Tree of Life: Domains and Evolution

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Questions and Answers

What is the primary structure that forms sexual spores in Basidiomycetes?

Basidia (correct)

Hyphae

Sporangia

Zygospores

Which of the following best describes zygote formation in Zygomycota?

Is independent and does not involve hyphal structures

Involves the formation of basidiospores from basidia

Occurs through asexual spores called conidiospores

Results from the fusion of gametangia producing zygospores (correct)

What distinguishes a fairy ring in fungal growth?

It occurs exclusively in Zygomycetes

It indicates the age of the underground mycelium (correct)

It is formed from asexual spore production

It only occurs in dry, arid regions

Which of the following statements is true regarding protists?

They lack a common evolutionary heritage and are a diverse group Signup and view all the answers

Which organism's life cycle is characterized by causing intestinal infections in humans?

Giardia intestinalis Signup and view all the answers

What reproductive process occurs in Giardia intestinalis to produce genetically distinct progeny?

Sexual reproduction Signup and view all the answers

Which structure in Giardia intestinalis is responsible for survival outside the host's body?

Cyst Signup and view all the answers

Which of the following characteristics correctly describe protists?

Some are free-living; others are symbiotic or parasitic Signup and view all the answers

What is a distinct feature of the life cycle of cellular slime molds (e.g., Dictyostelia discoideum)?

They develop stalked sporangia when stressed Signup and view all the answers

In the context of Amoebozoa, how do these organisms typically move and feed?

With pseudopodia Signup and view all the answers

What characteristic is common among all members of the SAR super group?

Cellulose-containing cell walls Signup and view all the answers

Which form of Giardia intestinalis causes disease in humans?

Trophozoite form Signup and view all the answers

What is the primary function of the oral feeding groove in Excavata protists?

Capturing prey Signup and view all the answers

Which characteristic is NOT associated with bacterial endospores?

High water content Signup and view all the answers

Which of the following bacteria is classified as an obligate anaerobe?

Clostridium tetani Signup and view all the answers

What is the estimated impact of the Plague on Europe's population during the 14th century?

Killed approximately 75-200 million people. Signup and view all the answers

What process is primarily responsible for bacterial cell division?

Binary fission Signup and view all the answers

Which bacterial genus is known to form spores?

Clostridium Signup and view all the answers

Which type of photosynthesis does green sulfur bacteria perform?

Anoxygenic photosynthesis Signup and view all the answers

What is a key feature of the stationary phase in bacterial growth?

Cell growth ceases Signup and view all the answers

What is the primary way humans serve as hosts in the case of the Yersinia pestis bacterium?

They are incidental hosts. Signup and view all the answers

What distinguishes Archaea from Bacteria?

Archaea have a circular chromosome. Signup and view all the answers

Which statement about penicillin is accurate?

Penicillin was discovered by Sir Alexander Fleming in 1928. Signup and view all the answers

What role does lysozyme play in the human body?

It serves as an antibacterial enzyme present in tears. Signup and view all the answers

What is the significance of the discovery of lysozyme by Sir Alexander Fleming?

It revealed a natural antibacterial agent in human tears. Signup and view all the answers

What describes the oldest forms of life on Earth?

They are prokaryotes that can inhabit diverse habitats. Signup and view all the answers

What is a defining characteristic of prokaryotic cells?

Lack of cell organelles Signup and view all the answers

Which component is found in the cell wall of bacteria?

Peptidoglycan Signup and view all the answers

What is the function of plasmids in bacteria?

Transfer antibiotic resistance genes Signup and view all the answers

Which type of microscopy allows for visualization of bacteria at high magnification?

Light microscopy Signup and view all the answers

What is a unique feature of Gram-positive bacterial cell walls?

Up to 40 layers of peptidoglycan Signup and view all the answers

Which is true regarding the bacterial chromosome?

It is circular and located in the nucleoid Signup and view all the answers

Which of the following correctly describes the peptidoglycan structure in bacteria?

Features a sugar backbone linked by peptide chains Signup and view all the answers

Which type of bacterial cell wall contains an outer membrane?

Gram-negative Signup and view all the answers

Which statement about viruses is true concerning their ability to reproduce?

Viruses reproduce by hijacking the host's cellular machinery. Signup and view all the answers

How do viruses typically exit a host cell?

Via budding or lysis. Signup and view all the answers

Which characteristic indicates that viruses do not meet the definition of living things?

Viruses do not maintain homeostasis. Signup and view all the answers

What is one reason that suggests viruses might be considered lifelike?

Viruses can adapt and evolve through mutation. Signup and view all the answers

Which of the following best describes the composition of viral genomes?

Viral genomes can be made from either RNA or DNA. Signup and view all the answers

Which method of virus transmission is NOT recognized?

Viral transmission through food consumption. Signup and view all the answers

What verdict describes the ability of viruses to use energy?

Viruses rely on host cells for energy when replicating. Signup and view all the answers

What is the primary function of the capsid in a virus?

To protect the viral genome from environmental conditions. Signup and view all the answers

What type of structure do enveloped viruses possess?

Lipid membrane Signup and view all the answers

Which viral structure is characterized by a spherical shape formed from multiple copies of a single protein?

Icosahedral Signup and view all the answers

What is the primary way RNA viruses can differ in their genomes?

