Bio Test Study.docx - • Common Properties of Living Things ...

• Common Properties of Living Things
(non-living things may have some, but not all)
1. Made up of cells (one cell or multiple cells): basic building block of
life
2. Metabolisms (uptake and use of matter and energy, chemical
reactions within cells)
3. Homeostasis and regulation: Maintain constant internal environment
4. Perceive and respond to environment
5. Grow and develop during their lifetime
6. Reproduce
7. Inherit information: DNA contains information for growth and
unction, is transmitted
during reproduction to offspring
8. Adaptation: have characteristics that are fine-tuned to environment
the organism lives in
9. Evolve over generations: results in changes of genetic information
present in the
population
10. Shows order: complex organization, different levels of organization,
distinct properties or
features associated with different levels of organization
Levels of Organization
o Atom
o Molecule
o Sub-cellular structure: organelles
o Cell (some cells are organisms): basic building block of life
o Tissue
o Organ
o Organ system

o Organism: an individual living being
o Population
o (Ecological) Community
o Ecosystem
o Biosphere
Scientific method (standardized approach used by scientists to study
the world)
Steps:
1. Observation
2. Question
3. Hypothesis (Potential answer)
Null Hypothesis: Observed patterns are due to chance
Alternative Hypothesis: provides an explanation for the observed
pattern that is
different from the null hypothesis
4. Test of hypothesis
Ideally with controlled experiment
Goal of experiment: reject/disprove the hypothesis
5. Results:
6. Conclusion: interpretation of results
Approaches to test hypotheses:
• Experiment (experimental studies):
o Each experiment includes:
▪ Explanatory variable (X) that is manipulated by the
researcher [suspected cause]
▪ Response variable (Y) that is measured by the researcher
[suspected effect]

▪ Controls: e.g. all organisms in experiments have the same
or similar characteristics and experience the same
environment
o Advantage: cause and effect can be identified with high certainty
• Observational studies:
o Explanatory variable (X) is not manipulated by researcher;
o Response variable (Y) that is measured by the researcher
o Control of condition/environment difficult
o Advantage:
▪ Used when experiment not possible or not ethical
▪ Cheaper than experiment
▪ often used to investigate rare outcomes (e.g., detection of
unusual side effects of new drugs)
o Disadvantage: cause and effect cannot always be identified with
certainty
• Simulations/Modelling:
o Used to understand how, for example, an organism or an
ecosystem works
▪ A theoretical model of the organism or the ecosystem is
produced.
▪ Simulations change systematically characteristics of the
model of the organism or ecosystems
▪ Based on results of simulations, make predication how the
organism or ecosystems will change under specific
conditions.