Themes in the Study of Life – Flashcards

Evolution is the process of change that has transformed life on Earth from its earliest beginnings to the diversity of organisms living today. Evolution is the fundamental organizing principle of biology and the core theme of this book. Example: The mother-of-pearl plant has adapted to its dry environment with its fleshy, succulent leaves, allowing the plant to conserve water.

Biology is the scientific study of life. Biology is a quest, an ongoing inquiry about the nature of life. Posing questions about the living world and seeking science based answers (scientific inquiry) are central to the study of biology.

We recognize life by what living things do. The living world is wondrously varied. Properties of Life: Order, Regulation, Reproduction, Evolutionary Adaptations, Energy Processing, Response to the Environment, & Growth and Development.

1) New properties emerge at each level in the biological hierarchy. 2) Organisms interact with other organisms and the physical environment. 3) Life requires energy transfer and transformation. 4) Structure and function are correlated at all levels of biological organization. 5) The cell is an organism's basic unit of structure and function. 6) The continuity of life is based on heritable information in the form of DNA. 7) Feedback mechanisms regulate biological systems. 8) Evolution accounts for the unity and diversity of life. 9) Scientific knowledge is based on ongoing research.

Emergent properties are due to the arrangement and interactions of parts as complexity increases. Novel properties emerge at each step in the biological hierarchy, properties that were not present at the preceding level. Example(s): Photosynthesis, thoughts and memories, recycling of chemical nutrients.

Reductionism is the approach of reducing complex systems to simpler components that are more manageable to study. Reductionism is a powerful strategy in biology. We can't fully explain a higher level of order by breaking it down into its parts, but something as complex as an organism can't be analyzed without taking it apart.

Systems biology is an approach that attempts to model the dynamic behavior of whole biological systems based on a study of the interactions among the system's parts. Successful models enable biologists to predict how a change in one or more variables will affect other components and the whole system. Example: How might a gradual increase in atmospheric carbon dioxide alter ecosystems and the entire biosphere?

1) The Biosphere: all life on earth (earth). 2) Ecosystems: all of the living things in a particular area, along with all of the nonliving components of the environment with which life interacts (a deciduous forest). 3) Communities: The entire array of organ-isms inhabiting a particular ecosystem is called abiological community. Each form of life is called a species (living things within a particular forest). A set of populations that inhabit a particular area make up a community. 4) Populations: all of the individuals of a species living within the bounds of a specified area (white-tailed deer). 5) Organisms: individual living things (a single white-tailed deer). 6) Organs and Organ Systems: an organ is a body part that carries out a particular function. Organs are arranged into organ systems to work together towards a larger function (brain: nervous system). 7) Tissues: each tissue is made up of a group of cells that work together to form a specialized function (photosynthetic tissue). 8) Cells: the cell is life's fundamental unit of structure and function. Some organisms are single-celled, while others are multicellular (muscle cells, nerve cells). 9) Organelles: the various functional components present in cells (chloroplasts). 10) Molecules: a chemical structure consisting of two or more chemical units called atoms (chlorophyll). (M.O.C.T.O.Os.O.P.C.E.B)

Interactions between humans and the environment sometimes have drastic consequences, such as global climate change, which has already had dire effects on life forms and habitats all over planet earth (greenhouse effect, CO2).

Consumers are organisms, such as animals, that feed on producers and other consumers. An animal uses sugar (chemical nutrients) to power movement (kinetic energy). In contrast with chemical nutrients, which are recycled, energy usually enters as light and exits as heat.

Every cell is enclosed by a membrane that regulates the passage of material between the cell and its surroundings. And every cell uses DNA as its genetic information.

A eukaryotic cell is subdivided by internal membranes into various membrane-enclosed organelles. The nucleus contains the cells genetic information, or DNA. The other organelles (chloroplast) are located in the cytoplasm.

Prokaryotic cells are much simpler, and generally much smaller than eukaryotic cells. Prokaryotic cells lack membrane-bounded organelles and the DNA is not separated from the rest of the cell.

The chromosomes (inside the dividing cell) have almost all of the cell's genetic material, its DNA. DNA is the substance of genes, the units of inheritance that transmit information from parents to offspring (genes, DNA, chromosome).

Genes encode the information necessary to build other molecules in the cell, most notably proteins.

The molecular structure of DNA accounts for its ability to store information. Each DNA molecule is made up of two long chains, called strands, arranged in a double helix. Each chain is made up of four kinds of chemical building blocks called nu-cleotides, abbreviated A, T, C, and G.

DNA provides the blueprints for making proteins, and proteins are the main players in building and maintaining the cell and carrying out its activities.

Enzymes, which catalyze (speed up) specific chemical reactions, are mostly proteins and are crucial to all cells.

The DNA of genes controls protein production indirectly, using a related kind of molecule called RNA as an intermediary. The sequence of nucleotides along a gene is transcribed into RNA, which is then translated into a specific protein with a unique shape and function. This entire process, by which the information in a gene directs the production of a cellular product, is called gene expression (DNA, RNA, Protein).

The entire "library" of genetic instructions that an organism inherits is called its genome.

Genomics refers to a systems approach studying whole sets of genes as well as comparing genomes between species. Researchers aim to discover how the activities of the myriad proteins encoded by the DNA are coordinated in cells and whole organisms.

1) "high-throughput" technology, tools that can analyze biological materials very rapidly and produce enormous amounts of data 2) bioinformatics or the use of computational tools to store, organize, and analyze the huge volume of data that result from high-throughput methods 3) interdisciplinary research teams

Though less common than processes regulated by negative feedback, there are also many biological processes regulated by positive feedback, in which an end product speeds up its own production (blood clotting).

The most common form of regulation in living systems is negative feedback, in which accumulation of an end product of a process slows that process (ATP).

We can explain traits shared by two organisms with the idea that they have descended from a common ancestor, and we can account for differences with the idea that heritable changes have occurred along the way. Diversity is a hallmark of life.

Taxonomy is the branch of biology that names and classifies species and formalizes this ordering of species into groups of increasing breadth, based on the degree to which they share characteristics.

Although there is disagreement at the kingdom level, there is consensus among biologists of the three domains: bacteria (prokaryotic), archaea (prokaryotic), and eukarya (eukaryotic). Domain eukarya includes kingdoms plantae, fungi and animal which are distinguished by means of nutrition. Protists are single-celled eukaryotes.

Science is a way of knowing, an approach to understand the natural world.

At the heart of science is inquiry, a search for information and explanation, often focusing on specific questions. The scientific process of inquiry includes making observations, forming logical hypotheses, and testing them.

Scientists describe natural structures and processes as accurately as possible through careful observation and analysis of data. Observation is the use of the senses to gather information.

Recorded observations are called data. Data are items of information on which scientific inquiry is based (quantitative and qualitative).

Through induction, we derive generalizations from a large number of specific observations.

A hypothesis is a tenative answer to a well-framed question, or an explanation on trail. A hypothesis can be tested. A hypothesis must be testable and falsifiable.

Deductive reasoning is generally used after the hypothesis has been developed and involves logic that flows in the opposite direction, from the general to the specific (if...then).