Whether they are double or single stranded Signup and view all the answers

Which component is essential for the retrovirus lifecycle where RNA is reverse transcribed into DNA?

Reverse transcriptase Signup and view all the answers

What characteristic distinguishes complex virion structures?

Combination of helical and icosahedral components Signup and view all the answers

Which type of genome cannot be translated into protein immediately?

Negative-sense RNA Signup and view all the answers

Which type of microorganisms are known to differ significantly in the gut microbiomes of obese and lean mice?

Bacteria Signup and view all the answers

What type of viral genome is typical for an enveloped virus like Varicella zoster virus?

Linear ds DNA Signup and view all the answers

In what form do viruses gain their envelopes during replication?

Via budding from the plasma membrane Signup and view all the answers

What role do fungi primarily play in ecosystems?

Recyclers of nutrients Signup and view all the answers

What type of relationship exists between mycorrhizae and plant roots?

Mutualism Signup and view all the answers

Which organism is specifically noted for its unicellular structure among fungi?

Saccharomyces cerevisiae Signup and view all the answers

What ecological benefit do lichens provide to barren areas?

Create soil from decay Signup and view all the answers

What is a characteristic feature of viruses?

They are obligate parasites that replicate within host cells. Signup and view all the answers

Which of the following contributions to global biomass is mainly attributed to microbes?

Nitrogen Signup and view all the answers

What process allows certain bacteria to convert atmospheric nitrogen into ammonia?

Nitrogen fixation Signup and view all the answers

In plant-bacterial mutualism, which statement about root nodules and rhizobia bacteria is correct?

The bacteria supply nitrogen to the plant. Signup and view all the answers

What is the estimated ratio of human cells to bacterial, fungal, and protist cells in the human microbiome?

1:10 Signup and view all the answers

How do microorganisms affect the Tree of Life?

They contribute significantly to global biomass. Signup and view all the answers

Which statement correctly describes the relationship of viruses with living organisms?

Viruses can infect a variety of living organisms. Signup and view all the answers

What distinguishes viruses from living cells?

Viruses lack cellular structures and means of independent replication. Signup and view all the answers

Study Notes

Overview of Lecture

The lecture will cover the Tree of Life, focusing on the three domains: Bacteria, Archaea, and Eukaryota.
Multicellular life evolved from single-celled organisms.
Linnaean classification and phylogenetic analysis are used to categorize organisms.
Life is diverse, and microorganisms dominate the Tree of Life.
Life evolved from a common ancestor.
All cellular life operates via DNA transcription into RNA and translation into proteins via ribosomes.
Evolution drives diversity by changing the blueprints over time.
Key processes of change result in new species.

The Tree of Life

The Tree of Life shows evolutionary relationships among organisms.
The fundamental unit of evolutionary classification is a taxon and can be grouped at differing levels.
Domains of life were developed by comparison of the genetic information of related organisms (16S rRNA).
Three domains of life exist: Bacteria, Archaea, and Eukarya.

Macroorganisms

Bacteria are a major form of microbial life.
Protists include Paramecium and other single-celled organisms.
Archaea are a category of microorganisms.
Fungi include Aspergillus and other multicellular organisms
Microorganisms dominate the Tree of Life, meaning these organisms are the most numerous life form

Microorganisms

Microbial Life evolved from a common ancestor
Principles for how life is structured:
DNA
RNA
Protein

Evolution

Organisms continually change over time.
This change ultimately leads to the creation of new related species.
The last universal common ancestor (LUCA) is the theoretical ancestor of all life on Earth.

Classification

Linnaean taxonomy is a method for classifying organisms based on shared characteristics.
It includes species, genus, family, order, class, phylum and kingdoms.

Phylogenetics

A method that studies evolutionary relationships from the perspective of genetic information and biochemical properties.
This is done by analyzing similarities in gene sequences and protein structures.

Horizontal Gene Transfer

The process by which genes can be passed between unrelated organisms.

Microbial Life in Extreme Environments

Extremophiles can survive in extreme conditions (i.e. high temps, pressure, saltwater).
These conditions test the limits of life as we know it and often include microorganisms such as bacteria and archaea.

Bacteria and Archaea

Archaea and bacteria are prokaryotes, meaning they do not have a nucleus and other membrane-bound organelles.
Bacteria and archaea are commonly seen as extremophiles, flourishing in extreme conditions of temperature and salinity.

Cell Structure

Bacterial and Archaeal cells have a cell wall made of peptidoglycan (bacteria) or other chemicals (archaea)
These cells have a plasma membrane that surrounds the cell, separating it from the external environment.

Bacterial Reproduction

Bacteria reproduce asexually by binary fission, creating two identical daughter cells.
This rapid rate of reproduction is a reason for their dominance in ecological environments.

Bacterial Metabolism

Bacteria exhibit metabolic diversity, including aerobic, anaerobic, and photosynthetic organisms.

Importance of Microorganisms

Microorganisms are essential to maintaining the balance of ecosystems.
They are involved in nutrient cycles, decomposition, and other vital processes.
They have a unique diversity, adaptability and abundance.

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Description

This quiz explores the Tree of Life, focusing on the three domains: Bacteria, Archaea, and Eukaryota. It delves into the evolution of multicellular life from single-celled organisms, the significance of Linnaean classification, and phylogenetic analysis. Test your understanding of how life diversifies through evolutionary processes.