Since parent of both Justin and his wife Brittany have blood group ab, this means Justin is homozygous(aa) for blood group a and similarly his his wife Brittany is also homozygous (bb) for blood group b. Therefore, Justin and Brittany's son Theodore will certainly have ab blood group.
To smell and feel surfaces and sense temperatures
1. The correct answer is pH.
The activity of the enzymes might be affected by environmental changes such as change in pH. Each enzyme has the point when it is the most active and this value is known as the optimum pH. Extremely high or low pH values can lead to loss of enzyme activity and stability.
Phosphofructokinase is sensitive to acidity, meaning that it is inhibited by low pH levels.
2. The correct answer is temperature.
Enzyme is sensitive to the environmental conditions such as temperature changes.
Temperature is a factor that usually increases the rate of enzyme-catalyzed reactions by increasing the activity of enzymes. But, after reaching the optimum temperature, reaction rate abruptly declines. This happens because enzymes are deactivated or denatured at a certain temperature (above 40° C).