Question

Again, imagine phase portrait arrows that start directly on the zero growth isocline for the pathogen (the orange line). The arrowheads would point:

1) Up, always
2) Down, always
3) Up, if N₂ is less than its steady state value; down, if N₂ is greater than its steady state value
4) Down, if N₂ is less than its steady state value; up, if N₂ is greater than its steady state value

Answer 1

The arrows will point up if N₂ is less than its steady state value and down if N₂ is greater than its steady state value on the zero growth isocline.

Step-by-step explanation:

The correct answer is 3) Up, if N₂ is less than its steady state value; down, if N₂ is greater than its steady state value.

In a phase portrait, the arrows represent the direction that the system will move in. When the arrows start directly on the zero growth isocline for the pathogen, which is the orange line, the arrowheads will point up if the population, represented by N₂, is less than its steady state value. This indicates that the population is increasing. On the other hand, if N₂ is greater than its steady state value, the arrowheads will point down, indicating that the population is decreasing.

For example, let's say the steady state value of N₂ is 100. If the population is currently at 80, the arrowhead will point up because the population will continue to increase. However, if the population is at 120, the arrowhead will point down because the population will decrease and move towards its steady state value.