Final exam biology Exam with 100% Verified
Correct Answers
What is matter, and what states can it exist in? - ANSWER>>Matter is anything
that takes up space, by having a volume, and has mass. Matter can exist in a solid,
liquid or gaseous (vapor) state.
All matter is made up of certain basic substances called elements.
Explain the difference between essential and trace elements. -
ANSWER>>Essential elements are required for human life. Trace elements are
required only in small quantities.
Match each of the following molecular bonds with the correct description.
Ionic bonds - ANSWER>>Generated based on the attraction between oppositely
charged particles.
Match each of the following molecular bonds with the correct description.
Covalent bonds - ANSWER>>Occurs when electrons are shared by two atoms to
complete the valence shells of both.
Match each of the following molecular bonds with the correct description.
Hydrogen bonds - ANSWER>>Forms relatively weak bond that is easily broken.
True or False. If false, make the statement true:
,Anions are positively charged ions, and cations are negatively charged ions. -
ANSWER>>False. Cations are positively charged ions, and anions are negatively
charged ions.
Which of the following are not one fo the organic compounds that make up a
biomacromolecules?
1. Lipids
2. Proteins
3. Ribosomes
4. Carbohydrates - ANSWER>>Ribosomes.
What are carbohydrates? - ANSWER>>Carbohydrates, commonly referred to as
sugars, are the primary source of fuel for organisms and have the same three
elements in their main structure: carbon, hydrogen, and oxygen.
This is a biomacromolecule.
Why are lipids unique among the biomacromolecules? - ANSWER>>Lipids are
unique among the biomacromolecules because most of them are insoluble in
water. Additionally, lipids are not monomers but are assembled from smaller
molecules that are chemically linked together.
Why are lipids insoluble in water? - ANSWER>>Lipids are insoluble in water
because they are made mostly of non-polar hydrocarbon chains. As water is polar,
it will only dissolve other polar or ionically bonded substances. Lipids are non-
polar, and this is why they are insoluble in water but can dissolved with non-polar
solvents such as alcohol.
,Describe the structure of a phospholipid. - ANSWER>>Phospholipids contain two
main components: (1) a polar head group joined to (2) a non-polar tail group.
The head is composed of a charged phosphate group and (usually) a nitrogen-
containing group. The head is attracted to polar substances, such as water, and is
therefore hydrophilic (water loving). The tail group is a hydrocarbon-- a molecule
containing an H and C-- composed of non-polar fatty acid chains. The tail repels
water and is therefore hydrophobic (water fearing).
Name the functions of proteins as mentioned in the module. (7) -
ANSWER>>Proteins
-can act as enzymes and regulate metabolic functions,
-store amino acids,
-act as hormones,
-form antibodies for immunological defense,
-act as carriers for transport and also form membrane channels,
-form cell surface receptors to receive chemical messages,
-act as structural molecules for support and movement.
Describe how the shape of a protein is related to its function. (3) -
ANSWER>>Proteins can be assembled into a variety of shapes which allows them
to serve a variety of functions. Some functions of proteins are to make many
needed protective tissues such as skin, hair, and fingernails. Proteins also form
enzymes (catalysts that speed up chemical reactions) and are used to make
needed substances such as hemoglobin, which carries oxygen in red blood cells.
What are the roles of the two major types of nucleic acids? - ANSWER>>There are
two major types of nucleic acids: DNA (deoxyribonucleic acid) and RNA
(ribonucleic acid).
, DNA contains a vast amount of hereditary information and is responsible for the
inheritable characteristics of living organisms.
RNA is responsible for deciphering the hereditary information in DNA and using it
to synthesize proteins.
Describe the structure of DNA and RNA. - ANSWER>>DNA and RNA exist as chains
of nucleotides. The sugar of one nucleotide is linked to the phosphate of the next
nucleotide, while the nitrogenous base protrudes from each sugar in the string.
RNA is most commonly a single chain of nucleotides, whereas DNA is a double
chain held together by hydrogen bonds between protruding bases.
What are some of the main differences between prokaryotic and eukaryotic cells?
- ANSWER>>Prokaryotic cells (also-called prokaryotes) are considered simple cells
and have three defining characteristics: size, non-enclosed genetic material and
lack of organelles and other internal membrane bound structures.
Eukaryotic cells are more complex than prokaryotic cells. Most organisms are
composed of eukaryotic cells. Unlike prokaryotes, eukaryotes are 10-100 times
larger, possess a nuclear membrane (eukaryotic means "true nucleus") and
contain membrane-bound organelles.
What organelles of the cells are complexes of tiny manufacturing plants that
assemble proteins?
