Transcript Answers to HW Questions

C&C
p.14
1 – Describe how evidence and hypotheses are
characteristics of science.
The scientific method involves making hypotheses (testable
proposals) that seek to explain how natural phenomena occur. A
hypothesis must be consistent with available evidence (data)
that pertain to the phenomena being studied.
2 – How does a hypothesis differ from a theory? Give a
concrete example of each.
A hypothesis is a testable question about an observation and
may be stated in an “if…then” format. A theory is a model that is
supported by data from many testable hypotheses and for which
little, if any, opposing data have been found
C&C
p.14
3 – Describe the theory of evolution by
means of natural selection.
The theory of evolution recognizes variation in all
populations of organisms. The environment
interacts with the population in such a way that
individuals better adapted to the environment will
produce more offspring than those who are less fit.
Over time, this natural selection produces
organisms well suited to their environment.
C&C
p. 14
4 – Describe how natural selection operates on
species.
Natural selection continuously culls individuals that are
less fit and results in species that are highly adapted
to their environment.
5 – How do Lamarck’s theory and Darwin’s theory
differ?
Lamarck’s theory assumes that characteristics acquired
during an individual’s lifetime can be passed on to the
next generation. In this view, inherited traits are
based on “need.” Darwin’s theory was based on the
interaction between inherited traits and their fitness in
the environment.
RI
p. 18
4 – How are hypotheses, observations, and experiments
used in science?
Hypotheses are the questions being tested;
observations gather data about the hypotheses and
contribute to the design of experiments used to
obtain answers to the questions.
6 – How did Darwin use the methods of science develop
his theory?
Darwin made many observations during his voyage
on the Beagle and after his return to England. He
developed a hypothesis of how species change over
time and examined his data to see whether or not they
supported the hypothesis. Only after much study and
deliberation did he conclude that evolution occurs and
publish his results.
RI
p. 18
7 – Why were Lamarck’s ideas rejected? On what
assumptions were his ideas based?
Lamarck’s hypothesis was invalid because
his basic assumption of inheritance of acquired
characteristics was proved incorrect.
8 – Compare and contrast a hypothesis and a
theory?
A hypothesis is an educated guess that tries
to explain a natural phenomenon. A theory is a
tested model that explains and organized
hypotheses and experiments. Theories are
supported by many data.
RI
p. 18
9 – What is the relationship between natural selection and
the environment?
The environment supplies conditions that determine
which characteristics will enhance an individual’s chance
of survival and reproduction
10- What are the characteristics of science, and how does
it differ from pseudoscience?
Science is based on observations and experiments
that are repeatable, verifiable, and refutable.
Pseudoscience often is based on matters of faith that
cannot be examined by observations and experiments or
cannot be refuted.
UC
p. 19
2- Some animals, such as the arctic fox and
the ptarmigan (a bird), change the color of
their fur or feathers from summer to winter.
Relate these changes to natural selection.
Animals that change color to white during the
winter are protected from predators by their
color, and more will survive to reproduce than
will animals with colors that stand out in the
snow.
UC
p. 19
3- Darwin stated that a struggle for existence-for
adequate food, space, water, and so on-occurs
in all species. Is this true for the human species
as well? Give concrete examples to substantiate
your answer.
Humans sometimes must struggle for food,
space, and water just as other species must.
Various examples of the struggle for
existence, especially in developing countries,
could be cited
UC
p. 19
9- Imagine a long-legged wolf and a short-legged wolf.
Relate the length of their legs to their ability to catch
enough rabbits to feed their offspring. Would one wolf be
more successful than the other in providing enough food
for its offspring to survive? Would it be advantageous to
have long legs?
Answers may vary
Long-legged wolves may have an advantage over
short-legged wolves in a snowy environment because
their legs will allow them to stand above the deep snow
thus allowing the wolf to track down the rabbit more
easily.