HESI BIOLOGY EXAM Q’S & A’S
what is the hierarchic organizational system for nomenclature? - Answer- kingdom,
phylum, class, order, family, genus, species
what are the steps of the scientific method? - Answer- observation, hypothesis,
experiment, conclusion
what is the chemical composition of water? - Answer- two hydrogen atoms covalently
bonded to an oxygen atom
what is the most significant aspect of water? - Answer- polarity of its bond
what does water's polarity allow for? - Answer- hydrogen bonding and versatile
solvent
what does hydrogen bonding in water cause? - Answer- high specific heat value,
strong cohesive and strong adhesive properties
what is the definition of specific heat? - Answer- the amount of heat necessary to
raise the temperature of one gram of that molecule by one degree Celsius
what is good to note about water's specific heat value? - Answer- it is relatively high
what does a relatively high specific heat value allow for? - Answer- resists shifts in
temperature
how does the high specific heat value of water play a role in the biosphere? -
Answer- oceans and large bodies of water are able to stabilize climates
what is cohesion? - Answer- the ability of a molecule to stay bonded or attracted to
another molecule of the same substance
what is adhesion? - Answer- the ability of a molecule to bond or attract other
molecules or substances
what occurs when water freezes? - Answer- lattice crystal is formed, molecules
spread apart
what are the most important biological molecules? - Answer- carbohydrates, lipids,
proteins, nucleic acids
what are carbohydrates? - Answer- generally long chains or polymers of sugars
what are the most important functions of carbohydrates? - Answer- storage,
structure, energy
what is DNA short for? - Answer- dioxyribonucleic acid
, what is RNA short for? - Answer- ribonucleic acid
what forms the backbone of DNA and RNA? - Answer- sugar-phosphate backbone
what is another term for fats? - Answer- lipids
what are the types of lipids? - Answer- fatty acids, phospholipids, steroids
what are the two types of fatty acids? - Answer- saturated and unsaturated
what is significant about saturated fat? - Answer- no double bonds in their
hydrocarbon tail
what is significant about unsaturated fat? - Answer- one or more double bonds in
their hydrocarbon tail
is saturated fat liquid or solid at room temperature? - Answer- solid
is unsaturated fat liquid or solid at room temperature? - Answer- liquid
what are cardiovascular problems associated with? - Answer- diets containing high
quantities of saturated fats
what are phospholipids? - Answer- two fatty acids of varying lengths bonded to a
phosphate group
what part of a phospholipid is charged and uncharged? - Answer- phosphate head -
charged
hydrocarbon tail - uncharged
is the phosphate head of a phospholipid water-soluble or not? - Answer- it is water-
soluble
is the hydrocarbon tail of a phospholipid water-soluble or not? - Answer- it is not
water-soluble
what are phospholipids important for? - Answer- formation of cellular membranes
what is the cellular membrane? - Answer- barrier that protects the cell
what are steroids important for? - Answer- components of membranes and
precursors to significant hormones and drugs
what are proteins most significant for? - Answer- cellular function
what are proteins made of? - Answer- 20 molecules called amino acids
what is the largest biological molecule? - Answer- protein
what is the hierarchic organizational system for nomenclature? - Answer- kingdom,
phylum, class, order, family, genus, species
what are the steps of the scientific method? - Answer- observation, hypothesis,
experiment, conclusion
what is the chemical composition of water? - Answer- two hydrogen atoms covalently
bonded to an oxygen atom
what is the most significant aspect of water? - Answer- polarity of its bond
what does water's polarity allow for? - Answer- hydrogen bonding and versatile
solvent
what does hydrogen bonding in water cause? - Answer- high specific heat value,
strong cohesive and strong adhesive properties
what is the definition of specific heat? - Answer- the amount of heat necessary to
raise the temperature of one gram of that molecule by one degree Celsius
what is good to note about water's specific heat value? - Answer- it is relatively high
what does a relatively high specific heat value allow for? - Answer- resists shifts in
temperature
how does the high specific heat value of water play a role in the biosphere? -
Answer- oceans and large bodies of water are able to stabilize climates
what is cohesion? - Answer- the ability of a molecule to stay bonded or attracted to
another molecule of the same substance
what is adhesion? - Answer- the ability of a molecule to bond or attract other
molecules or substances
what occurs when water freezes? - Answer- lattice crystal is formed, molecules
spread apart
what are the most important biological molecules? - Answer- carbohydrates, lipids,
proteins, nucleic acids
what are carbohydrates? - Answer- generally long chains or polymers of sugars
what are the most important functions of carbohydrates? - Answer- storage,
structure, energy
what is DNA short for? - Answer- dioxyribonucleic acid
, what is RNA short for? - Answer- ribonucleic acid
what forms the backbone of DNA and RNA? - Answer- sugar-phosphate backbone
what is another term for fats? - Answer- lipids
what are the types of lipids? - Answer- fatty acids, phospholipids, steroids
what are the two types of fatty acids? - Answer- saturated and unsaturated
what is significant about saturated fat? - Answer- no double bonds in their
hydrocarbon tail
what is significant about unsaturated fat? - Answer- one or more double bonds in
their hydrocarbon tail
is saturated fat liquid or solid at room temperature? - Answer- solid
is unsaturated fat liquid or solid at room temperature? - Answer- liquid
what are cardiovascular problems associated with? - Answer- diets containing high
quantities of saturated fats
what are phospholipids? - Answer- two fatty acids of varying lengths bonded to a
phosphate group
what part of a phospholipid is charged and uncharged? - Answer- phosphate head -
charged
hydrocarbon tail - uncharged
is the phosphate head of a phospholipid water-soluble or not? - Answer- it is water-
soluble
is the hydrocarbon tail of a phospholipid water-soluble or not? - Answer- it is not
water-soluble
what are phospholipids important for? - Answer- formation of cellular membranes
what is the cellular membrane? - Answer- barrier that protects the cell
what are steroids important for? - Answer- components of membranes and
precursors to significant hormones and drugs
what are proteins most significant for? - Answer- cellular function
what are proteins made of? - Answer- 20 molecules called amino acids
what is the largest biological molecule? - Answer- protein
