Podcast
Questions and Answers
Scientists have described and named a total of ______ species.
Scientists have described and named a total of ______ species.
1.5 million
It is estimated that the total number of species is about ______.
It is estimated that the total number of species is about ______.
10 million
What is Darwin's Theory of Evolution?
What is Darwin's Theory of Evolution?
Organisms produce more offspring than can survive, leading to competition for resources. Those best suited to their environment survive and reproduce, causing natural selection.
What is taxonomy?
What is taxonomy?
Organisms were first classified more than _____ years ago by the Greek philosopher, ______.
Organisms were first classified more than _____ years ago by the Greek philosopher, ______.
What two groups did Aristotle first sort organisms into?
What two groups did Aristotle first sort organisms into?
How did Aristotle divide animals?
How did Aristotle divide animals?
What problems arose with original classification groups?
What problems arose with original classification groups?
In response to the need for a better system of classification, the Swedish naturalist, _______________, developed the system of classification that we still use today.
In response to the need for a better system of classification, the Swedish naturalist, _______________, developed the system of classification that we still use today.
What was Linnaeus's classification system based on?
What was Linnaeus's classification system based on?
Linnaeus developed a system that placed an organism in a particular _______ and assigned it a _______________.
Linnaeus developed a system that placed an organism in a particular _______ and assigned it a _______________.
He developed a naming system called _______________ that is still in use today.
He developed a naming system called _______________ that is still in use today.
What does binomial nomenclature consist of?
What does binomial nomenclature consist of?
He first divided all organisms into large groups that he called ___________.
He first divided all organisms into large groups that he called ___________.
What are the two kingdoms Linnaeus's classification was based on?
What are the two kingdoms Linnaeus's classification was based on?
Each subdivision of a kingdom is called a _______ in the animal kingdom, or a _______ in the plant kingdom.
Each subdivision of a kingdom is called a _______ in the animal kingdom, or a _______ in the plant kingdom.
Each subset was further subdivided until he had developed ________ levels of classification.
Each subset was further subdivided until he had developed ________ levels of classification.
What defines a species in Linnaeus's system?
What defines a species in Linnaeus's system?
According to Linnaeus, what is the biggest, broadest group?
According to Linnaeus, what is the biggest, broadest group?
The scientific name always consists of two words ______ and _______.
The scientific name always consists of two words ______ and _______.
All scientific names are in _____ and understood by all scientists.
All scientific names are in _____ and understood by all scientists.
Which name is always capitalized and which is never capitalized in scientific naming?
Which name is always capitalized and which is never capitalized in scientific naming?
Traditionally, what aspect of organisms was the basis for their classification?
Traditionally, what aspect of organisms was the basis for their classification?
What is morphology?
What is morphology?
What are homologous structures?
What are homologous structures?
What are analogous structures?
What are analogous structures?
What are vestigial structures?
What are vestigial structures?
What does the fossil record give us clues about?
What does the fossil record give us clues about?
Similarity in ______________ provides evidence that organisms may be related.
Similarity in ______________ provides evidence that organisms may be related.
Fossils show that organisms ______ today are similar to organisms that are now ______.
Fossils show that organisms ______ today are similar to organisms that are now ______.
What can similarities of ____________________ found within cells show relationships between organisms?
What can similarities of ____________________ found within cells show relationships between organisms?
What serves as a 'molecular clock' in comparing proteins?
What serves as a 'molecular clock' in comparing proteins?
What causes slight differences in DNA and proteins?
What causes slight differences in DNA and proteins?
What is an indication that yeast and humans share?
What is an indication that yeast and humans share?
What should be compared to see if two organisms have the same number and type of chromosomes?
What should be compared to see if two organisms have the same number and type of chromosomes?
Similarities in ______________________________ provide evidence of phylogenetic relationships.
Similarities in ______________________________ provide evidence of phylogenetic relationships.
Some organisms show no similarities as adults, but are very, very similar as __________.
