Biology Chapter 4 Flashcards

Questions and Answers

What does the term 'Systematic, Taxonomy, and Nomenclature' refer to?

Science of naming groups of organisms (correct)

Inferring evolutionary relationships only

Classifying organisms only

Process of collecting organisms

What is Binomial Nomenclature?

A system of naming in which each species is assigned a two-part name consisting of its genus (first) and species (last).

Who devised the Linnaean System of Classification?

Carolus Linnaeus

What are the most inclusive and least inclusive categories in the Linnaean Hierarchy?

Domain and Species Signup and view all the answers

What are the three criteria for recognizing species?

<ol> <li>Common descent must trace heritage to an ancestor 2. Smallest distinct grouping of organisms sharing patterns of ancestry 3. Reproductive community pertains to sexually reproducing species.</li> </ol> Signup and view all the answers

What does the Biological Species Concept (BSC) state?

A species is a reproductive community of populations that occupies a specific niche in nature. Signup and view all the answers

Which of the following is a criticism of the Biological Species Concept?

Does not account for organisms that interbreed with recent common ancestors Signup and view all the answers

What is the Evolutionary Species Concept (ESC)?

A lineage of ancestor-dependent populations maintaining identity from other lineages with evolutionary tendencies and fate. Signup and view all the answers

What does the Cohesive Species Concept (CSC) imply?

It suggests compatibility through ancestral genome modifications via genetic drift, gene flow, and natural selection. Signup and view all the answers

What is the Phylogenetic Species Concept (PSC)?

An irreducible grouping of organisms that is diagnosably distinct from other groups. Signup and view all the answers

What is a species?

A group of interbreeding individuals of common ancestry that are reproductively isolated from all other such groups. Signup and view all the answers

How do we originally put organisms into groups?

By morphology, which we now call these similarities homologies. Signup and view all the answers

What is phylogeny?

Addition of a time scale and common ancestors turns a cladogram into an evolutionary tree or phylogeny. Signup and view all the answers

How can we explain morphological similarities between unrelated species?

Analogy or homoplasy refers to similarity of structure or function due to convergent evolution. Signup and view all the answers

What is a character in the context of classification?

Any feature used to infer relationships within and among groups of organisms. Signup and view all the answers

What is the difference between cladistic analysis and phylogenetic analysis?

Cladistic analysis focuses on constructing cladograms, while phylogenetic analysis focuses on constructing phylogenies. Signup and view all the answers

What does polarity signify in classification?

The ordering of character states as ancestral or derived and the range of variation. Signup and view all the answers

What is an out-group?

A group that is closely related to, but not a member of the in-group (the group being studied). Signup and view all the answers

What is a paraphyletic group?

A group that includes the most recent common ancestor of all its members. Signup and view all the answers

What is a polyphyletic group?

A group that does not include the most recent common ancestor of all its members. Signup and view all the answers

What defines a monophyletic group?

All members are descended from the same common ancestor. Signup and view all the answers

What is polyphyly?

A group comprising taxa with four-chambered hearts, defined by convergent characters. Signup and view all the answers

Study Notes

Classification Principles

Systematic, taxonomy, and nomenclature are essential in organizing and naming groups of organisms, revealing their evolutionary connections.

Binomial Nomenclature

Each species adopts a two-part naming system, consisting of the genus (first part) and species (second part), typically italicized or underlined.

Linnaean Classification System

Developed by Carolus Linnaeus, this system categorizes life into hierarchies: Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species.

Hierarchical Inclusion

The Domain is the most inclusive category, while Species is the least inclusive in the Linnaean hierarchy.

Criteria for Species Recognition

Common descent traces back to a shared ancestor.
Organisms form the smallest distinct group with shared ancestry.
A reproductive community is identified in sexually reproducing species.

Biological Species Concept (BSC)

Defines species as reproductive communities within specific ecological niches.

Criticisms of BSC

Questions arise regarding interbreeding capabilities among recent common ancestors.
Asexual organisms are often excluded, and reproductive isolation varies in strength.

Evolutionary Species Concept (ESC)

Describes species as ancestor-dependent lineages, distinct yet sharing evolutionary trends, applicable to both sexual and asexual reproduction.

Cohesive Species Concept (CSC)

Focuses on a shared ancestral genome modified by genetic drift, gene flow, and natural selection.

Phylogenetic Species Concept (PSC)

Defines species based on irreducible groupings, distinctiveness, and ancestry separation patterns.

Understanding Species

A species comprises interbreeding individuals with a common ancestor, isolated from other groups.

Grouping Organisms

Initially based on morphology and today on homologies, indicating hierarchical relationships among groups.

Phylogenetic Analysis

Incorporates a time scale and common ancestry to transform a cladogram into a phylogenetic tree.

Explaining Morphological Similarities

Analogies or homoplasies arise from convergent evolution, where unrelated species develop similar traits.

Character Definition

A character is any trait used to infer interrelationships, which can be morphological, behavioral, or biochemical.

Cladistic and Phylogenetic Analysis

Cladistic analysis involves creating cladograms, while phylogenetic analysis focuses on constructing evolutionary trees.

Polarity in Character States

Refers to the determination of whether character states are ancestral or derived, along with their variations.

Understanding Groups

Out-group: a closely related group not part of the in-group under study.
Paraphyletic group: includes the most recent common ancestor and some, but not all, descendants.
Polyphyletic group: does not encompass the most recent common ancestor.
Monophyletic group: all members originate from a single common ancestor.
Polyphyly refers to groups formed from taxa sharing convergent traits, such as four-chambered hearts.

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Description

Test your knowledge on the principles of classification in biology with these flashcards. Topics include systematic taxonomy, nomenclature, and binomial nomenclature. Perfect for students looking to strengthen their understanding of how organisms are classified.