BIO EXAM #1

define matter

Anything that occupies space and has mass

define solvent

In a solution, the chemical that does the dissolving

define acid

A solution with a pH less than 7

Define hydrophilic

Readily interacts with water

Define Hydrophobic

An example of this type of molecules is hydrocarbons

Define nucleus

Central region of an atom

Define Valence Shell

The outermost electron level in an atom

Define element

any substance that cannot be broken down by a chemical reaction into a simpler substance

Define compound

Any substance made up of atoms of 2 or more different elements that are chemically bonded

Define Anion

a negatively charged atom or group of atoms

Define Solute

In a solution, the chemical that is dissolved

Define Isomers

Molecules with the same chemical formula, but different structures

Define Cation

A positively charged atom or group of atoms

Define Electron

A negatively charged subatomic particle

Define Enantiomer

Molecules that are mirror images of each other

Define Base

A solution with a pH greater than 7

Define Reactants

In a chemical equation, the chemicals on the left side of the equation

Define Mixture

Any substance of two or more different materials that share the same space but are not chemically bonded together

Define Mass

Mass number # of protons and neutrons in an atom

Define Products

Products In a chemical equation, the chemicals on the right side of the equation

Define Atomic number

the number of protons in an atom

Define Isotopes

Atoms of the same element with different mass numbers

Define Atomic weight

Average atomic mass of all the isotopes for an element

Define. Buffer

A chemical that prevents drastic changes in pH

Define Proton

Subatomic particle with a positive charge

What are the six steps of the scientific method in order?

Observation → Question → Hypothesis → Prediction → Testing → Data Analysis/Conclusion.

A doctor notices that patients taking a certain medication recover faster. What step of the scientific method is this?

Observation.

A scientist asks, "Does this medication decrease recovery time?" What step is this?

Question.

A researcher proposes, "Patients who take this medication will recover faster than patients who do not." What step is this?

Hypothesis.

A scientist predicts that patients receiving a new drug will have lower blood pressure than patients receiving a placebo. What step is this?

Prediction.

A researcher gives patients the drug and placebo and measures their blood pressure. What step is this?

Testing.

After collecting blood pressure measurements, a researcher determines whether the results support the hypothesis. What step is this?

Data analysis/conclusion.

What two characteristics must a valid scientific hypothesis have?

It must be testable and falsifiable.

A statement says, "Taking medication X will reduce blood pressure." Why is this a testable hypothesis?

You can conduct an experiment and measure blood pressure in people who take medication X.

A statement says, "A supernatural force that cannot be detected causes people to recover." Why would this not be a valid scientific hypothesis?

It cannot be tested or potentially shown to be false.

A researcher wants to test whether a new drug affects blood pressure. What would an appropriate null hypothesis be?

The drug has no effect on blood pressure.

A researcher predicts that a new drug will lower blood pressure. What would the alternative hypothesis be?

The drug will lower blood pressure.

A study compares the rate of lung cancer in smokers and nonsmokers without assigning people to smoke or not smoke. Is this comparative or controlled?

Comparative.

Why is the lung cancer smoker vs. nonsmoker study considered a comparative experiment?

It compares differences between groups but does not manipulate whether people smoke.

Researchers give one group Drug A and another group a placebo to determine whether Drug A lowers blood pressure. Is this comparative or controlled?

Controlled.

What makes a controlled experiment different from a simple comparison?

The researcher deliberately manipulates the variable predicted to cause the difference.

Researchers change the amount of medication given to patients. What is the independent variable?

The amount/dose of medication.

Researchers measure patients' blood pressure after giving different doses of medication. What is the dependent variable?

Blood pressure.

A researcher changes the amount of exercise participants perform and measures their weight afterward. What is the independent variable?

Amount of exercise.

A researcher changes the amount of exercise participants perform and measures their weight afterward. What is the dependent variable?

Weight.

In a drug trial, one group receives the new medication and another receives a pill containing no medication. What is the group receiving the new medication?

Experimental group.

In a drug trial, one group receives the new medication and another receives a pill containing no medication. What is the pill-without-medication group?

Negative control group.

Why is a placebo group useful in a clinical trial?

It provides a comparison group so researchers can determine whether the active treatment caused the effect.

A group receives a treatment that is already known to produce the expected effect. What type of control is this?

Positive control.

Why would researchers use a positive control?

To confirm that the experimental system can detect an expected effect.

Why are patients randomly assigned to treatment groups?

To help make the groups similar in characteristics and reduce bias/confounding variables.

Why is randomization important when comparing two treatment groups?

It makes it less likely that preexisting differences between groups explain the results.

In a double-blind clinical trial, who knows which participants receive the experimental treatment?

Neither the participants nor the researchers interacting with them know.

Why are clinical trials often double-blind?

To reduce bias from both participants' expectations and researchers' expectations.

A patient reports feeling better because they believe they received the new drug, even though they received a placebo. What problem is the trial designed to reduce?

Bias/placebo effects.

Researchers test a medication in a laboratory dish before giving it to humans. Is this in vitro or in vivo?

In vitro.

