Biology Long Answer Exam Questions
with Correct Answers
Explain the effect of light intensity and temperature on the rate of photosynthesis. -
ANSWERSLight intensity:
- Rate will increase until it hits a maximum rate
- Will eventually plateau because of other limiting factors
- Different wavelengths will have different effects
CO2 concentration:
- Rate will increase until it hits a maximum rate
- Will eventually plateau because of other limiting factors
Temperature:
- Rate will increase until all reagents are consumed
- Enzymes responsible for photosynthesis denatures after it reaches an optimum
temperature
Describe the use of carbohydrates and lipids for energy storage in animals. -
ANSWERSCarbohydrates:
- Stored as glycogen (liver, muscle cells)
- Short term energy storage
- More soluble in water so transported easily
- More easily digested in the body than lipids so energy is released faster
Lipids:
- Stored as fats in animals
- Long term energy storage (x2)
- More energy than carbohydrates
- Insoluble in water, difficult to transport
- Strong bonds in lipids make it harder to digest
, Explain cohesive and adhesive properties of water. - ANSWERSCohesive:
- Hydrogen bonds between polar water molecules cause them to cohere
- Negative dipole charge on O and positive on H
- Water molecules stick to each other
- Surface tension between molecules allows animals such as water striders to walk over
the surface of ponds even though they are denser than water (optional)
Adhesive:
- Hydrogen bonds between polar water molecules and any other charged or ionic
substance causes them to adhere
- Allows for transport in an aqueous environment
- Dipolarity of water makes them adhere to surfaces that are polar and therefore
hydrophilic
Explain thermal properties of water. - ANSWERS- Hydrogen bonds between water
resists change
- High latent heat of vaporization (water to steam, vice versa)
- High specific heat capacity (energy required to change temperature)
- High latent heat of fusion (ice to water, vice versa)
- Therefore, water provides a stable environment for aquatic organisms
Outline and illustrate the difference between cis and trans fatty acids. - ANSWERSCis:
- Common in nature
- H-atoms on the same side of two C-atoms
- Loosely packed
- Cis-isomer triglycerides are liquid at room temp.
Trans:
- Rare in nature
- H-atoms on the different side of two C-atoms
- Closely packed
- Trans-isomer triglycerides are solid at room temp.
Explain the process in active transport. - ANSWERS- Active transport uses ATP to
pump molecules from a lower concentration gradient to a higher concentration gradient
- Large molecules and ions are transported
- Particle enters pump from lower concentration
- Phosphorylation occurs and adenosine triphosphate becomes adenosine diphosphate
- Pump changes shape
- Particle is released and pump returns to its original shape
with Correct Answers
Explain the effect of light intensity and temperature on the rate of photosynthesis. -
ANSWERSLight intensity:
- Rate will increase until it hits a maximum rate
- Will eventually plateau because of other limiting factors
- Different wavelengths will have different effects
CO2 concentration:
- Rate will increase until it hits a maximum rate
- Will eventually plateau because of other limiting factors
Temperature:
- Rate will increase until all reagents are consumed
- Enzymes responsible for photosynthesis denatures after it reaches an optimum
temperature
Describe the use of carbohydrates and lipids for energy storage in animals. -
ANSWERSCarbohydrates:
- Stored as glycogen (liver, muscle cells)
- Short term energy storage
- More soluble in water so transported easily
- More easily digested in the body than lipids so energy is released faster
Lipids:
- Stored as fats in animals
- Long term energy storage (x2)
- More energy than carbohydrates
- Insoluble in water, difficult to transport
- Strong bonds in lipids make it harder to digest
, Explain cohesive and adhesive properties of water. - ANSWERSCohesive:
- Hydrogen bonds between polar water molecules cause them to cohere
- Negative dipole charge on O and positive on H
- Water molecules stick to each other
- Surface tension between molecules allows animals such as water striders to walk over
the surface of ponds even though they are denser than water (optional)
Adhesive:
- Hydrogen bonds between polar water molecules and any other charged or ionic
substance causes them to adhere
- Allows for transport in an aqueous environment
- Dipolarity of water makes them adhere to surfaces that are polar and therefore
hydrophilic
Explain thermal properties of water. - ANSWERS- Hydrogen bonds between water
resists change
- High latent heat of vaporization (water to steam, vice versa)
- High specific heat capacity (energy required to change temperature)
- High latent heat of fusion (ice to water, vice versa)
- Therefore, water provides a stable environment for aquatic organisms
Outline and illustrate the difference between cis and trans fatty acids. - ANSWERSCis:
- Common in nature
- H-atoms on the same side of two C-atoms
- Loosely packed
- Cis-isomer triglycerides are liquid at room temp.
Trans:
- Rare in nature
- H-atoms on the different side of two C-atoms
- Closely packed
- Trans-isomer triglycerides are solid at room temp.
Explain the process in active transport. - ANSWERS- Active transport uses ATP to
pump molecules from a lower concentration gradient to a higher concentration gradient
- Large molecules and ions are transported
- Particle enters pump from lower concentration
- Phosphorylation occurs and adenosine triphosphate becomes adenosine diphosphate
- Pump changes shape
- Particle is released and pump returns to its original shape
