Phylogenetic Classification System Quiz

Questions and Answers

Explain what is meant by the term phylogenetic classification system.

A phylogenetic classification system attempts to arrange species into groups based on their evolutionary origins and relationships using a hierarchy.

Define the term phylogenetic classification.

Grouping organisms according to their evolutionary relationships/links.

State the hierarchy of the taxons.

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

Define the term species.

A group of similar organisms capable of interbreeding to produce fertile offspring. Signup and view all the answers

Describe the tentative nature of classification.

Classification is not fixed/permanent and may change as more information/knowledge/techniques become available. Signup and view all the answers

State why the classification system is described as being discrete.

Classification is non-overlapping; at any level of classification, an organism belongs to one taxon and no other. Signup and view all the answers

State why the classification system is described as being hierarchical.

Smaller groups are arranged within larger groups and there is no overlap between groups. Signup and view all the answers

Define the term genus.

A group of closely related species/similar species capable of producing infertile hybrids. Signup and view all the answers

What was the classification of organisms originally based on?

Morphological (physical) features. Signup and view all the answers

Describe how the three domain classification system was developed.

Recent biochemical evidence showed that the kingdom prokaryote should be split into two groups based on biochemical differences. Signup and view all the answers

Define the term extremophile.

Organisms that can exist in a wide variety of environmental conditions, including extremes of temperature, pH, salinity, alkalinity, and pressure. Signup and view all the answers

What are the three domains?

Bacteria, Archaea, and Eukarya. Signup and view all the answers

What does the domain Eukarya include?

Plantae, Animalia, Fungi, and Protoctista. Signup and view all the answers

Outline the features of the kingdom Prokaryote.

Unicellular, prokaryotic cells, no tissue differentiation, autotrophic or heterotrophic. Signup and view all the answers

Outline the features of the kingdom Animalia.

Multicellular, eukaryotic cells, tissue differentiation, heterotrophic. Signup and view all the answers

Outline the features of the kingdom Plantae.

Multicellular, eukaryotic cells, tissue differentiation, autotrophic. Signup and view all the answers

Outline the features of the kingdom Fungi.

Single-celled or hyphal, eukaryotic cells, heterotrophic (saprotrophic or parasitic). Signup and view all the answers

Outline the features of the kingdom Protoctista.

Mainly unicellular, eukaryotic cells, no tissue differentiation. Signup and view all the answers

State the limitations of using physical features to assess the relatedness of organisms.

Distantly related organisms can display very similar physical features due to convergent evolution. Signup and view all the answers

State the term applied to features of organisms that have a common structure but different function.

Homologous. Signup and view all the answers

State the term applied to features of organisms that have common functions but different structures.

Analogous. Signup and view all the answers

Both dragonflies and birds have wings that enable them to fly. What conclusions can be drawn about the evolution of these structures?

They have evolved due to convergent evolution. The wings are analogous structures. Signup and view all the answers

Define the term analogous feature.

Similar features adapted to carry out the same function but have different evolutionary/developmental origin. Signup and view all the answers

Define the term homologous feature.

Similar features that have evolved from the same original structure for different functions. Signup and view all the answers

Define the term convergent evolution.

The independent evolution of similar features adapted to carry out the same function in species with distinct lineages. Signup and view all the answers

Define the term divergent evolution.

The evolution of similar structures from the same original structure in a common ancestor to perform different functions. Signup and view all the answers

Give an example of a homologous feature.

The limbs of reptiles, birds, and mammals (pentadactyl limb). Signup and view all the answers

Give an example of an analogous feature.

Wings of birds and insects. Signup and view all the answers

Describe how genetic fingerprinting can be used to assess the relatedness of organisms.

DNA fragments are displayed as bands on an electrophoresis gel. The pattern of the bands can be compared to show similarity between two DNA samples. Signup and view all the answers

Scientists can use protein structure to investigate the evolutionary relationships between different species. Explain why.

Compare the amino acid sequence in a specific protein. Greater similarity shows more closely related organisms. Signup and view all the answers

Comparing the base sequence of genes provides more evolutionary information than comparing the structure of proteins. Explain why.

