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Biology 221 Notes Exam I. Powerpoint 1. Biolog y is the study of life. There are currently millions of extant (living) species (see below for taxonomic levels). Properties that are shared by all living organisms. Order.
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Biology 221 Notes Exam I Powerpoint 1
Biology is the study of life There are currently millions of extant (living) species (see below for taxonomic levels)
Order Each organism possesses a highly ordered structure even if they may seem simplistic (like prokaryotic cells or single-celled eukaryotic organisms).
Growth, development, and reproduction All reproduce and pass their DNA from parent to offspring. DNA then directs the pattern of growth and development.
Response to stimuli (sensitivity) All organisms respond to internal and external stimuli.
Energy processing All living organisms obtain and then transform energy into a usable form (ATP).
Homeostasis All organisms are capable of maintaining a relatively stable internal environment. This is accomplished by feedback mechanisms
Evolutionary adaptation Living organisms adapt to their environments.
Regulation Living organisms have regulatory mechanisms that function in the coordination of the organism’s functions.
Structural levels of Biological Organization is based on structural levels with each level building on the levels below it. Note that with each step upward in the hierarchy that there are new properties that are not present at the previous level (emergent properties). Emergent properties are due to the arrangement and interactions of parts as complexity increases
The Eight Unifying Themes of Biology (Reece et al., 2011). Please note that different textbooks may organize these a bit differently.
Emergent Properties are those that are unique to a higher level of organization (this is also consistent with some non-living objects). 1. Reductionism is the study of components of complex “systems”. It makes experimentation easier to look at individual parts instead of the whole system. 2. Systems biology models whole systems by focusing on the interactions of the parts.
Interactions between organisms and the physical environment Elephant and other animals eat leaves and fruit of tree, leaves of tree convert sunlight energy to energy in glucose (photosynthesis), nutrients are cycled etc.
Energy and energy transfer are necessary for all living organisms (also a property of living organisms).
Form fits function Correlation of structure and function The cheetah has long legs, large lung capacity and other structures allow it to attain great speed.
Cell The cell is the basic unit of life and all cells have a membrane and DNA
DNA (deoxyribonucleic acid) is passed from parent cells to daughter cells and from parents to their
Feedback mechanisms that lead to regulation of cellular and multicellular activities
Evolution The core theme of biology is Evolution. Theories are much broader in scope than hypotheses. Thus theories are comprehensive and are supported by an accumulation of extensive and varied evidence.
Taxonomic levels Throughout history humans have attempted to categorize the different species into different groups.
First there were two Kingdoms of Life Linneaus suggested two kingdoms based on the ability of the organisms to move: Plants that did not move and Animals that did. Ernst Haeckel suggested creating a third kingdom Protista
Then there were Five Kingdoms of Life More recently, biologists have attempted to categorize organisms according to the phylogenetic (actual, historic) relationships among them. In 1969, Whittaker proposed the five Kingdom system (Monera, Protista, Fungi, Plantae, and Animalia).
Now there are Three Domains There are currently three domains (Bacteria, Archaea, and Eukarya) The Domain Eukarya is then divided into multiple kingdoms (four or more).
Kingdoms are subdivided into increasingly inclusive taxa. In general Kingdoms are divided into various Phlya (singular phylum), Phyla are divided into multiple Classes, Classes are divided into Orders, Orders are divided into Families and Families are divided Genera (singular Genus), and a genus is divided into multiple species.
All species have a two-part name (Linneaus) that consists of the genus and species. The first letter of the Genus name is always capitalized and the first letter of the species name is lower case. The name is italicized or underlined because it is derived from Latin UrsasamericanusOR Ursasamericanus
Science as a process Scientific discoveries are basically made by using one of two methodologies.
Discovery science is also known as descriptive science Involves observing and documenting phenomena without experimentation. A recent example is the sequencing of the human genome. Conclusions are often based on inductive reasoning. Inductive reasoning uses specific observations to construct general scientific principles.
Hypo-deductive Science. Based on hypothesis testing and deductive reasoning. Hypotheses are simply educated guesses. Null hypotheses are those that suggest that there are no differences between the control and the experimental groups whereas alternative hypotheses are those that suggest a difference. Deductive reasoning is the opposite of inductive reasoning; from general premises, one extrapolates to the specific results that are expected if the premises are true. In general the predictions are the potential outcomes of the experiments that should be expected if a hypothesis is correct.
ECOLOGY the study of interactions between organisms and their environments
Organismal ecology includes various sub disciplines of biology (e.g., physiology) dealing with the organism and its natural history.
Population ecology Population (a group consisting of individuals of the same species living in a given area) ecology deals with the factors that affect the population (specifically its size and changes over time)
Community Ecology Community (the different populations of the different species living in a given area) ecology is related to the interactions of the different species that make up the community
Ecosystem Ecology Ecosystem (the biotic and abiotic factors in a given area) ecology is the study of the living organisms and the biogeochemical cycles and energy flow that affect them.
Landscape Ecology Landscape ecology involves the different types of patches (e.g., corridor of trees lining a river flowing through a sparsely vegetated plain) and research focuses on the factors controlling the exchanges of energy, materials, and organisms among the ecosystem patches.
Biosphere (the habitable portion of the Earth). Global ecology is the study of the biosphere. Global studies are difficult in that there is no control. For example it is difficult to study the specific causes and their exact impacts on Global Climate Change. However, evidence does suggest and most scientists agree that the climate is currently changing and that human activities play a role in that change.
Abiotic Factors and Climate Abiotic factors and climate (the long term prevailing weather conditions of a given area). Factors that impact climate (moisture and temperature in particular):
Sunlight intensity Sunlight intensity varies with latitude; the most direct sunlight occurs at the equator.
Season Season also affects the sunlight intensity (the planet changes position)
Air circulation Air circulation affects precipitation