Some organisms show no similarities as adults, but are very, very similar as __________.
What is cladistics?
What is cladistics?
What features does cladistics use to establish evolutionary relationships?
What features does cladistics use to establish evolutionary relationships?
What is a derived character?
What is a derived character?
Give an example of a derived character for birds.
Give an example of a derived character for birds.
What diagram shows the evolutionary relationships among a group of organisms?
What diagram shows the evolutionary relationships among a group of organisms?
What is convergent evolution?
What is convergent evolution?
What was Linnaeus’s initial classification system based on?
What was Linnaeus’s initial classification system based on?
What do recent discoveries suggest about the classification of living things?
What do recent discoveries suggest about the classification of living things?
What factors can act as barriers between species?
What factors can act as barriers between species?
What is an example of a scenario where offspring may survive but are not fertile?
What is an example of a scenario where offspring may survive but are not fertile?
Why do some organisms not come into contact with one another?
Why do some organisms not come into contact with one another?
In what situation might mating occur, but the offspring do not survive?
In what situation might mating occur, but the offspring do not survive?
What often prevents mating in many organisms?
What often prevents mating in many organisms?
What does convergent evolution refer to?
What does convergent evolution refer to?
If two species acquire similar characteristics from separate evolutionary processes, are those characters homologous or analogous?
If two species acquire similar characteristics from separate evolutionary processes, are those characters homologous or analogous?
Study Notes
Species Classification
- Scientists have documented approximately 1.5 million species, although estimates suggest the total number could be around 10 million.
Darwin's Theory of Evolution
- Organisms tend to produce more offspring than can survive, resulting in competition for limited resources.
- Best-adapted individuals survive, reproduce, and pass on their advantageous traits through the process of natural selection.
- This process has influenced the apparent diversity of life, with modern species descending from ancestral forms.
Taxonomy and Classification
- Taxonomy is the biological branch that classifies organisms and provides them with universally accepted names.
- The classification system originated over 2000 years ago, credited to Aristotle, who categorized organisms into plants and animals.
Linnaean System of Classification
- Carolus Linnaeus established the classification system based on structural similarities among organisms.
- He created a binomial nomenclature system consisting of two parts: the genus and species names, both in Latin and italicized.
Levels of Classification
- Linnaeus structured organisms into kingdoms, phyla (animal kingdom), and divisions (plant kingdom), culminating in seven levels of classification.
- More recently, a domain level was added above kingdoms, recognizing three broad categories of life.
Classification Criteria
- Homologous structures indicate common ancestry and closely related species, while analogous structures show similar functions without common inheritance.
- Morphology, the structure of organisms, was foundational in Linnaeus' classification, although modern taxonomy also considers genetic and evolutionary factors.
Genetic and Evolutionary Evidence
- Similarities in cellular structures, chemical compounds, and embryological development provide additional evidence of relationships among organisms.
- Differences in proteins and genes serve as indicators of evolutionary divergence and shared ancestry.
Cladistics and Evolutionary Relationships
- Cladistics classifies organisms based on shared derived characteristics, illustrating evolutionary relationships through cladograms.
- Convergent evolution results in unrelated species appearing similar due to similar ecological roles.
Barriers to Species Interbreeding
- Physical characteristics can prevent mating between species, limiting possible offspring.
- Geographical barriers like distance keep species from encountering one another.
- Behavioral barriers may impede mating, especially in animals requiring specific courtship behaviors.
Summary of Evolutionary Concepts
- Understanding whether traits are homologous (common origin) or analogous (separate evolution) helps clarify relationships among species.
- The study of evolutionary relationships continues to evolve as new discoveries shape classification systems, emphasizing the interconnectedness of life on Earth.
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Description
Test your knowledge on species classification and Darwin's Theory of Evolution. This quiz covers key facts about the number of species known to science and the principles of evolution. Perfect for biology students looking to reinforce their understanding.