Triplet code, more bases than amino acids, longer base sequence than amino acid sequence. Signup and view all the answers

Define the term species biodiversity.

The number of different species and the number of individuals of each species in a specified geographic region. Signup and view all the answers

State the advantages of using the binomial naming system.

Universal; avoids confusion caused by language barriers or common names. Signup and view all the answers

Describe how the binomial naming system is used.

Each organism is given two names: the genus (first word, capital letter) and species (second word, lower case). Signup and view all the answers

Define the term habitat.

The place in an ecosystem where an organism lives. Signup and view all the answers

Define the term population.

All the members of one species in an area that can breed with each other to produce fertile offspring. Signup and view all the answers

Define the term community.

All the members of all species in an area. Signup and view all the answers

Define the term succession.

A change in community and species composition over time. Signup and view all the answers

What does the Simpson's index measure?

The probability that two individuals randomly selected from a sample will belong to the same species. Signup and view all the answers

State the maximum theoretical value of Simpson's index.

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Outline the reasons why biodiversity is important.

It provides food, industrial materials, and new medicines. Signup and view all the answers

Explain the importance of sampling in measuring the biodiversity of a habitat.

Impossible/difficult to count every individual; samples provide estimates. Signup and view all the answers

Define the term taxon.

A group of organisms that share basic characteristics. Signup and view all the answers

Explain the difference between species richness and species evenness and why both measurements are needed to assess biodiversity.

Species richness is the number of species; species evenness is the abundance of each species. Signup and view all the answers

Outline the advantage of using biochemical methods to classify organisms.

Biochemical methods reduce mistakes made in classification due to convergent evolution. Signup and view all the answers

What do you need to determine in order to assess the biodiversity of a habitat?

The number of different species present and the number of individuals of each species. Signup and view all the answers

In terms of sampling, what is meant by the term 'uniform area'?

An area where the abiotic (non-living) variables are uniform. Signup and view all the answers

Briefly describe how you can sample a uniform area for non-motile organisms.

Mark out a grid, use random numbers for coordinates, place quadrat, and sample at each intersection. Signup and view all the answers

Explain why it is important that quadrats are placed randomly when sampling a uniform area for non-motile organisms.

To avoid/remove bias (experimenter choice). Signup and view all the answers

State what is meant by the term extinction.

All individuals of a species are dead/a species which has no living members. Signup and view all the answers

State the equation for calculating Simpson's diversity index, D.

1 - sum of n(n-1) / N(N-1). Signup and view all the answers

Define the term polymorphic gene/loci.

The existence of multiple alleles for the same gene/locus. Signup and view all the answers

Define the term polymorphism.

The presence of different forms/varieties co-existing in the same population. Signup and view all the answers

Define the term locus.

The position of a gene on a chromosome. Signup and view all the answers

Define the term allele.

Different forms of the same gene, occupying the same locus on homologous chromosomes. Signup and view all the answers

Define the term phenotype.

The appearance of an organism determined by the genotype. Signup and view all the answers

Define the term genotype.

The combination of alleles found in an individual. Signup and view all the answers

Proportion of polymorphic gene loci =

Number of polymorphic gene loci / total number of gene loci. Signup and view all the answers

The greater the proportion of polymorphic loci, the...

Greater the genetic diversity/genetic biodiversity. Signup and view all the answers

Classification of living organisms into bacteria, archaea, and eukaryota has been largely based on analysis of the gene coding for a ribosomal. Describe and explain how analysis of this gene can provide evidence for this modern theory of classification.

Compare base sequences of DNA in the gene. Organisms within a domain have a greater similarity to each other than with other domains. Signup and view all the answers

State the name for the mode/modes of nutrition used by the kingdom protoctista.

Some heterotrophic, some autotrophic. Signup and view all the answers

State the name for the mode/modes of nutrition used by the kingdom Animalia.

Heterotrophic. Signup and view all the answers

State the name for the mode/modes of nutrition used by the kingdom Fungi.

Heterotrophic. Signup and view all the answers

State the name for the mode/modes of nutrition used by the kingdom Plantae.

