Characteristics of Life
What characteristic of life is shown when a plant becomes taller over several weeks?
Growth
What is usually the first step in scientific investigation?
Observations
In a controlled experiment, how many variables should a scientist deliberately change at a time?
ONE
What is information gathered during an experiment called?
data
A living part of an ecosystem, such as a bird, tree, or bacterium, is called this.
Biotic
What characteristic of life is shown when birds fly south for the winter?
Respond to the environment
What is a testable explanation for an observation called?
Hypothesis
What is the variable deliberately changed by the scientist?
The independent variable
“The flower is bright yellow” is what type of observation?
qualitative
This characteristic of life takes place over many generations and can produce adaptations in populations.
Evolution
What process allows an organism to keep its internal conditions fairly constant?
Homeostasis
What must a hypothesis be able to do in order to have scientific value?
Testable!
What is the variable that responds to a change in an experiment?
The dependent variable
“The plant has five tomatoes” is what type of observation?
Arrange these levels of biological organization from smallest to largest: organism, tissue, organ system, cell, organ.
cell → tissue → organ → organ system → organism
All living things are made of one or more of what basic units?
Cells
A scientist suggests that adding water will increase the growth of bread mold. What part of scientific investigation is this statement?
A hypothesis or claim
A scientist changes the amount of water given to several plants and measures their growth. What is the independent variable?
The amount of water
Which type of observation uses numbers or measurements?
quantitative
"The flower petals are bright red and wrinkled" is this type of observation.
Qualitative
Name two characteristics shared by all living things.
Possible answers include being made of cells, growing, reproducing, responding to the environment, maintaining homeostasis, using energy, and having genetic information.
Why do scientists publish the details of important experiments?
So other scientists can repeat or reproduce the experiments and compare the results.
In an experiment, a scientist changes the amount of fertilizer and measures plant height. Identify the independent variable and the dependent variable.
The independent variable is the amount of fertilizer. The dependent variable is the plant height.
A student records that a plant is 18 centimeters tall and has three new leaves. What makes these observations quantitative?
There is a measurement (number)
Name and describe the three main parts of a Claim-Evidence-Reasoning response.
Claim: A statement that answers the question or makes a conclusion.
Evidence: Specific observations or data that support the claim.
Reasoning: An explanation of how the evidence supports the claim using scientific ideas.