Question

Describe the trends shown by the regression lines in your scatter plot. (a) Compare the relationship between the increasing concentration of CO₂ and the dry mass of corn to that for velvetleaf. (b) Considering that velvetleaf is a weed invasive to cornfields, predict how increased CO₂ concentration may affect interactions between the two species.

Short answer

1. The dry mass of the corn is lesser compared to the velvetleaf because the velvetleaf utilizes CO₂and has more dry mass.
2. The increase in carbon dioxide, in turn, increases the competition between the weed species velvetleaf and corn.

Step-by-step solution

Carbon dioxide’s role in the photosynthesis  

Carbon dioxide from the atmosphere is utilized in the process of photosynthesis. Carbon dioxide is used to make food for the plants. Carbon dioxide can increase the growth of plants.

Explanation for part “a”

The dry weight of corn increases due to the rise in carbon dioxide since it acts as a fuel to produce the starch required for plant growth.

The carbon dioxide concentration and the dry weight of corn are directly related to each other. The dry mass of the velvet plant increases more than the corn plant does due to more utilization of carbon dioxide by the weed plant.

Explanation for part “b”

The weed species that grows along with the corn plant is the velvet plant. Even though it is a weed plant, the increase in carbon dioxide tends to increase the dry weight of the weed plant. The weed plant also tends to consume carbon dioxide and grow similar to the corn plant.

The interaction between the weed species and the corn plant is a competitive interaction since the weed plant tries to utilize more carbon dioxide and increase its growth, which results in the inhibition of the growth of corn. A negative trend is seen in the interaction of these two species.