A single-celled bacterium swims toward a higher concentration of sugar in its surroundings. Which property of life does this behavior show?
Response to stimuli
✓
Reproduction
Homeostasis
Evolution
Correct Answer
Response to stimuli
Moving toward or away from a chemical signal, called chemotaxis, is a response to a stimulus in the environment. Reproduction is making new individuals, which swimming does not do. Homeostasis is keeping internal conditions stable, not moving toward food. Evolution is change in a population over generations, not a single cell's behavior.
Category: Properties of Life
Question 2
Which term describes an organism's ability to keep its internal conditions, such as temperature and water balance, within a stable range?
Adaptation
Homeostasis
✓
Metabolism
Development
Correct Answer
Homeostasis
Homeostasis is the regulation of the internal environment within narrow limits even when outside conditions change. Adaptation is an inherited trait that suits an organism to its environment. Metabolism is the set of chemical reactions that process energy and matter. Development is the series of changes an organism goes through as it grows.
Category: Properties of Life
Question 3
In the hierarchy of biological organization, groups of similar cells that work together to carry out a related function form which level?
Organ
Organelle
Tissue
✓
Organ system
Correct Answer
Tissue
A tissue is a group of similar cells performing a related function, such as muscle or nerve tissue. An organ is a structure built from several kinds of tissue. An organelle is a structure inside a cell, a level below the cell. An organ system is a group of organs working together, a level above organs.
Category: Levels of Organization
Question 4
All the populations of different kinds of organisms living and interacting in one area make up which level of organization?
Population
Ecosystem
Biosphere
Community
✓
Correct Answer
Community
A community is the set of all populations of different species in a given area. A population includes members of only one species. An ecosystem adds the nonliving parts of the environment to the living community. The biosphere is the sum of all ecosystems on Earth.
Category: Levels of Organization
Question 5
All the living things in an area together with the nonliving parts of that local environment, such as water, soil and sunlight, make up a(n)
Ecosystem
✓
Population
Organ system
Organism
Correct Answer
Ecosystem
An ecosystem includes all the organisms in an area plus the abiotic, or nonliving, factors they interact with. A population is a group of one species and does not include nonliving factors. An organ system is a level of organization within a single body. An organism is one individual living thing.
Category: Levels of Organization
Question 6
Small, specialized structures enclosed by membranes inside eukaryotic cells, each carrying out a particular job, are called
Tissues
Organelles
✓
Organs
Organ systems
Correct Answer
Organelles
Organelles are membrane-bound compartments inside eukaryotic cells, such as the nucleus and mitochondria, that perform specific functions. Tissues are groups of whole cells, a level above the cell. Organs are made of several tissues. Organ systems are groups of organs.
Category: Levels of Organization
Question 7
Under the three-domain system, organisms whose cells contain a nucleus belong to which domain?
Bacteria
Archaea
Eukarya
✓
Monera
Correct Answer
Eukarya
Eukarya contains all organisms with nucleated cells, including animals, plants, fungi and protists. Bacteria are prokaryotes, whose cells lack a nucleus. Archaea are also prokaryotes without a nucleus. Monera is an older kingdom name once used for prokaryotes, not one of the three domains.
Category: Classifying Life
Question 8
Which scientist used comparisons of ribosomal RNA sequences to propose that life be divided into three domains?
Carolus Linnaeus
Charles Darwin
Gregor Mendel
Carl Woese
✓
Correct Answer
Carl Woese
Carl Woese compared ribosomal RNA sequences and found that prokaryotes form two very different groups, which led him to propose the domains Bacteria, Archaea and Eukarya. Carolus Linnaeus devised two-part scientific names in the 1700s. Charles Darwin proposed evolution by natural selection. Gregor Mendel discovered the basic patterns of inheritance.
Category: Classifying Life
Question 9
In the binomial system of scientific names, such as Homo sapiens, which two taxonomic levels does the name give?
Genus and species
✓
Family and genus
Kingdom and phylum
Order and class
Correct Answer
Genus and species
A binomial scientific name has two parts: the genus, written first and capitalized, followed by the species name in lowercase, both italicized. Family and genus are not the pair used in the name. Kingdom and phylum are broad groupings never written into a scientific name. Order and class are also broader levels not included in it.
Category: Classifying Life
Question 10
Which taxonomic level is the most specific, the one into which the fewest organisms are grouped?
Genus
Species
✓
Family
Kingdom
Correct Answer
Species
Species is the narrowest category, grouping only organisms most closely related to one another. Genus is one level broader and can contain several species. Family is broader still and contains several genera. Kingdom is one of the broadest levels, just below domain.
Category: Classifying Life
Question 11
Single-celled organisms that lack a nucleus, have genetics distinct from bacteria, and include many members that thrive in extreme environments belong to which domain?
