Answer:
c) The presence of an ephiphyseal line
Explanation:
The options should be:
a) the presence of osteoblasts
b) the presence of osteons
c) The presence of an ephiphyseal line
d) the presence of hyaline cartilage on the ends of the bone
Explanation:
In vertebrates, the epiphyseal line is formed once the bone is completely grown. This occurs inside a plate known as the epiphyseal plate.
From the age of 18 to 21, the bone stops growing and the cartilage inside this plate gets replaced by bone. However, bones can keep growing in width until we are approximately 25 years old.
Therefore, the physical sign that indicates that a bone cannot continue longitudinal growth would be the presence of an ephiphyseal line.
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).
Lungs appear collapsed in the fetus because they are filled with amniotic fluid and they have never been inflated with air yet.
Are bunchgrass because they form a kind of ecosystem within the prairie.
