Biology Species Classification Quiz

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Questions and Answers

Scientists have described and named a total of ______ species.

1.5 million

It is estimated that the total number of species is about ______.

10 million

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?

The branch of biology that classifies organisms and assigns each organism a universally accepted name. Signup and view all the answers

Organisms were first classified more than _ years ago by the Greek philosopher, __.

200, Aristotle Signup and view all the answers

What two groups did Aristotle first sort organisms into?

Plants and animals Signup and view all the answers

How did Aristotle divide animals?

Land dwellers, air dwellers, water dwellers Signup and view all the answers

What problems arose with original classification groups?

Many organisms were incorrectly classified, common names caused confusion, and many new organisms needed classification. Signup and view all the answers

In response to the need for a better system of classification, the Swedish naturalist, _______________, developed the system of classification that we still use today.

Carolus Linnaeus Signup and view all the answers

What was Linnaeus's classification system based on?

Structural similarity Signup and view all the answers

Linnaeus developed a system that placed an organism in a particular _ and assigned it a _________.

group, scientific name Signup and view all the answers

He developed a naming system called _______________ that is still in use today.

binomial nomenclature Signup and view all the answers

What does binomial nomenclature consist of?

Two parts Signup and view all the answers

He first divided all organisms into large groups that he called ___________.

kingdoms Signup and view all the answers

What are the two kingdoms Linnaeus's classification was based on?

Plant and animal Signup and view all the answers

Each subdivision of a kingdom is called a _ in the animal kingdom, or a _ in the plant kingdom.

phylum, division Signup and view all the answers

Each subset was further subdivided until he had developed ________ levels of classification.

7 Signup and view all the answers

What defines a species in Linnaeus's system?

Organisms can mate and produce fertile offspring. Signup and view all the answers

According to Linnaeus, what is the biggest, broadest group?

Kingdom Signup and view all the answers

The scientific name always consists of two words and _.

the genus and the species Signup and view all the answers

All scientific names are in _____ and understood by all scientists.

Latin Signup and view all the answers

Which name is always capitalized and which is never capitalized in scientific naming?

Genus, species Signup and view all the answers

Traditionally, what aspect of organisms was the basis for their classification?

Morphology Signup and view all the answers

What is morphology?

Classification based on the structures possessed by the organism. Signup and view all the answers

What are homologous structures?

Structures that have the same structure but different functions. Signup and view all the answers

What are analogous structures?

Similar in function but not in structure. Signup and view all the answers

What are vestigial structures?

Structures that are reduced in size and seem to be 'left over' from a previous ancestor. Signup and view all the answers

What does the fossil record give us clues about?

The morphology of ancient species. Signup and view all the answers

Similarity in ______________ provides evidence that organisms may be related.

cell structures Signup and view all the answers

Fossils show that organisms today are similar to organisms that are now .

alive, extinct Signup and view all the answers

What can similarities of ____________________ found within cells show relationships between organisms?

chemical compounds Signup and view all the answers

What serves as a 'molecular clock' in comparing proteins?

A comparison between the proteins of two organisms. Signup and view all the answers

What causes slight differences in DNA and proteins?

Mutations Signup and view all the answers

What is an indication that yeast and humans share?

A common ancestry Signup and view all the answers

What should be compared to see if two organisms have the same number and type of chromosomes?

Genetic similarities Signup and view all the answers

Similarities in ______________________________ provide evidence of phylogenetic relationships.

embryological development Signup and view all the answers

Some organisms show no similarities as adults, but are very, very similar as __________.

embryos Signup and view all the answers

What is cladistics?

A relatively new method of classifying organisms. Signup and view all the answers

What features does cladistics use to establish evolutionary relationships?

Shared derived characters Signup and view all the answers

What is a derived character?

A feature that evolved only within the group under consideration. Signup and view all the answers

Give an example of a derived character for birds.

Feathers Signup and view all the answers

What diagram shows the evolutionary relationships among a group of organisms?

Cladogram Signup and view all the answers

What is convergent evolution?

When two unrelated animals that occupy the same ecological role evolve similar traits. Signup and view all the answers

What was Linnaeus’s initial classification system based on?

2-kingdom system Signup and view all the answers

What do recent discoveries suggest about the classification of living things?

They fall naturally into 3 broad groups. Signup and view all the answers

What factors can act as barriers between species?

Physical characteristics, geographical barriers, behavioral barriers. Signup and view all the answers

What is an example of a scenario where offspring may survive but are not fertile?

Horse + donkey = mule Signup and view all the answers

Why do some organisms not come into contact with one another?

Geographical barriers. Signup and view all the answers

In what situation might mating occur, but the offspring do not survive?

Bullfrog eggs may be fertilized by the sperm of the leopard frog but do not survive. Signup and view all the answers

What often prevents mating in many organisms?

Behavioral barriers. Signup and view all the answers

What does convergent evolution refer to?

When two unrelated animals evolve similar traits due to occupying the same ecological role. Signup and view all the answers

If two species acquire similar characteristics from separate evolutionary processes, are those characters homologous or analogous?

They are analogous. Signup and view all the answers

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.