Biological and Morphological Species Concepts

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Questions and Answers

What are the eight characteristics of living things?

Made of cells; 2. Reproduce; 3. Need and use energy; 4. Grow and develop; 5. Respond to stimuli; 6. Movement; 7. Exchange gases; 8. Excrete waste.

Why is classification important in biology?

Classification helps identify species, inform farming practices, assist in medical treatments, control invasive species, support conservation biology, and enables global communication about species.

What does the Morphological Species Concept focus on?

It focuses on the morphology of organisms, such as body size, shape, and structural features.

What is the primary advantage of the Biological Species Concept?

Its primary advantage is that it allows easy identification of species based on their ability to interbreed and produce viable offspring. Signup and view all the answers

What is a limitation of the Biological Species Concept?

It cannot be applied to species that reproduce asexually or to extinct species, limiting its utility. Signup and view all the answers

How does the Phylogenetic Species Concept define a species?

It defines a species as a cluster of organisms distinct from other clusters, showing a pattern of evolutionary relationships. Signup and view all the answers

What is a disadvantage of the Phylogenetic Species Concept?

A disadvantage is that the evolutionary history is not fully known for all species, which can complicate classifications. Signup and view all the answers

What happens once an organism is deemed a separate species?

It must be assigned a name, which can vary by region worldwide. Signup and view all the answers

What is Binomial Nomenclature and what does it consist of?

Binomial Nomenclature is a two-part naming system for species, consisting of the genus name (capitalized) followed by the species name (lowercase), both italicized. Signup and view all the answers

Why is hierarchical classification important in taxonomy?

Hierarchical classification organizes species from the most general to the most specific categories, allowing for better understanding of evolutionary relationships. Signup and view all the answers

What are the eight taxonomic categories in the classification system?

The eight taxonomic categories are Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species. Signup and view all the answers

How did Aristotle classify living things, and what limitation did his system have?

Aristotle classified living things into two groups: plants and animals, but this system became limited as many organisms did not fit neatly into these categories. Signup and view all the answers

What is a taxon in the context of classification?

A taxon is the name given to each rank in the classification system, representing a group of related organisms. Signup and view all the answers

Explain the significance of the first and second words in a scientific name.

The first word of a scientific name indicates the genus, while the second word specifies the species, together uniquely identifying an organism. Signup and view all the answers

What does the acronym 'Doctor King Phillip Came Over For Good Spaghetti' represent?

The acronym represents the order of the eight taxonomic categories: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species. Signup and view all the answers

Discuss the role of species concepts in classification.

Species concepts help determine which groups of organisms constitute a species, aiding in the formal naming and classification of those organisms. Signup and view all the answers

What is the primary process by which prokaryotes produce energy, and how does it differ in the presence or absence of oxygen?

Prokaryotes produce energy primarily through aerobic or anaerobic respiration. Aerobic respiration requires oxygen, while anaerobic respiration does not. Signup and view all the answers

Define obligate aerobes and obligate anaerobes in terms of their oxygen requirements.

Obligate aerobes require oxygen to survive, while obligate anaerobes are killed by oxygen. Signup and view all the answers

What distinguishes facultative anaerobes from obligate anaerobes?

Facultative anaerobes can survive with or without oxygen, whereas obligate anaerobes cannot tolerate oxygen at all. Signup and view all the answers

Describe the process of binary fission in bacteria and its significance.

Binary fission involves the replication of a single chromosome, cell growth, and division into two identical cells. It is significant because it allows rapid asexual reproduction in bacteria. Signup and view all the answers

How do cyanobacteria differ from plants in terms of cellular structure and reproduction?

Cyanobacteria are prokaryotic and do not have membrane-bound organelles like chloroplasts, and they reproduce asexually through binary fission. In contrast, plants are eukaryotic with complex cellular structures. Signup and view all the answers

What was Ernst Haeckel's contribution to the classification of microorganisms?

He proposed classifying all microorganisms into a third category called Kingdom Protista. Signup and view all the answers

What distinguishes Archaebacteria from Bacteria?

Archaebacteria can live in extreme environments and have different RNA and protein structures than Bacteria. Signup and view all the answers

Describe the term 'prokaryote' and give a key characteristic.

A prokaryote is an organism without a nucleus, and a key characteristic is that it has no membrane-bound organelles. Signup and view all the answers

List two differences between prokaryotic and eukaryotic cells.

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells contain them. Signup and view all the answers

What are the three general shapes of bacteria?

Bacteria can be spherical (coccus), rod-shaped (bacillus), or spiral (spirillum). Signup and view all the answers

What is the function of the cell wall in bacteria?

The cell wall provides support and protection to the bacterial cell. Signup and view all the answers

How do prokaryotes differ in their ability to obtain energy?

Prokaryotes can obtain energy from various sources, being either heterotrophic or autotrophic. Signup and view all the answers

What is the role of ribosomes in bacteria?

