9th grade bio intro to bio quiz

What is an observation?

Something that is directly seen or measured and is based on evidence, not opinion.

Give an example of an observation.

The pavement is wet.

What is an inference?

A reasonable explanation or guess based on evidence from observations.

Give an example of an inference.

It rained earlier because the pavement is wet.

What is the difference between an observation and an inference?

An observation is directly obtained from evidence, while an inference is an explanation based on that evidence.

How many variables should be tested at one time?

One variable.

Why should only one variable be tested at a time?

So you can determine exactly what caused a change in the results.

Why is testing banana peels and double the water at the same time a problem?

You would not know whether the banana peels, extra water, or both caused the change.

What is an independent variable?

The variable that the experimenter changes.

How do you identify the independent variable?

Ask: 'What did the experiment change?'

What is an example of an independent variable?

The type of soil given to plants.

What is a dependent variable?

The variable that is measured or recorded.

How do you identify the dependent variable?

Ask: 'What data is being measured or recorded?'

What is an example of a dependent variable?

The growth of a plant.

What is a control group?

The group that does not receive the experimental change and provides a baseline for comparison.

How do you identify the control group?

Ask: 'What is the normal, unchanged test?'

Why is a control group important?

It provides baseline data that can be compared with the experimental results.

In a tomato experiment involving banana peels and extra water, what could be the control group?

Tomatoes grown without banana peels or extra water.

What is an atom?

The basic unit of matter and the smallest particle of an element that retains that element's chemical properties.

What are the three main subatomic particles?

Protons, neutrons, and electrons.

What charge does a proton have?

Positive (+1).

Where are protons located?

In the nucleus.

What charge does a neutron have?

Neutral (0).

Where are neutrons located?

In the nucleus.

What charge does an electron have?

Negative (-1).

Where are electrons located?

In the electron cloud surrounding the nucleus.

Which two subatomic particles are found in the nucleus?

Protons and neutrons.

Which subatomic particle is found in the electron cloud?

Electrons.

What is a molecule?

Two or more atoms chemically bonded together.

Can a molecule contain atoms of the same element?

Yes.

What is a compound?

A molecule made of two or more different elements chemically bonded together.

Give an example of a molecule that is not a compound.

O2, because it contains only oxygen atoms.

Give an example of a compound.

H2O or CO2.

What is the key rule about molecules and compounds?

All compounds are molecules, but not all molecules are compounds.

Why is O2 not a compound?

Because it contains only one element: oxygen.

Why is H2O a compound?

Because it contains two different elements: hydrogen and oxygen.

What are the six common elements you need to know?

Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur.

What is the symbol for Carbon?

C

What is the symbol for Hydrogen?

H

What is the symbol for Nitrogen?

N

What is the symbol for Oxygen?

O

What is the symbol for Phosphorus?

P

What is the symbol for Sulfur?

S

What does C H N O P S stand for?

Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur.

What is the independent variable in an experiment?

The variable that is deliberately changed by the experimenter.

What is the dependent variable in an experiment?

The variable that is measured or recorded.

What is the control group used for?

To provide baseline data for comparison.

What is the difference between the independent and dependent variables?

The independent variable is changed, while the dependent variable is measured.

What is the difference between a molecule and a compound?

A molecule contains two or more chemically bonded atoms; a compound is a molecule containing two or more different elements.