AP Biology : Understanding Classifications

Study concepts, example questions & explanations for AP Biology

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Example Questions

Example Question #1 : Microorganisms And Viruses

Which of the following would not be considered an organism?

Possible Answers:

A plant

An archaebacterium

A prion

A bacterium

A fungus

Correct answer:

A prion

Explanation:

Prions are simply proteins, typically in a misfolded shape. They are simply molecules that can cause disease by inducing other proteins to misfold.

The qualifications for life include growth or reproduction, nutrient absorption, and composition of cells. Prions fit none of these criteria. Bacteria, archaea, fungi, and plants are all major classes of living organisms.

Example Question #2 : Microorganisms And Viruses

Which of the following is classified as eukaryotic?

Possible Answers:

Bacteria

Archaea

Prokaryotes

Protista

Correct answer:

Protista

Explanation:

All species can be defined as either prokaryotes or eukaryotes. Prokaryotes are always single-celled and have no membrane-bound organelles. All bacteria and archaea are prokaryotes. Eukaryotes can be unicellular or multicellular and have membrane-bound organelles, including a nucleus. Protista is a sub-category of eukaryotes that are unicellular.

Example Question #1191 : Ap Biology

What type of microorganism is composed only of a protein capsule encasing genetic material?

Possible Answers:

Virus

Bacteria

Protozoa

Helminth

Fungus

Correct answer:

Virus

Explanation:

A virus is the smallest of the microorganisms, consisting genetic material and a protein coat. The virus takes over the host's cellular functions to reproduce, and carries no organelles of its own.

Bacteria prokaryotic cells, while fungi are eukaryotic cells. Protozoa are a sub-classification within the protista kingdom and are unicellular eukaryotes. Helminth are parasitic worms composed of eukaryotic cells.

Example Question #1 : Understanding Classifications

Which of the following is not considered to be living?

Possible Answers:

Fungi

Cyanobacteria

Halophiles

Obligate anaerobes

Viruses

Correct answer:

Viruses

Explanation:

Viruses are not considered to be living organisms because they do not meet many of the criteria for "life", as defined by biologists. Viruses are incapable of energy metabolism, growth, response to stimuli, and independent reproduction. Viruses are simply a core of genetic material surrounded by a coat of protien, and require a living host to multiply. 

All other answer options are specific examples of living organisms. Obligate anaerobes are a classification of bacteria that require minimal levels or lack of oxygen to survive. Fungi are a kingdom of organisms in the domain Eukarya. Cyanobacteria are a phylum of bacteria that obtain energy through photosynthesis. Halophiles are organisms that best survive in high salt concentrations.

Example Question #1 : Microorganisms And Viruses

The probability a diagnostic test will return a positive test result when the organism or condition is present is known as the __________ of the diagnostic test.

Possible Answers:

sensitivity

predictive value

false positive rate

accuracy

specificity

Correct answer:

sensitivity

Explanation:

All diagnostic tests have the chance probability of not detecting the condition. Thus, the percentage of samples for which the test is accurate with a positive result is the sensitivity of the test.

Example Question #2 : Understanding Classifications

Bdelloid rotifers are microscopic freshwater organisms whose females develop from unfertilized eggs. Which of the following best describes this form of reproduction?

Possible Answers:

Gynogenesis

None of the choices

Parthenogenesis

Sexual reproduction

Binary fission

Correct answer:

Parthenogenesis

Explanation:

Parthenogenesis is a type of asexual reproduction that can be found in plants, fish, birds, reptiles, and several others. This type of reproduction does not require fertilization to form an embryo, rather the embryo develops from an unfertilized egg. 

An advantage of this system is that it does not require energy to search for a compatible mate, and allows the species to continue if organisms are isolated from one another. A disadvantage is the lack of genetic diversity, which does not help the species as much in the long term. 

Example Question #1191 : Ap Biology

General nomenclature classifies humans by the name homo sapiens. This means that homo belongs to which level of classification?

Possible Answers:

Genus

Order

Species

Family

Kingdom

Correct answer:

Genus

Explanation:

The order of classification from top to bottom is: kingdom, phylum, class, order, family, genus, species. Binomial nomenclature includes the two most specific classifications of an organism. Homo therefore falls into the genus level of classification.

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