Ribosomes in bacteria are responsible for the formation of proteins. Signup and view all the answers

How do bacteria reproduce sexually, and what role do pili play in this process?

Bacteria reproduce sexually through conjugation, forming a tube between two bacteria to exchange genetic material, with pili holding them together. Signup and view all the answers

Why are viruses not classified as living organisms?

Viruses are not classified as living organisms because they cannot live independently and must invade host cells to utilize their machinery for reproduction and survival. Signup and view all the answers

Describe the characteristics and classification criteria of viruses.

Viruses are classified based on their size, shape of the capsid, and the diseases they cause, with some common shapes including spherical and cylindrical. Signup and view all the answers

What are the differences in mutation rates between RNA and DNA viruses?

RNA viruses tend to have higher mutation rates compared to DNA viruses, which are usually more stable and have effective vaccines. Signup and view all the answers

Explain the lytic cycle of virus reproduction and its stages.

In the lytic cycle, a virus enters a host cell, replicates itself many times, and bursts out of the cell, destroying it. The stages include attachment, injection, replication, assembly, and release. Signup and view all the answers

What happens during the lysogenic cycle of a virus?

During the lysogenic cycle, the virus enters the cell and integrates its DNA with the host DNA, becoming inactive as a provirus while the host functions normally. Signup and view all the answers

How does the structure of a virus's capsid influence its classification?

The structure of a virus's capsid, which can have various shapes like small crystals or spheres, influences its classification by providing important distinguishing characteristics. Signup and view all the answers

What impact do environmental changes have on lysogenic viruses?

Environmental changes can cause lysogenic viruses to exit their dormant state and enter the lytic cycle, leading to active replication and cell destruction. Signup and view all the answers

What evidence supports the endosymbiotic theory regarding mitochondria and chloroplasts?

Mitochondria and chloroplasts have two membranes, ribosomes resembling prokaryotes, reproduce by binary fission, and contain circular DNA similar to prokaryotes. Signup and view all the answers

What are the main groups of protists, and give an example of each?

The three groups of protists are animal-like (e.g., amoebas), fungus-like (e.g., slime moulds), and plant-like (e.g., diatoms). Signup and view all the answers

How do animal-like protists obtain their nutrients?

Animal-like protists are heterotrophs that obtain nutrients by consuming other organisms, including plants, animals, and prokaryotes. Signup and view all the answers

Name the four phyla of animal-like protists and provide one characteristic for each.

Phylum Cercozoa (varying shapes), Phylum Ciliophora (covered in cilia), Phylum Zoomastigina (flagellated), Phylum Sporozoa (obligate parasites). Signup and view all the answers

What is a distinctive feature of the membranes of mitochondria and chloroplasts?

They have two membranes, with the inner membrane similar to that of prokaryotes and the outer membrane resembling the eukaryotic cell membrane. Signup and view all the answers

What kind of reproduction do mitochondria and chloroplasts utilize?

Mitochondria and chloroplasts reproduce by binary fission. Signup and view all the answers

Discuss the primary characteristic that distinguishes protozoans from other protists.

Protozoans are primarily distinguished by their heterotrophic lifestyle, consuming other organisms for nutrition. Signup and view all the answers

Describe one reason why protists are often classified as 'misfits' in the domain Eukarya.

Protists exhibit a wide variety of characteristics and do not fit neatly into the categories of plants, animals, or fungi. Signup and view all the answers

Study Notes

Taxonomy

Classifying living things involves 8 characteristics: made of cells, reproduce, need and use energy, grow and develop, respond to stimuli, move, exchange gases, and excrete waste.
Classifying is important for identifying species, farming practices, medical disease identification, treatment, invasive species control, conservation biology, and global communication about species.
Morphological Species Concept focuses on the physical characteristics (morphology) of organisms like body size and shape to determine species similarity.
Advantages of morphological species concept: simple.
Disadvantages: Populations can have non-identical individuals.
Biological Species Concept defines a species based on organisms capable of interbreeding naturally and producing viable offspring.
Organisms might appear similar but be different species.
Advantages: Easy to determine if similar organisms are the same species.
Disadvantages: Not applicable to all species. Doesn't apply to extinct species or asexually reproducing species.

Phylogenetic Species Concept

Focuses on evolutionary relationships among organisms.
A species is a distinct cluster of organisms from other clusters showcasing relationships among organisms.
Advantage: Can be applied to extinct species and uses modern DNA analysis.
Disadvantage: Evolutionary history is not always known for all species.

Naming Species

A standardized system (binomial nomenclature) is essential for naming species universally.
This system uses a two-part Latin name.
First part: Genus (capitalized). Second part: Species (lowercase).
Both parts are written in italics when typed and underlined when handwritten.

Classifying Species

Species concepts help determine what species are.
Binomial nomenclature creates official species names.
Classification groups organisms based on criteria, revealing evolutionary relationships.
Hierarchical classification - from most general categories to most specific.

Taxonomic Categories

Organisms are grouped in nested categories (e.g., species, genus, family).
Specific, numbered ranks (levels) and specific taxa (names) are included in taxonomy.