Bacteria
Eukarya
Archaea
✓
Monera
Correct Answer
Archaea
Archaea are prokaryotes that differ genetically and chemically from bacteria, and many of them are extremophiles living in hot springs or very salty water. Bacteria is the other prokaryotic domain, separated from Archaea by genetic differences. Eukarya contains organisms whose cells have a nucleus. Monera is an outdated kingdom name, not a domain.
Category: Classifying Life
Question 12
A scientist who studies the history of life by examining fossils works in which field?
Zoology
Microbiology
Neurobiology
Paleontology
✓
Correct Answer
Paleontology
Paleontology uses fossils to study the history of life on Earth. Zoology is the study of animals in general. Microbiology is the study of microorganisms. Neurobiology is the study of the nervous system.
Category: Branches of Biology
Question 13
A researcher who studies how the brain and nerves are built and how they function works in which field?
Neurobiology
✓
Botany
Ecology
Microbiology
Correct Answer
Neurobiology
Neurobiology, also called neuroscience, studies the structure and function of the nervous system. Botany is the study of plants. Ecology is the study of how organisms interact with each other and their environment. Microbiology is the study of microorganisms.
Category: Branches of Biology
Question 14
Which field applies scientific methods to answer questions related to the law, such as identifying a suspect from DNA left at a crime scene?
Bioethics
Forensic science
✓
Ecology
Taxonomy
Correct Answer
Forensic science
Forensic science applies science to legal questions, including analysis of DNA, blood and other evidence. Bioethics examines the moral questions raised by biological research and technology. Ecology studies organisms and their environment. Taxonomy names and classifies organisms.
Category: Branches of Biology
Question 15
In the general sequence of the scientific method, which step comes right after a scientist proposes a hypothesis?
Making an observation
Reporting the results
Making a prediction
✓
Asking a question
Correct Answer
Making a prediction
Once a hypothesis is proposed, a scientist states what should happen if it is correct, and that prediction is then tested by an experiment. Making an observation comes first and usually prompts the investigation. Reporting the results is the final step. Asking a question comes before the hypothesis is proposed.
Category: Scientific Method
Question 16
A researcher records which brain regions become active in many people doing the same task and then draws a general conclusion. Which type of reasoning is this?
Deductive reasoning
Circular reasoning
Applied reasoning
Inductive reasoning
✓
Correct Answer
Inductive reasoning
Inductive reasoning builds a general conclusion from many specific observations. Deductive reasoning goes the other way, starting with a general principle to predict specific results. Circular reasoning assumes the conclusion it is trying to prove and is not a method of science. Applied reasoning is not a standard type of scientific reasoning.
Category: Reasoning and Explanations
Question 17
A broad explanation of natural phenomena that has been tested and confirmed many times over by many scientists is called a
Scientific theory
✓
Hypothesis
Prediction
Variable
Correct Answer
Scientific theory
A scientific theory, such as the cell theory or the theory of evolution, is a thoroughly tested and well-supported explanation that ties together many observations. A hypothesis is a tentative, testable explanation that has not yet been widely confirmed. A prediction is a specific expected outcome that follows from a hypothesis. A variable is a factor that can change in an experiment.
Category: Reasoning and Explanations
Question 18
In an experiment testing whether added phosphate increases algae growth in ponds, the ponds that receive no added phosphate make up the
Experimental group
Control group
✓
Treatment group
Test group
Correct Answer
Control group
A control group is handled exactly like the experimental group except that it does not receive the factor being tested, which gives a baseline for comparison. The experimental group is the set of ponds that receive phosphate. Treatment group is another name for the group that receives the manipulation. Test group likewise refers to the group being manipulated, not the baseline.
Category: Scientific Method
Question 19
Research aimed at solving a practical problem, such as developing crop plants that resist drought, is an example of
Basic science
Descriptive science
Applied science
✓
Pure science
Correct Answer
Applied science
Applied science uses scientific knowledge to solve specific real-world problems. Basic science seeks understanding for its own sake without a set practical goal. Descriptive science focuses on observing and exploring rather than solving a problem. Pure science is another name for basic science.
Category: Basic and Applied Science
Question 20
Before an article is published in a scientific journal, it is evaluated by qualified experts in the same field. This process is called
Replication
Hypothesis testing
Meta-analysis
Peer review
✓
Correct Answer
Peer review
Peer review is the evaluation of a scientist's work by other experts, who judge whether it is original, significant, logical and thorough before it is published. Replication is the repeating of an experiment to check its results. Hypothesis testing is the experimental work that produces the results in the first place. Meta-analysis is a statistical combination of results from many studies.
Category: Scientific Method