500 Flashcards Praxis Biology 5236 Exam
Define a scientific hypothesis and explain how it differs from
a scientific theory.
A scientific hypothesis is a testable and falsifiable
explanation for an observation or phenomenon. A scientific
theory is a broad, well-supported explanation backed by
repeated experimentation and extensive evidence. A
hypothesis may become supported by evidence, but
theories do not "graduate" into laws.
A student claims, "Plants grow faster because music makes
them happy." Identify the problem with this statement
scientifically.
The statement is not scientifically rigorous because "happy"
is subjective and not measurable. Scientific explanations
require measurable variables such as growth rate, light
exposure, or hormone activity.
In an experiment, the variable intentionally changed by the
researcher is called the __________ variable.
Independent variable.
Page 1 of 110
,500 Flashcards Praxis Biology 5236 Exam
In a bacterial growth experiment, nutrient concentration is
changed while temperature is kept constant. Identify the
dependent variable.
The dependent variable is bacterial growth because it is the
measured response affected by nutrient concentration.
Explain why scientific knowledge changes over time.
Scientific knowledge changes because new observations,
technologies, and experimental evidence may refine or
replace previous explanations. Science is self-correcting.
Scientific laws explain why natural phenomena occur. Give
reasoning.
False. Scientific laws describe patterns or relationships
observed in nature, while scientific theories explain why
those phenomena occur.
A biology student records mass as 12.450 g on a balance
that only measures to 0.01 g. What is the error?
The student used too many significant figures. The value
should be reported as 12.45 g because the instrument only
measures to the hundredths place.
Page 2 of 110
,500 Flashcards Praxis Biology 5236 Exam
What is the primary purpose of a control group in an
experiment?
A control group provides a standard for comparison and
helps determine whether the independent variable caused
observed changes.
Distinguish between qualitative and quantitative data.
Qualitative data are descriptive observations such as color
or texture, while quantitative data involve numerical
measurements such as mass, temperature, or time.
A student observes that enzyme activity doubles when
temperature increases from 20°C to 30°C. The student
concludes enzymes always work better at higher
temperatures. Why is this flawed?
The conclusion is flawed because extrapolation beyond
tested conditions may be inaccurate. Extremely high
temperatures can denature enzymes and reduce activity.
A model used to represent DNA structure may be revised
when new __________ becomes available.
Evidence or data.
Page 3 of 110
, 500 Flashcards Praxis Biology 5236 Exam
Why are models important in biology?
Models simplify complex systems, help explain natural
phenomena, allow predictions, and can be modified when
new evidence emerges.
A researcher measures plant growth in centimeters every
day for 30 days. What type of data is being collected?
Quantitative data because numerical measurements are
recorded.
Which scientific skill is demonstrated when organisms are
grouped according to shared traits?
Categorizing.
Explain dimensional analysis and its importance in biology
labs.
Dimensional analysis is the use of conversion factors to
change units while maintaining equivalent quantities. It
ensures accurate calculations and measurements in
experiments.
Page 4 of 110
Define a scientific hypothesis and explain how it differs from
a scientific theory.
A scientific hypothesis is a testable and falsifiable
explanation for an observation or phenomenon. A scientific
theory is a broad, well-supported explanation backed by
repeated experimentation and extensive evidence. A
hypothesis may become supported by evidence, but
theories do not "graduate" into laws.
A student claims, "Plants grow faster because music makes
them happy." Identify the problem with this statement
scientifically.
The statement is not scientifically rigorous because "happy"
is subjective and not measurable. Scientific explanations
require measurable variables such as growth rate, light
exposure, or hormone activity.
In an experiment, the variable intentionally changed by the
researcher is called the __________ variable.
Independent variable.
Page 1 of 110
,500 Flashcards Praxis Biology 5236 Exam
In a bacterial growth experiment, nutrient concentration is
changed while temperature is kept constant. Identify the
dependent variable.
The dependent variable is bacterial growth because it is the
measured response affected by nutrient concentration.
Explain why scientific knowledge changes over time.
Scientific knowledge changes because new observations,
technologies, and experimental evidence may refine or
replace previous explanations. Science is self-correcting.
Scientific laws explain why natural phenomena occur. Give
reasoning.
False. Scientific laws describe patterns or relationships
observed in nature, while scientific theories explain why
those phenomena occur.
A biology student records mass as 12.450 g on a balance
that only measures to 0.01 g. What is the error?
The student used too many significant figures. The value
should be reported as 12.45 g because the instrument only
measures to the hundredths place.
Page 2 of 110
,500 Flashcards Praxis Biology 5236 Exam
What is the primary purpose of a control group in an
experiment?
A control group provides a standard for comparison and
helps determine whether the independent variable caused
observed changes.
Distinguish between qualitative and quantitative data.
Qualitative data are descriptive observations such as color
or texture, while quantitative data involve numerical
measurements such as mass, temperature, or time.
A student observes that enzyme activity doubles when
temperature increases from 20°C to 30°C. The student
concludes enzymes always work better at higher
temperatures. Why is this flawed?
The conclusion is flawed because extrapolation beyond
tested conditions may be inaccurate. Extremely high
temperatures can denature enzymes and reduce activity.
A model used to represent DNA structure may be revised
when new __________ becomes available.
Evidence or data.
Page 3 of 110
, 500 Flashcards Praxis Biology 5236 Exam
Why are models important in biology?
Models simplify complex systems, help explain natural
phenomena, allow predictions, and can be modified when
new evidence emerges.
A researcher measures plant growth in centimeters every
day for 30 days. What type of data is being collected?
Quantitative data because numerical measurements are
recorded.
Which scientific skill is demonstrated when organisms are
grouped according to shared traits?
Categorizing.
Explain dimensional analysis and its importance in biology
labs.
Dimensional analysis is the use of conversion factors to
change units while maintaining equivalent quantities. It
ensures accurate calculations and measurements in
experiments.
Page 4 of 110
