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BSC 1010C Biology I
Themes in the Study of Life
Chapter 1
Objectives
Distinguish among the three domains of life.
Distinguish between the Levels of Biological Organization.
Note the differences in the following terms: inductive reasoning and
deductive reasoning, science and technology.
Know the properties of Life.
Unifying Themes in Biology
New properties emerge at each level in the Biological Hierarchy
Organisms interact with other organisms and the physical environment
Life requires energy transfer and transformation
Structure and Function are correlated at all levels of biological organization
The cell is an organism's basic unit of structure and function
The continuity of life is based on heritable information (DNA)
Feedback mechanisms regulate biological systems
Evolution accounts for the unity and diversity of life
In studying nature, scientists make observations and then form and test
hypothesis
Science benefits from cooperative approach and diverse viewpoints.
Biology
Biology is the scientific study of life
-As we are aware life is very complex
Biology is a collection of facts and concepts structured within theories and
organizing principles.
The properties and processes of life
include:
-order
-Evolutionary adaptation
-response to the environment
-regulation
-energy processing
-growth and development
-reproduction
Properties of Life
Levels of Biological Organization
The Biosphere
-consists of all life on Earth and all the places where life exists.
Ecosystems
-consist of all the living things in a particular area along with nonliving components in which life
interacts
Communities
-organisms inhabiting a particular ecosystem
Populations
-consists of all the individuals of a species living in a specified area
Organisms
-individual living things
Organs and Organ Systems
-an organ is a body part that carries out a particular function in the body. An organ system is a
team of organs that cooperate in a larger function.
Tissues
-a group of cells that work together, performing a specialized function.
Cells
-life's fundamental unit of structure and function
Organelles
-functional components present on cells
Molecules
-a chemical structure consisting of two or more atoms
Atom
-the smallest unit of matter that retains the properties of an element
Hierarchy of Organization
Organisms Interact with the Physical Environment
In an ecosystem, each organism interacts continuously
with its environment, which includes both other
organisms and physical factors
Both the organism and the environment are affected by
the interactions between them
-Ex. Plants
Energy flow in ecosystems
Nutrient cycling
Structure and Function are Correlated
Form fits function which you'll recognize from everyday life.
How a device works is correlated with its structure
-Ex. Gull's Wing
-The shape of a bird's wings and the structure of its bones
makes flight possible
The Cell is An Organisms Basic
Unit of Structure and Function
The cell is the lowest level of organization that can perform all
activities required for life
Two types of cells: Eukaryotic and Prokaryotic cells
Eukaryotic:
-usually larger and more complex
-has a nucleus (holds DNA)
-membrane-enclosed organelles
Prokaryotic:
-usually smaller and simpler
-no nucleus
No membrane-bound organelles
The Continuity of Life Is Based on Heritable Information
Cells contain structures called chromosomes
The chromosomes have almost all of the cell's genetic material, it's DNA
DNA is short for Deoxyribonucleic Acid
DNA is the substance of genes, the units of inheritance that transmit information from parents to offspring
The molecular structure of DNA accounts for its ability to store information
DNA
Feedback Mechanisms Regulate Biological Systems
Organisms obtain energy by regulated chemical reactions
-regulation is carried out by enzymes
-each type of enzyme catalyzes a specific chemical reaction
Many biological processes self regulate by a mechanism
called feedback
-Negative feedback slows the process
-Positive feedback speeds up its own production
Classifying the Diversity of Life
Diversity is a hallmark of life
Biologists have identified and named about 1.8 million
species
Taxonomy, the branch of biology that names and
classifies species
Three domains of Life:
-Bacteria
Archaea
Eukarya
-Protists
-Fungi
-Plants
-Animals
EVOLUTION
Evolution accounts for the unity and diversity of life and also
for the match of organisms to their environments.
Common characteristics are the result of common ancestry
Charles Darwin is known as the “Father of Evolution”
Charles Darwin wrote On the Origin of Species
-Had two main points
*contemporary species arose from a succession of ancestors
(descent with modification)
*natural selection
Natural Selection
Descent with Modification
Scientific Method
Science is a way of knowing- an approach to understanding the natural
world
Inquiry is a search for information and explanations, often focusing on
specific questions
Combines two types of investigative approaches: inductive and deductive
reasoning.
Inductive reasoning
-depends on specific observations and data analysis
-leads to specific generalized conclusion derived from a large number of
specific observations
Deductive Reasoning
-generally used after the hypothesis has been developed
*Hypothesis is a tentative answer to a well-framed question
-from a general premise we get specific results
-If....... then logic
These two approaches is called the scientific method
Science, Technology and Society
The biology community is part of society at large.
Science is a social activity
The work of each scientist builds on the work of others that have
come before
Scientists must be able to repeat each other's results, so integrity is
key.
Science and technology are associated
Technology is a method or device that applies scientific knowledge
for some specific purpose that affects society
Diversity among scientists promotes progress in science