NAS2 CHALLENGE EXAM STUDY GUIDE 2026
FULL QUESTIONS AND SOLUTIONS VERIFIED
● independent variable Answer: a variable that the researcher controls
and is not affected by other variables
ex: amount of water a plant receives
● What are the steps of the scientific method? Answer: 1. question
2. Hypothesis
3. experiment
4. observation
5. analyze
6. conclusion
● dependent variable Answer: a variable that depends on other factors or
variables
ex: how much the plant grows
● control group Answer: group that does not receive any treatment and
is used to compare or measure the other subjects
,● experimental group Answer: group that receives treatment in an
experiment
● what are the six levels of organization Answer: chemical, cellular,
tissue, organ, organ system, organism
● identify the requirements of life Answer: response to stimuli,
reproduction, metabolism, cellular organization, regulation, growth and
development, homeostasis
● identify survival needs Answer: oxygen, nutrients, water, body
temperature, atmospheric pressure
● define homeostasis Answer: body maintains a stable internal
environment while adjusting to external conditions
● Receptor Answer: a sensor that monitors the environment and
responds to changes (called stimuli) by sending the information to the
control center
● control center Answer: determines the set point (level or range a
variable is to be maintained at), analyzes the information it receives, and
determines the appropriate response.
, ● effector Answer: provides the means for the control center's response
to the stimulus
● negative feedback mechanisms Answer: a feedback mechanism that
slows or stops a process. Reduces the effect of the stimulus which
decreases productivity
ex: the control of blood sugar
● positive feedback mechanisms Answer: a feedback mechanism that
results in the enhancement of the original stimulus so the activity is
accelerated
ex: childbirth (if childbirth takes too long the life of the mother and baby
are at risk)
● protons Answer: positive, in the nucleus
● electron Answer: negatively charged particle in the outer shell
● neutron Answer: neutral charge, in the nucleus
● number of protons is the same as? Answer: the number of electrons
● what is the atomic number equal to Answer: number of protons
(atomic number is top left above atomic symbol)
FULL QUESTIONS AND SOLUTIONS VERIFIED
● independent variable Answer: a variable that the researcher controls
and is not affected by other variables
ex: amount of water a plant receives
● What are the steps of the scientific method? Answer: 1. question
2. Hypothesis
3. experiment
4. observation
5. analyze
6. conclusion
● dependent variable Answer: a variable that depends on other factors or
variables
ex: how much the plant grows
● control group Answer: group that does not receive any treatment and
is used to compare or measure the other subjects
,● experimental group Answer: group that receives treatment in an
experiment
● what are the six levels of organization Answer: chemical, cellular,
tissue, organ, organ system, organism
● identify the requirements of life Answer: response to stimuli,
reproduction, metabolism, cellular organization, regulation, growth and
development, homeostasis
● identify survival needs Answer: oxygen, nutrients, water, body
temperature, atmospheric pressure
● define homeostasis Answer: body maintains a stable internal
environment while adjusting to external conditions
● Receptor Answer: a sensor that monitors the environment and
responds to changes (called stimuli) by sending the information to the
control center
● control center Answer: determines the set point (level or range a
variable is to be maintained at), analyzes the information it receives, and
determines the appropriate response.
, ● effector Answer: provides the means for the control center's response
to the stimulus
● negative feedback mechanisms Answer: a feedback mechanism that
slows or stops a process. Reduces the effect of the stimulus which
decreases productivity
ex: the control of blood sugar
● positive feedback mechanisms Answer: a feedback mechanism that
results in the enhancement of the original stimulus so the activity is
accelerated
ex: childbirth (if childbirth takes too long the life of the mother and baby
are at risk)
● protons Answer: positive, in the nucleus
● electron Answer: negatively charged particle in the outer shell
● neutron Answer: neutral charge, in the nucleus
● number of protons is the same as? Answer: the number of electrons
● what is the atomic number equal to Answer: number of protons
(atomic number is top left above atomic symbol)
