BIO 156 COMPREHENSIVE REVIEW 2026
VERIFIED QUESTIONS AND SOLUTIONS
◉Describe the structure of an atom Answer: protons
neutrons
electrons
◉Explain why radioisotopes are important to biologists. Answer:
Atoms of a radioisotope have an unstable nucleus that breaks up
spontaneously.
radioisotopes can be used as or in tracers, which are substances
with a detectable component.
PET scan
◉Explain how an acid differs from a base. Answer: The more
concentrated the hydrogen ions are, the lower the pH of the solution.
◉What is the cause and environmental consequence of acid rain?
Answer: Burning fossil fuels such as coal releases sulfur and
nitrogen compounds that affect the pH of rain and other forms of
precipitation.
drastically changes the pH of water in soil, lakes, and streams.
,◉Describe carbohydrates Answer: Simple sugars are called
monosaccharides ( Glucose and fructose).
sucrose is disaccharide.
polysaccharides.
provide energy and structural support for living systems.
◉Describe lipids Answer: can be divided into fats, phospholipids,
steroids, and waxes.
part of it is hydrophobic.
make up part of cell membranes and provide energy.
◉Describe proteins Answer: made up of amino acids.
◉Describe the molecular structure and importance of RNA. Answer:
An RNA molecule is a chain of four kinds of nucleotide monomers,
one of which is ATP. RNA molecules carry out protein synthesis
◉Describe the molecular structure and importance of DNA. Answer:
A DNA molecule consists of two chains of nucleotides twisted into a
double helix.
Each cell starts life with DNA inherited from a parent cell.
, ◉Identify a peptide bond and explain how it is formed. Answer:
covalent bond that links amino acids in a protein
During protein synthesis, a peptide bond forms between the
carboxyl group of the first amino acid and the amine group of the
second
◉Define the primary, secondary (two forms), tertiary, and
quaternary structure of a protein. Answer: 1. primary structure is
order of the amino acids
2. secondary structure has alpha helix and the beta pleated sheet.
tertiary structure interactions between the r- groups of amino acids.
3. quaternary structure is the interaction between multiple
polypeptide chains.
4. making up membrane structure, antibodies, enzymes,
neurotoxins, and hair and nail structure. also used as an energy
source.
◉List the major components of a nucleotide Answer: monomers of
nucleic acids. contains sugar, nitrogen base, and one ore more
phosphate groups.
◉Cite the key features of the Cell Theory. Answer: 1. Every living
organism consists of one or more cells.
VERIFIED QUESTIONS AND SOLUTIONS
◉Describe the structure of an atom Answer: protons
neutrons
electrons
◉Explain why radioisotopes are important to biologists. Answer:
Atoms of a radioisotope have an unstable nucleus that breaks up
spontaneously.
radioisotopes can be used as or in tracers, which are substances
with a detectable component.
PET scan
◉Explain how an acid differs from a base. Answer: The more
concentrated the hydrogen ions are, the lower the pH of the solution.
◉What is the cause and environmental consequence of acid rain?
Answer: Burning fossil fuels such as coal releases sulfur and
nitrogen compounds that affect the pH of rain and other forms of
precipitation.
drastically changes the pH of water in soil, lakes, and streams.
,◉Describe carbohydrates Answer: Simple sugars are called
monosaccharides ( Glucose and fructose).
sucrose is disaccharide.
polysaccharides.
provide energy and structural support for living systems.
◉Describe lipids Answer: can be divided into fats, phospholipids,
steroids, and waxes.
part of it is hydrophobic.
make up part of cell membranes and provide energy.
◉Describe proteins Answer: made up of amino acids.
◉Describe the molecular structure and importance of RNA. Answer:
An RNA molecule is a chain of four kinds of nucleotide monomers,
one of which is ATP. RNA molecules carry out protein synthesis
◉Describe the molecular structure and importance of DNA. Answer:
A DNA molecule consists of two chains of nucleotides twisted into a
double helix.
Each cell starts life with DNA inherited from a parent cell.
, ◉Identify a peptide bond and explain how it is formed. Answer:
covalent bond that links amino acids in a protein
During protein synthesis, a peptide bond forms between the
carboxyl group of the first amino acid and the amine group of the
second
◉Define the primary, secondary (two forms), tertiary, and
quaternary structure of a protein. Answer: 1. primary structure is
order of the amino acids
2. secondary structure has alpha helix and the beta pleated sheet.
tertiary structure interactions between the r- groups of amino acids.
3. quaternary structure is the interaction between multiple
polypeptide chains.
4. making up membrane structure, antibodies, enzymes,
neurotoxins, and hair and nail structure. also used as an energy
source.
◉List the major components of a nucleotide Answer: monomers of
nucleic acids. contains sugar, nitrogen base, and one ore more
phosphate groups.
◉Cite the key features of the Cell Theory. Answer: 1. Every living
organism consists of one or more cells.
