Biology Lecture Exam 1

Question 1

Define the scientific method?

Answer 1

The process that scientists use to investigate the natural world

Question 2

Define Data?

Answer 2

information that they can analyze, often using computers and statistical methods.

Question 3

Define Fact?

Answer 3

something KNOWN to be true

Question 4

What is a Hypothesis?

Answer 4

testable explanation for observations or phenomena

Question 5

What is an Independent Variable?

Answer 5

What you change in the experiment

Question 6

What is a Dependent Variable?

Answer 6

What you are measuring

Question 7

Predictions

Answer 7

What might be expected from experimental results.
Frame as specific if….then statements

Question 8

What is an Experimental Group?

Answer 8

In a scientific experiment, a group in which the experimental variable is manipulated.

Question 9

Control Group

Answer 9

In a scientific experiment, a group in which the experimental variable is kept constant.

Question 10

Placebo

Answer 10

Used as an control in science.

Question 11

Scientific Theory

Answer 11

an explanation supported by observations and experiments.

Question 12

What are electrons?

Answer 12

A particle with one unit of negative charge and negligible mass, located outside the atomic nucleus.

Question 13

What is a proton?

Answer 13

A particle present in the nuclei of all atoms that has one unit of positive charge and a mass of 1 atomic mass unit (amu).

Question 14

Define an Atom

Answer 14

as the smallest portion of an element that retains its chemical properties

Question 15

Define Neutrons

Answer 15

An electrically neutral particle with a mass of 1 atomic mass unit (amu) found in the atomic nucleus.

Question 16

Valence electrons

Answer 16

The electrons in the outer electron shell, known as the valence shell, of an atom

Question 17

Valence shell

Answer 17

The outermost shell of an atom containing the valence electrons

Question 18

Compound

Answer 18

A substance made of two or more chemically bonded elements.

Question 19

Molecule

Answer 19

The smallest particle of a covalently bonded element

Question 20

Covalent bond

Answer 20

Involved the sharing of valence electrons between two elements.

Question 21

Electronegativity

Answer 21

The Ability of an atom to attract shared electrons.

Question 22

Polar covalent bond

Answer 22

A covalent bond between atoms that differ in electronegativity

Question 23

Non polar covalent bond

Answer 23

When covalently bonded atoms have similar electronegativities the electrons are shared equally

Question 24

Cation

Answer 24

Positive charge
A particle with one or more units of positive charge

Question 25

Anion

Answer 25

Negative charge A particle with one or more units of negative charge

Question 26

Iconic bond

Answer 26

The chemical attraction between a cation and an anion.

Question 27

Hydrogen bond

Answer 27

A weak attractive force existing between a hydrogen atom with a partial positive charge and an electronegative atom (usually oxygen or nitrogen) with a partial negative charge.

Question 28

Cohesion

Answer 28

The property of sticking together.

Question 29

Adhesion

Answer 29

The property of sticking to some other substance.

Question 30

Capillary action

Answer 30

the tendency of water to move in narrow tubes, even against the force of gravity

Question 31

Surface tension

Answer 31

The attraction that the molecules at the surface of a liquid may have for one another. (I.e bug standing on water)

Question 32

Hydrophillic

Answer 32

Interact readily with water; having a greater affinity for water molecules than they have for each other. (“Water loving”, table salt , sugar) - occur between a group of polar molecules.

Question 33

Hydrophobic

Answer 33

Not readily interacting with water; having less affinity for water molecules than they have for each other (“water fearing, oil, gasoline) - Occur between groups of nonpolar molecules.

Question 34

Hydrophobic interaction

Answer 34

The tendency of hydrophobic substances to cluster together due to strong cohesive interactions among surrounding water molecules.

Question 35

Heat of vaporization

Answer 35

The amount of heat energy that must be supplied to change one gram of a substance from the liquid phase to the vapor phase.

Question 36

Specific heat

Answer 36

The amount of heat energy that must be supplied to raise the temperature of 1 g of a substance

Question 37

Acid

Answer 37

A substance that is a hydrogen ion proton donor; acids unite with bases to form salts.

Question 38

Base

Answer 38

Known as a proton accepter. a substance or combination of substances that resists changes in pH when an acid or base is added.

Question 39

pH

Answer 39

The negative logarithm of the hydrogen ion concentration of a solution (expressed as moles per liter). Neutral pH is 7, values less than 7 are acidic, and those greater than 7 are basic.

Question 40

Salt

Answer 40

a compound in which the hydrogen ion of an acid is replaced by some other cation

Question 41

amphipathic

Answer 41

A molecule that has both hydrophobic and hydrophilic

Question 42

Lipids

Answer 42

Any of a group of organic compounds that are insoluble in water but soluble in nonpolar solvents; lipids serve as energy storage and are important components of cell membranes.

Question 43

Nucleic acis

Answer 43

A class of biomolecules that are found in all living organisms

Question 44

Protein

Answer 44

Long chain molecules made of strings of amino acids

Question 45

Carbohydrates

Answer 45

Compound containing carbon, hydrogen, and oxygen, in the approximate ratio of C:2H:O (e.g., sugars, starch, and cellulose).