Ch 1 Introducing biology
Exercise
Section 1.1
Level 1 (p. 1-19)
1
C
Section 1.2
Level 1 (p. 1-19)
2
C
Level 2 (p. 1-19)
3
a No
1
The death rates of childbed fever were different in the two clinics. /
If fear of hospitalization caused childbed fever, the death rates would have been similar
in the two clinics.
1
b i
The death rate of childbed fever in a clinic in which doctors handle deliveries
straight after dissecting dead bodies.
1
ii The death rate of childbed fever would be lower in the clinic in which doctors
wash their hands before handling deliveries.
1
Section 1.3
Level 2 (p. 1-19)
4
a To prevent the exchange of any materials between the soil and the environment. 1
b i
Plants grow by absorbing materials from the soil.
1
ii The increase in mass of the tree would be equal to the decrease in mass of the soil.
1
iii The hypothesis is falsified
1
because the increase in mass of the tree was much higher than the decrease in
mass of the soil.
1
c
Science advances through reasonable skepticism.
1
Van Helmont questioned the general belief that plants grew by absorbing materials
from soil.
1
(or other reasonable answers)
Reading to learn (p. 1-20)
1
2
If the S-shaped neck of a flask was broken to allow microorganisms on dust particles to
reach the boiled broth, then microorganisms would appear in the boiled broth.
1
It was used to show that the result of the experiment was due to the presence of
microorganisms in the air.
1
3
Nature of science
Science is affected by the
technology and the types of
equipment available at the time.
Scientists have to explore using
different techniques and methods
to find out a good solution to a
problem.
Scientific knowledge is tentative
and subject to change.
Elaboration
The invention of microscopes
helped the discovery of
microorganisms in the air.
1
Pasteur used flasks with an Sshaped neck to allow air but not
microorganisms to enter the
flasks.
1
Scientists no longer think
microorganisms arise from nonliving things by spontaneous
generation.
1