Researchers test a medication on a living animal before beginning human trials. Is this in vitro or in vivo?

In vivo.

What are the two major goals of preclinical drug studies?

To determine whether the treatment appears safe and effective enough to move toward human testing.

What two major things are researchers looking for during clinical studies of a new drug?

Safety and efficacy.

A study produces nearly the same measurement every time, but the measurements are far from the true value. Is it accurate, precise, both, or neither?

Precise but not accurate.

A thermometer consistently reads 2°F higher than the actual temperature. Is it accurate, precise, or both?

Precise but not accurate.

A thermometer gives readings of 98.6°F, 98.6°F, and 98.7°F when the true temperature is 98.6°F. Is it accurate and/or precise?

Both accurate and precise.

A scale gives measurements of 120, 120, and 120 pounds when the person's true weight is 125 pounds. Is it accurate, precise, both, or neither?

Precise but not accurate.

A measurement is very close to the accepted or true value. What quality does this demonstrate?

Accuracy.

Repeated measurements are very close to each other but may not be close to the true value. What quality does this demonstrate?

Precision.

A study finds that people who exercise more tend to have lower blood pressure. Does this alone prove exercise causes lower blood pressure?

No. It demonstrates correlation, but correlation alone does not prove causation.

Researchers find that ice cream sales and sunburns both increase during summer. Does ice cream cause sunburn?

No. The variables are correlated because another factor, such as hot/sunny weather, may influence both.

If researchers deliberately assign participants to exercise and then measure their blood pressure, can the study provide stronger evidence for causation?

Yes, because the researchers manipulate the independent variable and measure the resulting response.

A researcher discovers that two variables change together. What can the researcher conclude immediately?

They are correlated or associated, but causation has not necessarily been established.

A scientific explanation is supported by a large body of evidence, is broad in scope, and generates new hypotheses. Is it a theory or law?

Theory.

A scientific statement describes a consistent pattern of what happens in nature. Is it more likely a theory or law?

Law.

Does a scientific theory mean that scientists are simply guessing?

No. A scientific theory is a well-supported explanation based on substantial evidence.

Which is broader: a scientific theory or a scientific law?

A scientific law is generally more general in describing what happens, while a theory provides a broad explanation and generates hypotheses.

Which can generate new hypotheses: a scientific theory or a scientific law?

A scientific theory.

The germ theory of disease explains how microorganisms can cause disease. Is this an example of a scientific theory or law?

Scientific theory.

A scientist observes that several patients improve after taking a drug and concludes that the drug is effective in general. What type of reasoning is this?

Inductive reasoning.

A scientist knows that a certain medication lowers blood pressure and predicts that a specific patient taking the medication will have lower blood pressure. What type of reasoning is this?

Deductive reasoning.

Which direction does inductive reasoning move: specific observations to a general principle, or general principle to a specific prediction?

Specific observations → general principle.

Which direction does deductive reasoning move: specific observations to a general principle, or general principle to a specific prediction?

General principle → specific prediction.

A scientist notices several examples and uses them to develop a general conclusion. What type of reasoning is being used?

Inductive reasoning.

A scientist starts with a general principle and applies it to a specific case. What type of reasoning is being used?

Deductive reasoning.

A scientist asks questions rather than automatically accepting a claim. Which critical-thinking attribute is being demonstrated?

Questioning.

A scientist looks for evidence before accepting a medical claim. Which critical-thinking attributes are being demonstrated?

Reasoning and learning/researching.

A scientist is willing to change their conclusion when new evidence appears. Which critical-thinking attribute is being demonstrated?

Being open to new ideas.

A scientist investigates a claim because they want to know whether it is true. Which critical-thinking attribute is being demonstrated?

Curiosity.

A scientist asks, "What evidence supports this assumption?" Which critical-thinking skill is being demonstrated?

Challenging assumptions.

A researcher considers whether personal expectations could influence the interpretation of results. What critical-thinking skill is being used?

Confronting potential biases.

Why is critical thinking important when reading medical information?

It helps you evaluate evidence, recognize bias, challenge assumptions, and distinguish reliable scientific information from unsupported claims.

Why is understanding science important in medicine?

It helps healthcare professionals read and evaluate information, communicate effectively, answer patient questions, and understand clinical research.

All matter is made of what?

Atoms.

What are the three subatomic particles that make up atoms?

Protons, neutrons, and electrons.

Which two subatomic particles are found in the nucleus?

Protons and neutrons.

Which subatomic particle orbits the nucleus?

Electron.

Which subatomic particle determines the identity of an element?

Proton.

An atom has 6 protons. What element must it be?

Carbon.

Why must every carbon atom have 6 protons?

The number of protons, or atomic number, identifies the element.

A carbon atom has 6 protons and 6 neutrons. What is its mass number?

12.

A carbon atom has 6 protons and 7 neutrons. What is its mass number?

13.

A carbon atom has 6 protons and 8 neutrons. What is its mass number?

14.

Carbon-12, carbon-13, and carbon-14 are all carbon. What makes them different?

They have different numbers of neutrons.