Autotrophic. Signup and view all the answers

State the name for the mode/modes of nutrition used by the kingdom Prokaryote.

Some autotrophic, some heterotrophic. Signup and view all the answers

Study Notes

Phylogenetic Classification System

Arranges species based on evolutionary origins and relationships.
Utilizes a hierarchy of taxa, with smaller groups nested within larger ones, ensuring no overlap.
Each group is termed a taxon (plural taxa).

Evolutionary Relationships

Phylogenetic classification groups organisms according to their evolutionary links.
Hierarchy of taxa includes: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

Species Definition

A species is defined as a group of similar organisms capable of interbreeding to produce fertile offspring.

Nature of Classification

Classification is not fixed; it evolves with advancements in knowledge and techniques.
Described as discrete since organisms belong to one taxon only.
Hierarchical due to the arrangement of smaller groups within larger ones.

Genus Definition

A genus consists of closely related species capable of producing infertile hybrids.

Historical Classification Basis

Originally based on morphological (physical) features and observable characteristics.

Three Domain Classification

Developed from biochemical evidence showing the kingdom Prokaryote should be divided into Bacteria and Archaea (extremophiles).
Eukarya includes all eukaryotic organisms, sharing unique ribosomal RNA sequences that indicate evolutionary relationships.

Extremophiles

Organisms thriving in extreme environmental conditions, such as temperature, pH, salinity, and pressure.

Kingdom Features

Prokaryote: Unicellular, no tissue differentiation, autotrophic or heterotrophic, reproduces by binary fission, cell wall present without cellulose or chitin.
Animalia: Multicellular, eukaryotic, tissue differentiation, heterotrophic, asexual or sexual reproduction, no cell wall, stores carbohydrates as glycogen.
Plantae: Multicellular, eukaryotic, autotrophic, photosynthetic, cell wall made of cellulose, stores carbohydrates as starch.
Fungi: Single-celled or filamentous (hyphal), eukaryotic, heterotrophic (saprotrophic or parasitic), spores with no flagella, cell wall made of chitin, stores carbohydrates as glycogen.
Protoctista: Mainly unicellular, eukaryotic, some autotrophic and some heterotrophic, variable forms showing plant-like and animal-like characteristics.

Evolutionary Features

Convergent evolution leads to similar physical traits in distantly related organisms, complicating classifications based on morphology.
Homologous features: Similar structures with different functions derived from a common ancestor.
Analogous features: Different structures serving similar functions, evolved independently.

Genetic and Protein Analysis

Genetic fingerprinting compares DNA patterns, where greater similarity infers closer relatedness.
Amino acid sequence comparisons reveal evolutionary relationships; fewer differences indicate closer ancestry.
Base sequence comparison of genes provides more evolutionary detail than protein structure comparisons due to longer sequences and presence of introns.

Biodiversity Metrics

Species biodiversity: Defined by the number of different species and individuals in a geographic region.
Species richness: Indicator of the number of species in a habitat.
Species evenness: Reflects the abundance of individuals for each species; both are crucial for assessing biodiversity.

Classification and Naming

Advantages of the binomial naming system include global universality and clarity, avoiding confusion from common names.
Organisms are named using genus and species, adhering to specific formatting rules (Latin, italics).

Biodiversity Importance and Measurement

Biodiversity supports food sources, industrial materials, and potential medicines.
Sampling biodiversity is vital for estimating population structures without exhaustive counting.

Extinction Definition

Extinction occurs when all individual members of a species are deceased.

Simpsons Diversity Index

Measures the likelihood that two randomly selected individuals belong to the same species.
Maximum theoretical value is 1.

Polymorphism and Genetic Diversity

Polymorphism: Presence of multiple alleles for a gene; contributes to genetic diversity.
The proportion of polymorphic loci directly correlates to genetic biodiversity.

This concise outline covers essential terms, definitions, and concepts related to classification and biodiversity, providing a solid foundation for study.

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Description

Test your knowledge on the phylogenetic classification system and the hierarchical organization of life forms. This quiz will explore key concepts such as taxon, species definition, and the evolutionary relationships between different organisms. Challenge yourself to understand how classification evolves over time!