Even though biology is a broad field of study, _______ serves as a central theme that unifies all of biology.
Evolution. Evolutionary theorist Theodosius Dobzhansky wrote that without the light of evolution, biology "becomes a pile of sundry facts some of them interesting or curious but making no meaningful picture as a whole."
The life-supporting environments of Earth constitute the _____.
Biosphere. The biosphere consists of all of the environments on Earth that support life.
What is an ecosystem?
Both the living and nonliving components of the particular area.
Most plants are _____.
Producers. Producers are organisms that can make their own food, as plants do through photosynthesis.
What is the fundamental unit of life?
The cell. The simplest unit of life is the cell, and all organisms are composed of cells.
What is an example of a prokaryotic cell?
Bacteria are prokaryotes.
Gene technology has made it possible for bacteria to express human genes. Why is this possible?
All organisms share a common genetic code. Thus, bacteria are able to read and express human genes
Based on diversity, life is divided into Bacteria, Archaea, and Eukarya. These groupings are called _____.
In what way(s) is the science of biology influencing and changing our culture?
by helping us understand the relevance of evolution to human health, by revealing how mutations in genes can lead to disease, by providing new tools for forensic investigations
What is biology?
the scientific study of life
What is not a property of life?
Populations of organisms rarely change over time.
What are the two main processes that ecosystems depend upon?
nutrient recycling and energy flow
Which of the following is not recycled but is lost from ecosystems?
What is an example of a producer?
An oak tree
Humans are ______.
Which of the following structures can perform all the activities required for life?
Relative to prokaryotic cells, eukaryotic cells are usually ______.
Larger and more complex
Humans are composed of ______ cells.
What name is given to the functional compartments of a cell?
The DNA of a eukaryotic cell is found within the ______.
What are eukaryotic genes composed of?
What is a gene?
a unit of inheritance
The human genome consists of about ______ chemical letters.
More than half of all known species are ______.
Taxonomy is the ______.
naming and classifying of species
How does taxonomy assist biologists?
by categorizing diverse items into smaller and smaller numbers of groups
Which domain(s) consist(s) of prokaryotic cells?
Bacteria and Archaea
Which kingdom of Eukarya consists primarily of unicellular organisms?
A newly discovered multicellular organism obtains food by digesting dead organisms. Such an organism is most likely a member of the kingdom ______.
Members of the kingdom Plantae differ from members of the other kingdoms of Eukarya in that most members of the kingdom Plantae ______.
Produce their own food
In his book The Origin of Species, Darwin argued that species living today descended from a succession of ancestral species. What mechanism did Darwin propose to explain how evolution occurs?
What mechanism explains why polar bears are white and bears found farther south have a darker color?
What is the basis of natural selection?
unequal reproductive success
Which of these scenarios is the result of natural selection?
the proliferation of pesticide-resistant insects
The branch of biology that explains both the diversity and the unity of life is ______.
Which of these is most closely associated with Darwin?