CHAPTER 1: EXPLORING LIFE
KEY CONCEPTS
1.1
Biologists explore life fro the microscopic to the global scale.
1.2
Biological system are much more than the sum of its parts.
1.3
Biologists explore life across its great diversity of species.
1.4
Evolution accounts for life’s unity and diversity.
1.5
Biologists use various forms of inquiry to explore life
1.6
A set of themes connects the concepts of biology
INTERACTIVE QUESTIONS
1.1
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
Write a brief description of each of these levels of biological organization.
biosphere – the overall Earth and its ecosystem
ecosystem – living and nonliving aspects
community – all organisms living in a general area
population – all individuals of a single species
organism – an individual living entity
organs and organ systems – compound of many tissues for a common function
tissues – collection of cells
cells – fundamental unit of life
organelles – functional components that make up a cell
molecules – compound of atoms held together by bonds
1.2
How do DNA nucleotides relate to proteins?
The order of nucleotides in a DNA molecule that make up a gene “spells” the
instructions for making a protein with a specific shape and function.
1.3
What types of diverse specialists might be involved in a systems biology team?
a. biologists from all fields, engineers, medical scientists, physicists, chemists,
mathematicians, and computer scientists.
Give examples of how systems biology may impact medical practice or
environmental policy making.
b. in predicting how a particular drug or treatment ma affect various aspects of the body;
in predicting effects on various parts of the ecosystem as CO2 concentration climbs.
1.4
What are the main criteria for separating plants, fungi, and animals into
kingdoms?
They are characterized to a large extent by a large extent by their mode of nutrition.
Plants are photosynthetic, fungi absorb their nutrients from decomposing organic
material, and animals ingest other organisms.
1.5
Describe in your own words Darwin’s theory of natural selection as the
mechanism of evolution.
Most species tend to produce more offspring than can survive. Organisms with heritable
traits best suited to the environment will tend to reproduce more successfully and leave
much more offspring. Over time, favorable adaptations will accumulate in a population.
New species may arise as small populations are exposed to different environments and
natural selection favors different traits.
1.6
How did predators “learn” to avoid coral snakes?
a. Since most encounters with coral snakes are fatal, predators didn’t learn to avoid them.
But predators with genes that somehow made them instinctively avoid coral snakes
would have been more likely to pass on those genes to offspring, gradually adapting the
predator population to the presence of poisonous snakes in their area.
STRUCTURE YOUR KNOWLEDGE
1.a. Cells are the basic unit of life.
b. DNA, codes for proteins.
c. Properties increases as the biological level become larger.
d. Regulates biological systems through positive and negative feedback.
e. materials and energy are exchanged.
f. All organisms require energy, energy flow through ecosystems from sunlight to
chemical energy in producers and consumers to escape as heat.
g. Life is united by descent from a common ancestor, as evidenced by the universal
genetic code. The diversity of life is grouped into three domains.
h. Evolution explains unity and diversity through natural selection.
i. At each level of biological organization, structure and function are correlated.
j. Science includes observation-based discovery and hypothesis based inquiry Hypotheses
must be testable and falsifiable.
k. Technologies are goal-orientated applications of science. Science and technology
provide many benefits yet pose many ethical dilemmas for society.
TEST YOUR KNOWLEDGE
1.d – evolution (p.15)
2.d – the data that should be compared to draw a conclusion must include a control – a
comparison with the number of attacks on model brown snakes. (p.20)
3.b – There may always be alternative hypotheses that might account for the results that
were not tested. (p.23)
4.b – In the birth of a baby, uterine contraction stimulate release of chemicals that
stimulate more uterine contractions. (p.11)
5.a – discovery science – data collection and analysis; deductive reasoning. (p.19)
6.d – one of the proposed kingdom of protists.(p.14)
7.e – all of the above (p.7)
8.c – molecule, organelle, cell, tissue, organ, organism (p.4-5)