BioALV

No. A controlled study only changes one variable at a time.

A research team designs an experiment to increase the speed of athletes. The athletes' diet and sleep routines are altered for two weeks. Is this an example of a controlled study?

hypothesis

A(n) ______ is a proposed explanation for a set of observations. It leads to predictions that can be tested by additional observations or by experiments.

controlled experiment

A(n) ________ involves running a test multiple times while changing one variable, leaving the others the same.

Scientists use the word theory to mean a hypothesis that has been supported by many experiments; non-scientists use the word theory to mean a hypothesis that remains to be well tested.

Evaluate the following statements; which statement is accurate?

It does not pass on genes for traits to its offspring, It does not consist of complex, well-ordered structures, and It does not have cells.

Fire can move, grow, reproduce, use energy, consume oxygen, and interact with its environment. Why is it not alive?

Life is defined through a set of shared characteristics that all living things display.

How is life defined?

develop a hypothesis

If you were to evaluate these claims using the scientific method, what would be the first step?

double-blind

In a _______ experiment, neither the participants nor the researchers know who receives the treatment and who does not.

single-blind

In a ________ experiment, the researchers--but not the participants--know who receives the treatment and who does not, to eliminate subjective bias.

Placebo effect

Many medical studies show that patients who receive a treatment feel better even if the treatment was an ineffective sugar pill. What is this phenomenon called?

scientific method

Scientists use a general process known as the ________ to ask and answer questions about nature.

Skin consists of multiple tissue types that cooperate to perform a specific task.

Skin is sometimes referred to as the largest organ of the body. Why is skin considered to be an organ and not a tissue or some other structure?

independent variable

The one variable that is manipulated by a scientist as a potential cause in an experiment is the

population

The statement, "There are 628 gray squirrels living on campus," describes the ________ of gray squirrels on campus.

controlled

The type of test that changes only one variable at a time in order to isolate the results is known as a _____ experiment

The fertilizer amount (independent), The tomato yield at the end of the growing season (dependent)

Use the following study to answer the following question(s): A researcher applies varying amounts of fertilizer (0, 2, 4, 8, 10 units) to 50 potted tomato plants. All other variables that may affect the outcome (watering, temperature, sunlight, plant size, etc.) are kept the same from pot to pot. At the end of the growing season, the tomatoes grown on each plant are weighed to determine which fertilizer level produced the largest tomato yield. Which are the dependent and independent variable?

This study was evaluated by qualified and impartial experts before being published.

What does it mean when we say, "This scientific study was published in a peer-reviewed journal"?

The theory of evolution by natural selection

What is the core theme that unifies all of biology?

A primary source is the original material published by the scientists, whereas a secondary source is a description of the original material.

What is the difference between a primary and a secondary source?

beliefs

Which of the following features would be useful in identifying pseudoscience?

control group

establishes a base line for an experiment.

positive control

is a group in which a known response is expected.

negative control

is a group in which no response is expected.

theory

is broader in scope than a hypothesis, is supported by a large body of evidence, and generates many new hypotheses.

Dependent Variable

is the factor a scientist observes to see the effect of the change made.

molecule, cell, tissue, organ, organism, population, community, ecosystem, biosphere

levels of biological organization from smallest to largest