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WorksheetsBiology: Module 6 Test Review
Total questions: 77
Worksheet time: 39mins
What is the most abundant element found in living things?
Carbon
Nitrogen
Oxygen
Hydrogen
How many naturally occurring elements exist?
82
92
100
118
What type of bond forms when electrons are shared between atoms?
Hydrogen bond
Ionic bond
Covalent bond
Van der Waals bond
What makes isotopes of the same element different from each other?
Number of protons
Number of electrons
Number of neutrons
Atomic mass
What is the overall charge of a neutral atom?
Positive
Negative
Zero
Variable
Which particles are located in the nucleus of an atom?
Electrons and protons
Protons and neutrons
Neutrons and electrons
Ions and protons
What was the main impact of oxygen on life's development?
It reduced organism complexity
It made organisms smaller
It slowed down evolution
It drove the development of complexity
What determines an element's identity?
Number of neutrons
Number of protons
Number of electrons
Atomic mass
Which type of bond involves the transfer of electrons between atoms?
Covalent bond
Ionic bond
Hydrogen bond
Double bond
What is a compound?
A single type of atom
A mixture of elements
A group of similar atoms
Two or more elements chemically combined
How many protons does an atom with 13 electrons have?
12
13
14
26
What makes carbon-14 radioactive?
Its number of electrons
Its nucleus decays and breaks apart
Its atomic number
Its number of protons
Which statement about molecules is correct?
All molecules are compounds
Molecules only contain ionic bonds
All compounds are molecules
Molecules can contain one or more types of atoms
What is the main difference between ionic and covalent bonds?
Ionic bonds share electrons, covalent bonds transfer electrons
Ionic bonds transfer electrons, covalent bonds share electrons
Ionic bonds only occur in metals
Covalent bonds only occur in non-metals
What information can be found in an element's block on the periodic table?
Only atomic number
Only atomic mass
Only chemical properties
Atomic number, mass, and symbol
What characteristic do elements in the same group share?
Similar chemical properties
Same number of neutrons
Same atomic mass
Same number of protons
Which particles carry a negative charge in an atom?
Protons
Neutrons
Electrons
Nucleus
What happens when an atom gains or loses electrons?
It becomes an isotope
It becomes an ion
It becomes a compound
It becomes a molecule
What is the minimum amount of energy needed for reactants to form products in a chemical reaction?
Substrate energy
Activation energy
Catalyst energy
Product energy
Where does a substrate bind on an enzyme?
Reaction site
Binding pocket
Active site
Enzyme core
In a chemical reaction, what happens to matter?
It can be created but not destroyed
It can be destroyed but not created
It can neither be created nor destroyed
It can both be created and destroyed
Which of the following is NOT a factor that affects enzyme activity?
pH
Temperature
Oxygen levels
Other substances
What is the primary function of a catalyst in a chemical reaction?
Increases the activation energy
Creates new products
Lowers the activation energy
Changes the reactants
In the equation 2H₂O₂ → 2H₂O + O₂, which are the products?
H₂O₂ only
H₂O and O₂
H₂O₂ and H₂O
O₂ only
Why must chemical equations be balanced?
To make calculations easier
To follow laboratory safety rules
To make reactions go faster
Because matter cannot be created or destroyed
What type of molecules are enzymes?
Carbohydrates
Lipids
Proteins
Nucleic acids
How many different reactions can most enzymes catalyze?
One specific reaction
Multiple similar reactions
Any type of reaction
Two different reactions
What happens in an exothermic reaction?
No energy change occurs
Energy is absorbed from the surroundings
Energy transforms into matter
Energy is released to the surroundings
In the chemical equation N₂ + 3H₂ → 2NH₃, what are the reactants?
NH₃ only
N₂ and NH₃
N₂ and H₂
H₂ only
Why can't bacteria that live in extremely hot environments (100°C) survive in the human body?
They need more oxygen
Their enzymes won't function at body temperature
The pH is too high
They can't find nutrients
What is a substrate?
A type of enzyme
A product of a reaction
A catalyst
A reactant that binds to an enzyme
Which statement about enzymes is FALSE?
They are specific to one reaction
They require an active site
They lower activation energy
They permanently change during reactions
What must be equal on both sides of a balanced chemical equation?
Number of molecules only
Number of atoms of each element
Temperature of the reaction
Number of reactants and products
In a chemical reaction, what are the starting substances called?
Products
Catalysts
Reactants
Enzymes
Why do living organisms need enzymes?
To create new matter
To destroy waste products
To speed up chemical reactions
To slow down metabolism
What happens to activation energy when an enzyme is present?
It increases slightly
It remains the same
It decreases
It doubles
Which of the following best describes a chemical reaction?
A physical change in matter
A reorganization of atoms into different substances
A change in temperature only
A change in color only
How do enzymes maintain specificity in biological reactions?
By working at any temperature
By having a specific active site shape
By binding to all substances
By changing their shape randomly
What is the primary characteristic of a polar molecule?
