Biology 201-Lecture #1
Theme: The study of life can be divided into different levels of biological organization
1. Atoms 2. Molecules and macromolecules 3. Cells 4. Tissues 5. Organs 6. Organism 7. Population 8. Community 9. Ecosystem 10.Biosphere
Theme: There are 7 key features of life
1. Cells and organization 2. Energy use and metabolism 3. Response to environmental change 4. Regulation and homeostasis 5. Growth and development 6. Reproduction 7. Biological evolution
Theme: The Continuity of Life Is Based on Heritable Information in the Form of DNA
Chromosomes contain most of a cell's genetic material in the form of DNA (deoxyribonucleic acid)
Eukaryotic cells vs Prokaryotic cells
Eukaryotes: generally much larger than prokaryotic cells, has a nuclear, contain membrane- bound organelles Prokaryotes: simpler and usually smaller, does not contain a nucleus or other membrane-enclosed organelles
Examples of eukaryotic cells and prokaryotic cells
Eukaryotic: plants, animals, fungi, and all other forms of life Prokaryotic: bacteria and archaea
Theme: Feedback Mechanisms Regulate Biological Systems
Feedback mechanisms allow biological processes to self-regulate
Biologists ask questions such as
How does a single cell develop into an entire complex organism? How does a virus attach to and enter cells? How do living things interact in communities?
Example of a hypothesis
Observation: Your flashlight doesn't work Question: Why doesn't your flashlight work? Hypothesis 1: The batteries are dead Hypothesis 2: The bulb is burnt out
hypothesis-based science
Observations can lead us to ask questions and propose hypothetical explanations called hypotheses
Structure and function are correlated at all levels of biological organization
Seagull as an example of form fitting function
Theme: Cells are an organism's basic units of structure and function
The cell is the lowest level of organization that can perform all activists required for life
Scientists use two main forms of inquiry in their study of nature
The word Science is derived from Latin and means "to know" Inquiry is the search for info and explanation
Hypothesis
a tentative answer to a well-framed question
Genes
a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.
Discovery science
describes natural structures and processes as accurately as possible through careful observation and analysis of data
There are two main types of scientific inquiry:
discovery science and hypothesis-based science
An organism's _______ is its entire set of genetic instruction
genome
Each link of a chain is one of four kinds of chemical building blocks called
nucleotides
A scientific hypothesis leads to predictions that can be tested by
observational or experimental
Qualitative
or descriptions rather than measurements
Quantitative
or recorded measurements, which are sometimes organized into tables and graphs
Types of Data
qualitative and quantitative
DNA
substance of which genes and chromosomes are made
A hypothesis must be
testable and falsifiable
The ability of cells to divide
the basis of all reproduction, growth, and repair of multicellular organisms
What is biology?
the scientific study of life
Each DNA molecule is made up of
two long chains arranged in a double helix
Theories in science
In the context of science, a theory is Broader in scope than a hypothesis General, and can lead to new testable hypotheses Supported by a large body of evidence in comparison to a hypothesis
All cells:
are enclosed by a membrane and use DNA as their genetic information
Negative feedback
as more of a product accumulates, the process that creates it slows and less of the product is produced
Positive feedback
as more of a product accumulates, the process that creates it speeds up and more of the product is produced