1. Endoplasmic reticulum
2. Lysosomes
3. Nucleus
Correct Answers
What is matter, and what states can it exist in? - ANSWER>>Matter is anything
that takes up space, by having a volume, and has mass. Matter can exist in a solid,
liquid or gaseous (vapor) state.
All matter is made up of certain basic substances called elements.
Explain the difference between essential and trace elements. -
ANSWER>>Essential elements are required for human life. Trace elements are
required only in small quantities.
Match each of the following molecular bonds with the correct description.
Ionic bonds - ANSWER>>Generated based on the attraction between oppositely
charged particles.
Match each of the following molecular bonds with the correct description.
Covalent bonds - ANSWER>>Occurs when electrons are shared by two atoms to
complete the valence shells of both.
Match each of the following molecular bonds with the correct description.
Hydrogen bonds - ANSWER>>Forms relatively weak bond that is easily broken.
True or False. If false, make the statement true:
,Anions are positively charged ions, and cations are negatively charged ions. -
ANSWER>>False. Cations are positively charged ions, and anions are negatively
charged ions.
Which of the following are not one fo the organic compounds that make up a
biomacromolecules?
1. Lipids
2. Proteins
3. Ribosomes
4. Carbohydrates - ANSWER>>Ribosomes.
What are carbohydrates? - ANSWER>>Carbohydrates, commonly referred to as
sugars, are the primary source of fuel for organisms and have the same three
elements in their main structure: carbon, hydrogen, and oxygen.
This is a biomacromolecule.
Why are lipids unique among the biomacromolecules? - ANSWER>>Lipids are
unique among the biomacromolecules because most of them are insoluble in
water. Additionally, lipids are not monomers but are assembled from smaller
molecules that are chemically linked together.
Why are lipids insoluble in water? - ANSWER>>Lipids are insoluble in water
because they are made mostly of non-polar hydrocarbon chains. As water is polar,
it will only dissolve other polar or ionically bonded substances. Lipids are non-
polar, and this is why they are insoluble in water but can dissolved with non-polar
solvents such as alcohol.
,Describe the structure of a phospholipid. - ANSWER>>Phospholipids contain two
main components: (1) a polar head group joined to (2) a non-polar tail group.
The head is composed of a charged phosphate group and (usually) a nitrogen-
containing group. The head is attracted to polar substances, such as water, and is
therefore hydrophilic (water loving). The tail group is a hydrocarbon-- a molecule
containing an H and C-- composed of non-polar fatty acid chains. The tail repels
water and is therefore hydrophobic (water fearing).
Name the functions of proteins as mentioned in the module. (7) -
ANSWER>>Proteins
-can act as enzymes and regulate metabolic functions,
-store amino acids,
-act as hormones,
-form antibodies for immunological defense,
-act as carriers for transport and also form membrane channels,
-form cell surface receptors to receive chemical messages,
-act as structural molecules for support and movement.
Describe how the shape of a protein is related to its function. (3) -
ANSWER>>Proteins can be assembled into a variety of shapes which allows them
to serve a variety of functions. Some functions of proteins are to make many
needed protective tissues such as skin, hair, and fingernails. Proteins also form
enzymes (catalysts that speed up chemical reactions) and are used to make
needed substances such as hemoglobin, which carries oxygen in red blood cells.
What are the roles of the two major types of nucleic acids? - ANSWER>>There are
two major types of nucleic acids: DNA (deoxyribonucleic acid) and RNA
(ribonucleic acid).
, DNA contains a vast amount of hereditary information and is responsible for the
inheritable characteristics of living organisms.
RNA is responsible for deciphering the hereditary information in DNA and using it
to synthesize proteins.
Describe the structure of DNA and RNA. - ANSWER>>DNA and RNA exist as chains
of nucleotides. The sugar of one nucleotide is linked to the phosphate of the next
nucleotide, while the nitrogenous base protrudes from each sugar in the string.
RNA is most commonly a single chain of nucleotides, whereas DNA is a double
chain held together by hydrogen bonds between protruding bases.
What are some of the main differences between prokaryotic and eukaryotic cells?
- ANSWER>>Prokaryotic cells (also-called prokaryotes) are considered simple cells
and have three defining characteristics: size, non-enclosed genetic material and
lack of organelles and other internal membrane bound structures.
Eukaryotic cells are more complex than prokaryotic cells. Most organisms are
composed of eukaryotic cells. Unlike prokaryotes, eukaryotes are 10-100 times
larger, possess a nuclear membrane (eukaryotic means "true nucleus") and
contain membrane-bound organelles.
What organelles of the cells are complexes of tiny manufacturing plants that
assemble proteins?
1. Endoplasmic reticulum
2. Lysosomes
3. Nucleus