Bacteria

Cell Wall Structure
Gram positive: two layers (lipid, peptidoglycan). Gram negative: three layers (lipid, peptidoglycan, lipopolysaccharide).
Obtaining Nutrients: Autotrophs (make their own organic compounds from CO2) and heterotrophs (obtain energy by breaking down organic molecules from their environment).
Respiration (energy creation): Aerobic respiration (requires oxygen), anaerobic respiration (does not require oxygen), and facultative anaerobes (can survive with or without oxygen).

Characteristics of Bacteria

Mostly single-celled.
No nucleus or membrane-bound organelles.
Cell walls.
Circular chromosomes.
Reproduce asexually or sexually.
Prokaryotic.
Anaerobic or aerobic.
Heterotrophic or Autotrophic.
Structure: Very small.

Bacteria Contain

Cell Wall (support and protect cell).
Cell membrane (controls what enters/exits cell).
Ribosomes (formation of proteins).
DNA (single strand in a ring shape).
Some contain flagella (movement).

Bacteria cell shapes

Spherical (Coccus).
Rod-shaped (Bacillus).
Spiral (Spirillum).

Bacteria Diseases

Coccus (e.g., Streptococci, Staphylococcus).
Bacilli (e.g., E. Coli).
Spirochetes (e.g., Borrelia burgdorferi).

Gram Stain

Classifies bacteria based on their reaction to a crystal violet/iodine dye.
Gram-positive bacteria retain the violet stain; Gram-negative bacteria appear pink.

Viruses

Obligate intracellular parasites (must reproduce inside a host cell).
Possess genetic material (DNA or RNA), but lack cellular structure.
Viral Structure: Genetic Material (DNA or RNA) - encased in a protein coat (capsid). Some have lipid envelope.
Classifying: Size and shape of capsid. Some also classified based on diseases they cause.
Reproduction: Lytic cycle (replication and destruction of host cell) Lysogenic (replication but does not destroy host cell - the viral DNA becomes part of the host - called the provirus/prophage)
Virus Differences: Lytic destroys the host cell, Lysogenic does not.

Retroviruses

These viruses use reverse transcriptase to convert RNA into DNA, which then incorporates into the host cell's DNA.
Retroviruses use reverse transcriptase to convert RNA into DNA which then incorporates into the host's DNA - making a viral provirus.

Herpes Viruses

Viral disease causing cold sores, which can appear and disappear throughout a lifetime.
Recurring infections, because the virus is in a latent form. It stays dormant in the host's body, within the nerve cells, until activated.

Prions

Infectious proteins that cause diseases by altering normal proteins into abnormal shapes.
Non-genetic diseases.
Lack DNA and RNA.
Usually affect the central nervous system of animals.

Protists

Eukaryotic organisms (possess a nucleus and other membrane-bound organelles)
Primarily unicellular, although some are multicellular.
Diverse groups, difficult to clearly classify into only one category

Animal-like protists (protozoans)

Heterotrophic (consuming other microorganisms or organic matter for energy and nutrients).
Classified into 4 main phyla: Cercozoa, Ciliophora, Zoomastigina, and Sporozoa.
Some species are parasites; others are free-living, not dependent on another organism.

Fungus-like protists

Obtain nutrition from dead organisms or non-living matter.
Divided into 3 main groups: plasmodial slime molds, cellular slime molds, and water molds.
Typically live in moist environments and produce spores.

Plant-like protists (algae)

Autotrophs (carry out photosynthesis)
Essential for primary production in aquatic ecosystems.
Divided into different groups based on their pigment composition and other characteristics.

Diatoms

Unicellular algae with silical walls.
Important component of phytoplankton.

Dinoflagellates

Unicellular algae with two flagella.
Some species produce toxins that cause "red tides."

Euglenoids

Unicellular and can be autotrophic (using photosynthesis) or heterotrophic (consuming other organisms).
Presence of a flagellum.

Paramecium

Are ciliates.
Covered with cilia(hair-like projections).
Important in aquatic ecosystems.

Water molds

Filamentous, can be parasitic to plants and animals..
Important decomposers of organic material in freshwater ecosystems.

Zoomastigina

Possess flagella for movement.
Many species live freely, and some are parasitic.

Sporozoans

Non-motile.
Characterized by their complex life cycles, often involving vectors.
Malaria is a disease caused by some sporozoans.

Viruses (cont.)

Viral Replication: Lytic cycle (destroys host cells or lysogenic cycle (does not destroy host cell - integrated into DNA, can be dormant).
Virus Classifications: DNA, or RNA.

Application of Viruses

Biological research
Treating bacterial diseases.
Biological insecticides.

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Description

This quiz explores the classification of living organisms with a focus on the Biological and Morphological Species Concepts. You will learn about the characteristics used to define species and the advantages and disadvantages of each concept. Understanding these concepts is crucial for various fields including conservation biology, medicine, and agriculture.