Chapter 1 - The Science of Biology Flashcards
Biology
the study of living things, the science of life
7 characteristics shared by living systems
- Cellular organization
- Ordered complexity
- Sensitivity
- Growth, development, and reproduction
- Energy utilization
- Homeostasis
- Evolutionary adaptation
Living systems hierarchal organization
*Cellular level -
atoms (fundamental elements of matter),
molecules (clusters of atoms),
macromolecules (carbohydrate, protein, lipid, nucleic acid),
organelle (complex biological molecules with membrane-bounded units),
cell (basic unit of life)
*Organismal level -
tissue (groups of similar cells that act as a functional unit),
organ (body structures composed of several different tissues),
organ system (groups of organs),
organism
*Population level -
population (group of organisms of the same species living in the same place),
species (particular kind of organism),
community (all the populations of different species living together in one place),
ecosystem (biological community and the physical habitat within which it lives together),
biosphere (entire planet)
Emergent properties
Novel properties arising from the way in which component interact. Often cannot be deduced solely from knowledge of the individual components
Ex. Heart
Convergent evolution
The independent development of similar structures in organisms that are not directly related; often found in organisms living in similar environments (biomes)
Nature of Science
- Science deals with observations and measurements
* If it can’t be observed or measured it is out of the realm of science
2 main scientific approaches
- Discovery science
* Hypothesis driven science (problem solving)
Discovery Science
Verifiable observations and measurements
- Data collection and analysis
- Classification of organisms
- Decoding the human genome
- Not necessarily an experiment
Hypothesis driven science (problem solving)
Scientific method is used
Scientific method
An organized manner to examine the natural world
Scientific method steps
- Observations
- Hypothesis
- Experiment
- Data analysis
- Results and conclusions
Deductive reasoning
Applies general principles to predict specific results
Ex. if all mammals by definition have hair, and you find an animal that does not have hair, then you may conclude that this animal is not a mammal
Inductive reasoning
Uses specific observations to construct general scientific principles
Ex. if poodles have hair, and terries have hair, and every dog that you observe has hair, then you may conclude that all dogs have hair
Limitations to the scientific method
- Hypothesis cannot be proven
- Repeated many times
- Bias - avoid biases
Theory
- Proposed explanation for some natural phenomenon, often based on some general principle
- Body of interconnected concepts, supported by scientific reasoning and experimental evidence, that explains the facts in some area of study
Reductionism
philosophical approach to understand a complex system by reducing it to its working parts
Basic research
intended to extend the boundaries of what we know, usually done at a university supported by grants, provides the scientific foundation for applied research
Applied research
information generated by basic research contributes to the growing body of scientific knowledge. Industrial research, manufacture of good additives, the creation of new drugs, or the testing of environmental quality
Charles Robert Darwin
English naturalist, wrote the book On the Origin of Species by Means of Natural Selection
Observations by Darwin
- Organisms are similar to fossils
- Organisms are similar to coastal species
- Closely related organisms differ slightly
Charles Lyell
Earth is old
Thomas Malthus
Populations of plants and animals tend to increase geometrically while humans are able to increase their food supply only arithmetically. Population growth, survival of the fittest
Artificial selection
Change in the genetic structure of populations due to selective breeding by humans
Natural selection
The differential reproduction of genotypes; caused by factors in the environment, leads to evolutionary change
- Struggle for existence
- Best adaptations are passed to successive generations
- Overtime the genetic make-up of a population will change
Alfred Wallace
- 1858 sent essay to Darwin to review
- Similar to Darwin’s hypothesis
- Joint presentation of ideas at a seminar
- 1859 Darwin’s book published
Evolution after Darwin
Supporting evidence
- Fossils - would yield intermediate links between the great groups of organisms. Ex. fishes and amphibians, reptiles and birds
- Age of earth - evidence of rates of radioactive decay show the Earth was formed 4.5 billion years ago
- Heredity
- Comparative anatomy - homologous and analogous structures
- Molecular evidence - comparing genomes, Ex. vertebrates that are more distantly related to humans have a greater number of amino acid differences in the hemoglobin polypeptide
Unifying Themes of Biology
- Organization of life - cell theory
- Continuity of life - inheritance
- Diversity of life - evolutionary change
- Unity of life - evolutionary conservation
- Structure and function
Cellular organization
Cell theory
- all organisms are composed of cells, can be unicellular or multicellular
- cells are basic unit of life
- cells arise from pre-existing cells
Ordered complexity
All living things are both complex and highly ordered.
Ex. Human body is composed of many different kinds of cells, each containing many complex molecular structures. Many nonliving things may also be complex, but they do not exhibit this degree of ordered complexity.
Sensitivity
All organisms respond to stimuli.
Ex. Plants grow toward a source of light, and the pupils of your eyes dilate when you walk into a dark room.
Growth, development, and reproduction
All organisms are capable of growing and reproducing, and they all possess hereditary molecules that are passed to their offspring, ensuring that the offspring are of the same species.
Energy utilization
All organisms take in energy and use it to perform many kinds of work.
Ex. Every muscle in your body is powered with energy you obtain from the food you eat.
Homeostasis
All organisms maintain relatively constant internal conditions that are different from their environment.
Ex. Regulation of body temperature 98.6 ‘F, pH, blood pressure, etc.
Evolutionary adaptation
All organisms interact with other organisms and the nonliving environment in ways that influence their survival, and as a consequence, organisms evolve adaptations to their environments
Ex. Darwin’s finches, Caribbean anoles
The Sun
The complexity of living systems is made possible by this constant source of energy
Darwin’s hypothesis
Evolution occurs because of natural selection
Analogous Structure
Structures that have similar function but different evolutionary origins
Homologous Structures
Bones that have the same evolutionary origin, but they now differ in structure and function
Phylogenetic Tree
The pattern of descent. It represents the evolutionary history of the gene, its “family tree”. Molecular phylogenetic trees agree well with those derived from the fossil record, which is strong direct evidence of evolution
Cell Theory
One of the basic ideas in biology, the foundation for understanding the reproduction and growth of all organisms. All cells come from preexisting cells and all living organisms consist of cells.
DNA
Deoxyribonucleic acid, a long, cable like molecule that is formed from tow long chains of building blocks, called nucleotides wound around each other. Four different nucleotides are found in DNA and the sequence in which they occur encodes the cell’s information.
Gene
A discrete unit of information, made up of several hundred to many thousand nucleotides
Genome
The entire set of DNA instructions that specifies a cell
Function in molecules and larger macromolecular complexes, is dependent on their?
Structure
The relationship between structure and function
Allows similar structures to be used to infer possible similar functions; the knowledge also gives clues as to what kinds of structures may be involved in a process if we know about the functionality.
Biologists divide life’s great diversity into three great groups, called domains.
Bacteria, Archaea, and Eukarya
The domains Bacteria and Archaea are composed of?
Single-celled organisms with little internal structure (prokaryotes)
The domain Eukarya is made up of?
organisms composed of complex, organized cell or multiple complex cells (eukaryotes)
Eukarya are made up of how many groups and are called what?
4 main groups; kingdoms
Eukarya are four main groups called kingdoms, what are they called?
Plantae, Fungi, Animalia, Protista
