OCR A LEVEL BIOLOGY EXAM
QUESTIONS AND ANSWERS FINAL
UPDATED STUDY GUIDE
What is the significance of water's 'high specific heat capacity' ? (in 2
environments) - ✔✔✔ANSWER-Helps maintain a stable temperature
in aquatic and cellular environments
What is the significance of water's 'high latent heat of evaporation' ?
(e.g.) - ✔✔✔ANSWER-Evaporation has a cooling effect e.g. through
sweating
What is the significance of water being 'cohesive' ? (when moving up...)
- ✔✔✔ANSWER-Water molecules 'stick' (cling) to each other when
moving up the xylem
What is the significance of water being 'adhesive' ? (e.g.) -
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,✔✔✔ANSWER-Water molecules are attracted to (cling to) dissimilar
substances e.g. the xylem wall
Water is a useful biological 'solvent'. This is because it can... (2
substances) - ✔✔✔ANSWER-Dissolve ionic and polar substances
Name the chemical elements that make up carbohydrates, lipids (+
steroids), proteins and nucleic acids - ✔✔✔ANSWER-Carbohydrates -
C, H, O
Lipids (+ steroids) - C, H, O
Proteins - C, H, O, N, S
Nucleic acids - C, H, O, N, P
Monosaccharides (also known as...) are... - ✔✔✔ANSWER-Simple
sugars, the simplest carbohydrate
Water molecules consist of... - ✔✔✔ANSWER-Two hydrogen atoms
covalently bound to an oxygen atom
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, Oxygen is more... (...), than hydrogen (...) - ✔✔✔ANSWER-
Electronegative (delta -ve), (delta +ve)
Hence, water is described as being... - ✔✔✔ANSWER-Polar
As opposites attract, there is a force of attraction between... water
molecules known as a... - ✔✔✔ANSWER-Different, Hydrogen bond
Name 6 biologically important properties of water. -
✔✔✔ANSWER- Liquid medium, High specific heat capacity, High
latent heat of evaporation, Cohesive, Adhesive, Solvent
What is the significance of water being a 'liquid medium' ? (3 points) -
✔✔✔ANSWER-It provides habitat, It provides a site for chemical
reactions, It is used in transport
What is a hexose? - ✔✔✔ANSWER-A monosaccharide with 6 carbon
atoms
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QUESTIONS AND ANSWERS FINAL
UPDATED STUDY GUIDE
What is the significance of water's 'high specific heat capacity' ? (in 2
environments) - ✔✔✔ANSWER-Helps maintain a stable temperature
in aquatic and cellular environments
What is the significance of water's 'high latent heat of evaporation' ?
(e.g.) - ✔✔✔ANSWER-Evaporation has a cooling effect e.g. through
sweating
What is the significance of water being 'cohesive' ? (when moving up...)
- ✔✔✔ANSWER-Water molecules 'stick' (cling) to each other when
moving up the xylem
What is the significance of water being 'adhesive' ? (e.g.) -
Page | 1
,✔✔✔ANSWER-Water molecules are attracted to (cling to) dissimilar
substances e.g. the xylem wall
Water is a useful biological 'solvent'. This is because it can... (2
substances) - ✔✔✔ANSWER-Dissolve ionic and polar substances
Name the chemical elements that make up carbohydrates, lipids (+
steroids), proteins and nucleic acids - ✔✔✔ANSWER-Carbohydrates -
C, H, O
Lipids (+ steroids) - C, H, O
Proteins - C, H, O, N, S
Nucleic acids - C, H, O, N, P
Monosaccharides (also known as...) are... - ✔✔✔ANSWER-Simple
sugars, the simplest carbohydrate
Water molecules consist of... - ✔✔✔ANSWER-Two hydrogen atoms
covalently bound to an oxygen atom
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, Oxygen is more... (...), than hydrogen (...) - ✔✔✔ANSWER-
Electronegative (delta -ve), (delta +ve)
Hence, water is described as being... - ✔✔✔ANSWER-Polar
As opposites attract, there is a force of attraction between... water
molecules known as a... - ✔✔✔ANSWER-Different, Hydrogen bond
Name 6 biologically important properties of water. -
✔✔✔ANSWER- Liquid medium, High specific heat capacity, High
latent heat of evaporation, Cohesive, Adhesive, Solvent
What is the significance of water being a 'liquid medium' ? (3 points) -
✔✔✔ANSWER-It provides habitat, It provides a site for chemical
reactions, It is used in transport
What is a hexose? - ✔✔✔ANSWER-A monosaccharide with 6 carbon
atoms
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