiversity mean?

The variety of life in the world or in a particular habitat or ecosystem.

What is LUCA?

The last universal common ancestor of all cellular life on Earth.

How long ago did LUCA exist?

About 4 billion years ago.

What is the result of billions of years of evolution?

Diverse forms of life through natural selection.

What is a polytomy in a phylogenetic tree?

A branch point leading to multiple lineages.

Which domain of life do bacteria belong to?

Domain Bacteria.

What distinguishes archaea from bacteria?

Many archaea live in extreme environments.

What type of organisms does Domain Eukarya include?

Organisms with eukaryotic cells, including plants, animals, fungi, and protists.

What is taxonomy?

The science of naming and classifying organisms.

Why is naming important in taxonomy?

To communicate unambiguously about organisms.

What are the three common domains of life?

Bacteria, Archaea, and Eukarya.

What is phylogeny?

The study of the evolutionary history and relationships among species.

What is the difference between an obligate and opportunistic pathogen?

Obligate pathogens cause disease consistently, while opportunistic pathogens only cause disease when the host's immune system is compromised.

What causes Lyme disease?

Borrelia burgdorferi, a spirochete bacterium.

Which organism is affected by the predator-prey relationship example given in the notes?

Snowshoe hare and Canada lynx.

What organisms are classified as chemoheterotrophs?

Organisms that obtain energy and carbon by consuming organic molecules.

What essential role do cyanobacteria play?

They perform photosynthesis and fix atmospheric nitrogen.

What is the significance of horizontal gene transfer?

It complicates the categorization and evolutionary relationships among organisms.

What is the binomial nomenclature?

A two-part naming system for organisms that includes the genus and species.

What does it mean if a classification is paraphyletic?

A group that includes a common ancestor but not all its descendants.

What can phylogenetic trees show?

The evolutionary relationships and divergence of species.

What is the purpose of a cladogram?

To illustrate the relationships based on shared characteristics.

Why is it important to understand morphological traits?

They help in determining evolutionary relationships among organisms.

What does 'analogy' refer to in biology?

Similar traits in organisms that arose independently, not from a common ancestor.

What characterizes homologous traits?

Similar traits in different species that originate from a common ancestor.

What is a basal taxon?

The lineage that diverged from all other members early in the evolution of the group.

What is the role of photosynthesis in the ecosystem?

It converts light energy into chemical energy stored in glucose.

What types of organisms are mainly photoautotrophs?

Plants, algae, and certain bacteria.

What is the function of peptidoglycan in bacterial cell walls?

To provide structure and support to the cell.

How do antibiotics affect bacteria?

They target bacterial cell wall components like peptidoglycan.

What process do aerobic organisms use to obtain energy?

Aerobic respiration, which uses oxygen to produce ATP.

What is the significance of genetic traits for classification?

They help determine the evolutionary relationships based on genetic similarities and differences.

What is the difference between obligate aerobes and obligate anaerobes?

Obligate aerobes require oxygen for survival, while obligate anaerobes cannot tolerate oxygen.

What is meant by convergent evolution?

The process where unrelated organisms independently evolve similar traits.

What are the main points of a phylogenetic tree?

They illustrate relationships between species and show common ancestry.

What is a dichotomy in a phylogenetic tree?

A branch point that divides into exactly two lineages.

What is the difference between a cladogram and phylogram?

Cladograms show relationships without information about time or genetic change, while phylograms include branch lengths indicating the amount of change.

What does the term 'sister taxa' refer to?

Groups of organisms that share an immediate common ancestor.

What is biofilm's role in pathogenesis?

It helps pathogens adhere to surfaces and evade host defenses.

Why can't some organisms be classified as mutualistic?

They may not provide consistent benefits and can harm the host instead.

What is a primary producer?

An organism that produces organic compounds from carbon dioxide through photosynthesis.

What is adaptive radiation?

The rapid evolution of diversely adapted species from a common ancestor.

What is meant by the term 'infectious disease'?

Any disease caused by a microorganism.

What factors influence the spread of epidemics?

Population density, human behavior, and genetic susceptibility.

What is the evolutionary significance of endosymbiosis?

It's a process that led to the formation of eukaryotic cells from prokaryotic ancestors.

How are prokaryotic cells categorized?

Into bacteria and archaea based on their cell structure and environmental adaptations.

What constitutes a healthy microbiome?

An ecosystem of beneficial microbes that aid in digestion and overall health.

What role do fungi play in ecosystems?

Decomposers that break down organic materials and recycle nutrients.

What defines harmful algae blooms?

Rapid increase in algae that can produce toxins harmful to aquatic life and humans.

What concept explains the varying classification systems among scientists?

Taxonomy is influenced by changing knowledge and evolutionary understanding.

What is a character table used for in cladistics?

To summarize shared traits among organisms to infer evolutionary relationships.

What environmental factors influence bacterial diversity?

Temperature, pH, salinity, and nutrients available in the environment.

What organism is known for the nitrogen fixation process?

