biology EXAM #1 pt. 1 Flashcards
Science :
- the investigation of rational concepts that can be evaluated
Hypothesis :
a proposed explanation for an observed phenomenon
Theory :
- a hypothesis that is consistent with all available evidence
Biology :
Is the scientific study of life by observations and experimentation.
The study of life:
Extends from the microscope scale of molecules and cells to the global scale of the entire living planet
Biologists ask questions such as:
How does a single cell develop into an organism?
How does the human mind work?
How do living things interact in communities?
Life is :
recognized by what living things do
There are five unifying themes:
-Organization
-Information
-Energy and matter
-Interactions
-Evolution
The hierarchy of life:
Extends through many levels of biological organization
Order of biggest unit of structure to smallest
- Biosphere
- Ecosystems
- Communities
- Populations
- Organisms
- Organs and Organ systems
- Tissues
- Cells
- Organelles
- Molecules
The cell :
– An organism’s basic unit of structure and function
-Is the lowest level of organization that can perform all activities required for life
Every cell is enclosed:
enclosed by a membrane that regulates passage of materials between the cell and its environment
All cells share certain characteristics:
- They are all enclosed by a membrane
- They all use DNA as genetic information
There are two main forms of cells:
Eukaryotic
Prokaryotic
Eukaryotic cells:
Are subdivided by internal membranes into various membrane-enclosed organelles
-nucleus (contains DNA)
Prokaryotic cells:
Lack the kinds of membrane-enclosed organelles found in eukaryotic cells
-DNA (no nucleus)
Cells contain chromosomes made partly:
of DNA, the substance of genes
Which program the cells’ production of proteins and transmit information from parents to offspring
Each chromosome has:
one long DNA molecule with hundreds or thousands of genes
Genes :
encode:
units of?
-encode information for building the molecules synthesized within the cell
-units of inheritance
DNA controls:
controls the development and maintenance of organisms
Genes control:
process-
protein production indirectly.
DNA is transcribed into RNA, which is then translated into a protein
Gene expression:
is the process of converting information from gene to cellular product
Interactions between components that make up living organisms are:
components:-organs, tissues, cells, and molecules
are: crucial to their smooth operation
Cells are able to cooordinate:
coordinate various chemical pathways through a mechanism called feedback