biolgy chapter 2
in a well designed experiment, ___ independent variables change
1
which of the following is an accurate description of a testable question?
a question that can be answered using an experiment
which of the following is an accurate description of a testable question?
a question that can be answered using test or experiments
which of the following problems could be solved following the steps of the scientific method?
all of the above
ming is having trouble sleeping and decides to participate in a study to determine whether a certain medication helps people sleep. there are 30 volunteers each of whom is assigned to 1 of 2 groups. volunteers in group 1 are given the medication and volunteers in group 2 are given a placebo (pill w no meds). which step is important in order to ensure scientifically valid results?
assigning the subjects to group at random
which of the following should be included when making a general question table ?
both the cause and effect of the change that is being tested
which of the following should be included when making a general question testable?
both the cause and effect of the change that is being tested
several students in a biology lab tested mealworms preference for damp or dry conditions. the students placed 50 mealworms one by one in the middle of a layer of paper towels with a damp area and a dry area. the mealworms were allowed to move freely over the paper towel for 10 min. after 10 minuites the students noted the location of each mealworm.... which of the following would provide the most accurate results for an experiment?
compare a large sample size from multiple trials
the part of the experiment that is established to dtermine what happens under normal conitions
control
in an experiment, one group that is tested does not experience any change in variables that are being studied. what is that group called
control group
which of the following is an example of a dependent variable?
counting the number of seeds that sprout in 10 different containers that recieved different types of fertilizer
the part of the experiment that is measured to determine the effects of the experiment
dependent variable
which of the following is an example of a testable question?
does increasing the tempature of water cause salt to dissolve at a faster rate?
which of the following is an example of a testable question?
does increasing the tempature of water cause salt to dissolve faster?
a testable question states a general observation of nature
false
all questions in science are testable
false
all questions in science are testable.
false
does adding fertilizer have an affect on the growth rate of a plant? what is the dependent variable in this question?
growth rate
a scientist wanted to learn more about population growth in baceteria. the scientist wanted to know "does storing bacterial cultures at a lower tempature affect the growth rate of the bacterial populations?" in this scenario what is the dependent variable?"
growth rate of the population
which of the following questions would basic research be used to answer?
how do dragon flies reproduce?
the part of the experiment that the scientist changes in order to test the effects
independent variable
what is a hypothesis?
it is a statemnt of what the researcher thinks will happen in an experiment
the independent variable is the variable ___
manipulated by the scientist running the experiment
several students in a biology lab tested mealworms preference for damp or dry conditions. the students placed 50 mealworms one by one in the middle of a layer of paper towels with a damp area and a dry area. the mealworms were allowed to move freely over the paper towel for 10 min. after 10 minuites the students noted the location of each mealworm.... which conclusion best supports the data collected in both experiments?
mealworms are more strongly influenced by food than damp or dry coditions
why should you preform multiple trials of experiments ?
multiple trials provide more results in order to eliminate inconsistencies due to human error
if a researcher makes an experimental observation that is contrary to well established scientific understanding, what should the next step be?
re-evaluating the procedure and replicating the experiment
the part of the experiment that is analyzed in order to form a conclusion.
results
which of the following describes a controlled experiment
set up 10 plants with the same seeds, sunlight and water and vary the types of fertilizer
what is the first step of the scientific method?
state the problem
which experimental design would provide scientist with the best data for investing which type of feed yields the greatest gain in lean muscle mass in cattle?
test 5 similar groups of cows with 5 different feed mixtures and measure their weight gain at the end of a 6 week trial
applied science involves research____
that is necessitated by the problems resulting from some current issue
does adding fertilizer have an affect on the growth rate of a plant? in this question, what is the independent variable?
the fertilizer
which should be included in a testable question?
the indepentent and dependent variables
a scientist wanted to learn more about population growth in baceteria. the scientist wanted to know "does storing bacterial cultures at a lower tempature affect the growth rate of the bacterial populations?" in this scenario what is the independent variable?"
the tempature
variables in an experiment are...
things that can affect the outcome
what is the purpose of performing a controlled experiment?
to provide consistent results that can be repeated
it is important to run an experiment many, many times to get valid results
true
dr. hansen performs an experiment testing the effectivness of different cough syrups. identify the indepentent variable in the experiment
type of cough syrup
which of the following is an example of an independent variable ?
using different brands of fertilizers on 10 different containers of plants
___ are things that can affect the outcome of an experiment
variables
why do plants grow is a general question? which of the following demonstrates a testable question for plant growth??
will adding fertilizer to a plant increase the plant height after 3 weeks?
why do plants grow? is a general question. Which of the following demonstrates a testable question for plant growth?
will adding fertilizer to a plant increase the plant height after 3 weeks?