Certain species of cyanobacteria.

Describe mutualism in symbiotic relationships.

Both species benefit from the interaction.

How do viruses differ from cellular organisms?

They are acellular, requiring a host to reproduce.

What is the significance of ribosomal RNA in evolution studies?

They mutate slowly and serve as a reliable molecular clock.

What is a significant threat to biodiversity?

Habitat destruction, pollution, climate change, and invasive species.

What is an example of a polyphyletic group?

Algae, which contains members from different evolutionary lineages.

What defines the term 'endemic species'?

Species that are native to and found only within a specific geographic area.

What does systemic risk refer to in ecological studies?

Risks that could affect entire ecosystems or biomes due to interlinked components.

What is the primary difference between phototrophs and chemotrophs?

Phototrophs obtain energy from light while chemotrophs obtain energy from the chemical breakdown of compounds.

What are the potential effects of invasive species on local ecosystems?

They can outcompete native species, disrupt food webs, and alter habitat.

What does the concept of ecological succession illustrate?

The gradual process by which ecosystems change and develop over time.

What is the concept of carrying capacity in ecology?

The maximum population size of a species that the environment can sustain indefinitely.

What role do keystone species play within an ecosystem?

They have a disproportionately large effect on their environment relative to their abundance.

What method is commonly used to reconstruct evolutionary trees?

Molecular phylogenetics, which analyzes genetic sequences.

What is the function of the Golgi apparatus in eukaryotic cells?

It modifies, sorts, and packages proteins and lipids for secretion or use within the cell.

Why is it said that all life is connected?

Through evolutionary relationships and shared ancestry.

What are the signs of a healthy ecosystem?

High biodiversity, resilience to stress, and the ability to recover from disturbances.

What mechanism does lactobacillus use during yogurt production?

Fermentation to convert lactose into lactic acid.

What do scientists study to better understand evolutionary relationships in plants?

Molecular markers and morphological traits.

What is the role of decomposers in ecosystems?

They break down dead organic matter, recycling nutrients back into the ecosystem.

What is the impact of climate change on biodiversity?

It can lead to habitat loss, altered species distributions, and increased extinction rates.

What does abiotic factor refer to in ecology?

Non-living chemical and physical parts of the environment that affect living organisms.

What criterion is used to classify organisms within the same clade?

Shared derived characteristics that originate from a common ancestor.

What does it mean if a species is considered endangered?

It is at risk of extinction due to loss of habitat, changes in ecosystem dynamics, or other factors.

What is the consequence of overfishing on marine biodiversity?

It can lead to the depletion of fish populations and disrupt aquatic ecosystems.

What are the primary roles of nitrogen in living organisms?

Nitrogen is essential for amino acids, proteins, and nucleic acids.

What type of symbiotic relationship do bees and flowering plants represent?

Mutualism, where both parties benefit from the interaction.

What does the concept of evolution by natural selection imply?

That certain traits increase in frequency in a population due to their advantages in survival and reproduction.

How does energy flow through an ecosystem?

Energy is transferred from primary producers to consumers and then to higher trophic levels.

What can trigger an ecological cascade?

The removal or addition of key species or resources in an ecosystem.

What defines an ecosystem?

A community of living organisms and their interactions with the non-living environment.

What is the importance of biodiversity in relationship to ecosystem resilience?

High biodiversity enhances an ecosystem's ability to withstand and recover from disturbances.

What is the primary method for classifying prokaryotic organisms?

By their shape, cell wall characteristics, and metabolic pathways.

What is the ecological significance of coral reefs?

They provide habitat for numerous marine organisms and protect coastlines.

What evolutionary advantage do organisms gain from sexual reproduction?

Increased genetic diversity, enhancing adaptability to changing environments.

What is the role of mitochondria in eukaryotic cells?

To produce ATP through aerobic respiration.

Why are vertebrates considered a monophyletic group?

They share a common ancestor, which is reflected in their evolutionary tree.

What are the implications of habitat fragmentation for species?

It can isolate populations, reducing genetic diversity and increasing extinction risk.

What defines a successful invader species?

Its ability to thrive in new environments and disrupt local ecosystems.

How does genetic drift affect small populations?

It can lead to significant changes in allele frequencies due to chance events.

What is the significance of the fossil record in evolutionary biology?

It provides evidence of past life forms and helps track evolutionary changes over time.

What is the difference between primary and secondary succession?

Primary succession occurs in lifeless areas, while secondary succession occurs in previously inhabited areas after a disturbance.

What is the basic structure of a virus?

A core of genetic material (DNA or RNA) surrounded by a protein coat.

What does 'extinction' refer to in an ecological context?

The permanent loss of all members of a species.

What does ecological niche mean?

The role and position a species has in its environment, including all interactions.

What does conservation biology study?

The protection and management of biodiversity.

What are the key factors in determining species distribution?

Climate, habitat availability, and ecological interactions.

What is the purpose of using model organisms in biological research?

To gain insights applicable to other species, including humans.