It has no electrical charge
It has oppositely charged regions
It has only positive charges
It has equal distribution of charges
Which type of bond is formed when a charged region of a polar molecule interacts with an oppositely charged region of another polar molecule?
Covalent bond
Ionic bond
Hydrogen bond
Peptide bond
What is the main reason water is an effective solvent?
Its high boiling point
Its density
Its polarity
Its colorless nature
Which of the following is a characteristic of a homogeneous mixture?
Particles settle over time
Uniform composition throughout
Components remain distinct
Visible separation of components
In a solution of salt water, what is the solvent?
Salt
Water
Both salt and water
Neither salt nor water
What determines the strength of an acid or base?
The volume of the solution
The concentration of hydrogen or hydroxide ions
The color of the solution
The temperature of the solution
Which statement about van der Waals forces is correct?
They are stronger than covalent bonds
They are weak electrostatic attractions
They only occur in non-polar molecules
They are permanent bonds
What type of mixture is a suspension?
Homogeneous
Heterogeneous
Pure substance
Element
Which atoms can form hydrogen bonds with hydrogen?
Carbon, hydrogen, and helium
Fluorine, oxygen, and nitrogen
Sodium, potassium, and lithium
Iron, copper, and zinc
What happens when an acid dissolves in water?
It releases OH- ions
It releases H+ ions
It releases neutral molecules
It releases electrons
What is the pH value of a neutral solution?
0
14
7
3.5
Which property of water is due to hydrogen bonding?
Its metallic nature
Its cohesive properties
Its radioactivity
Its flammability
What is the primary function of a buffer?
To increase acidity
To maintain stable pH
To increase temperature
To change color
Which of the following is a heterogeneous mixture?
Sugar water
Salt water
Oil and vinegar
Tap water
What happens to the pH when H+ ion concentration increases?
pH increases
pH decreases
pH stays the same
pH becomes neutral
Which characteristic is NOT associated with bases?
pH greater than 7
Bitter taste
Releases H+ ions
Slippery feel
What type of forces determine physical characteristics like boiling and melting points?
Nuclear forces
Gravitational forces
Intermolecular forces
Magnetic forces
In a solution, the substance being dissolved is called the:
Solvent
Solution
Mixture
Solute
What type of mixture has particles that do not settle out over time?
Solution
Suspension
Colloid
Pure substance
Which statement about water molecules is correct?
They have no charge
They have two positive ends and one negative end
They have equal charge distribution
They have two negative ends and one positive end
Which branch of chemistry studies compounds containing carbon?
Physical chemistry
Organic chemistry
Inorganic chemistry
Nuclear chemistry
What is the primary function of lipids in living organisms?
Storing genetic information
Catalyzing chemical reactions
Energy storage
Transporting substances
How many different amino acids are commonly found in proteins?
10
15
20
25
What is the term for a molecule made from repeating units of identical or nearly identical compounds?
Monomer
Polymer
Macromolecule
Nucleotide
Which of the following is the general formula for carbohydrates?
(CH2O)n
(CHO)n
(CO2H)n
(CH3O)n
What type of bonds join amino acids together in proteins?
Hydrogen bonds
Ionic bonds
Peptide bonds
Covalent bonds
Which level of protein structure represents the basic amino acid chain?
Secondary structure
Tertiary structure
Primary structure
Quaternary structure
What are the building blocks of nucleic acids called?
Amino acids
Nucleotides
Monosaccharides
Fatty acids
When two monosaccharides join together, what is the resulting molecule called?
Polysaccharide
Disaccharide
Oligosaccharide
Complex sugar
What elements are always present in amino acids?
Carbon, hydrogen, and oxygen only
Carbon, nitrogen, and sulfur only
Carbon, hydrogen, oxygen, and nitrogen
Carbon, hydrogen, oxygen, nitrogen, and phosphorus
Which type of biological molecule can form a honeycomb structure in beehives?
Proteins
Carbohydrates
Nucleic acids
Lipids
What is the main function of nucleic acids?
Energy storage
Structural support
Genetic information storage
Enzyme catalysis
Which macromolecule is responsible for speeding up chemical reactions in cells?
Proteins
Carbohydrates
Lipids
Nucleic acids
What is the term for large molecules formed by joining smaller organic molecules together?
Polymers
Monomers
Macromolecules
Nucleotides
Which of these is NOT a function of proteins?
Structural support
Energy storage
Transport of substances
Cell signaling
What types of nucleic acids are found in living organisms?
RNA and DNA
DNA and ATP
RNA and ADP
ATP and AMP
Which component gives amino acids their variable characteristics?
Amino group
Side chain
Hydroxyl group
Carbon backbone
What is the primary role of carbohydrates in organisms?
Genetic information storage
Energy source
Membrane formation
Enzyme activity
Which structure represents the most complex level of protein organization?
Primary structure
Secondary structure
Tertiary structure
Quaternary structure
