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Biology: Science of Life
Ch.1
(1-1) Characteristics of Life
1.
2.
3.
4.
5.
6.
7.
Organization & Cells
Response to Stimuli
Homeostasis
Metabolism
Growth & Development
Reproduction
Change thru Time
Organization
• Cells: basic unit of life
• Tissues: groups of cells w/ similar functions
– Muscle tissue
• Organs: tissues carry out specialized jobs
– Lung
• Organ Systems: organs that work
together to perform a task
– Respiratory system
Stomach as an Organ Within Digestive System
Figure 41.2
Cell Structure & Function
• Unicellular: 1 cell
– Bacteria
• Multicellular: many cells
– Humans
• Differentiation: cells become
specializedSolution #2
cell specialization and division of labor
Solution #2
cell specialization and division of labor
cell specialization
elaboration of one function and reduction
of others
division of labor
different cell types specialize on different
tasks
Why cells specialize:
"A jack of all trades is master of none"
Doing it all means not doing any one
thing really well.
Example of tradeoff
Fully-featured Swiss
Army knife does
many jobs, but each
tool can be awkward
to use.
Response to Stimuli
• Stimulus: change in the internal or
external environment
– Dilating pupils
Homeostasis
• Stable internal conditions
• Ex:
– Temperature
• Ex: Thermostat
– Water intake
– Food intake
– pH
Metabolism
• Sum of all chemical rxns that take in &
transform E & materials from the
environment
• Photosynthesis: converts light E into
chemical E
• Cellular Respiration: converts organic
cmpds into usable E (ATP)
Growth & Development
• Cell division: formation of 2 cells from
an existing cell
• Development: process by which an
organism grows
– Repeated cell divisions & differentiation
Reproduction
• DNA (deoxyribonucleic acid): large
molecule of hereditary info
• Gene: segment of DNA that contains
instructions for development of a single
trait
• Sexual (2 1) vs. Asexual (1 2)
reproduction
Change Thru Time
• Evolution
(1-2) Themes of Biology
•
3 major themes
1. Diversity & Unity of Life
2. Interdependence of Organisms
3. Evolution of Life
Diversity & Unity of Life
• All living things have in common:
– Genetic code
– Tree of Life (lineages)
• 3 domains
• 6 kingdoms
Interdependence of
Organisms
• Ecology: study of the relationship b/w
organisms & their environment
• Ecosystem: all the biotic & abiotic
(nonliving) components of an
environment
Evolution of Life
• Adaptations: traits that improve ability
to survive & reproduce
• Natural selection: organisms w/
favorable traits reproduce at higher
rates than those w/out such traits
– “Survival of the fittest”
(1-3) Scientific Method
1. Observe
2. Hypothesize
•
Explains observations & data & can be tested
(“if, then”)
3. Predict
4. Experiment
•
Qualitative vs. quantitative (#’s) data
5. Communicate
– Theorize: well-tested explanation of
observations
Experiment Variables
• Control group: standard
– Hunts in light
• Experimental group: identical to control
except 1 factor
– Hunts in dark
• Independent variable: manipulated variable
– Amount of light
• Dependent variable: responding variable
– Distance of owl’s strike
(1-4) Microscopes
• Instrument that produces an enlarged
image of an object
• Ex:
– Light (living)
– Electron (nonliving)
Measurement
• SI: standard system of measurement
used by scientists
• Base units: 7 fundamental SI units
– Length: m
– Mass: kg
– Time: second