A students investigated the effects of root space on plant growth. The student grew two groups of plants of the same variety. Both groups received the same amount of water and sunlight and grew in the same type of soil. The plants in group A were grown in cube-shaped containers that were 3 centimeters deep. The plants in Group B were grown in cube-shaped containers that were 10 centimeters deep. The table shows the students observations.

Question

Week cm) cm)
1 2 3
2 3 6
3 5 8
4 7 10
5 8 14
6 10 18

What was the effect of root space on plant growth based on the students investigation? Use the data from the table to support your answer. Explain how you would know whether this effect was likely was due to environmental or genetic factors.

Answer 1

Based on the student's investigation, it can be observed that the plants grown in the deeper containers (Group B, which were 10 centimeters deep) exhibited more growth over the six weeks compared to those grown in the shallower containers (Group A, which were only 3 centimeters deep). The data shows that:

• At Week 1, the plants in Group A grew to 2 cm, while those in Group B grew to 3 cm.
• By Week 6, Group A reached a height of 10 cm, whereas Group B achieved a height of 18 cm.

This indicates a consistent trend whereby Group B outgrew Group A in every week. The plants in the deeper containers had greater height at every observation point, suggesting that increased root space positively affected plant growth.

Data Summary:

• At Week 6: Group A = 10 cm, Group B = 18 cm
• The difference in growth by Week 6: 18 cm (Group B) - 10 cm (Group A) = 8 cm

Conclusion:

The effect of root space on plant growth, as shown in the data, signifies that deeper containers allowed for more extensive root development, which likely contributed to enhanced nutrient uptake and overall plant growth.

Determining Environmental or Genetic Factors:

To ascertain whether the observed differences in plant growth were due to environmental or genetic factors, the following approaches could be considered:

1. Control of Variables: The experiment already controlled several environmental factors such as water, sunlight, and soil type. Therefore, any differences in growth are less likely to be attributed to these factors.

2. Repeating the Experiment: Performing the same experiment with other varieties of plants that have different growth characteristics could determine whether the results hold true across other genetic lines.

3. Genetic Testing: Analyses could be conducted to explore the genetic potential of the plants in both groups. This could involve growing genetically identical plants in both the shallow and deep containers to see if the patterns hold.

4. Observation Across Different Conditions: Conducting the experiment in different environmental conditions or using root barriers to simulate varying root space under controlled environments may provide insights into the specific influences at play.

By considering these methods, one could better discern whether the growth differences were primarily due to the root space provided or if they were influenced by the genetic makeup of the plants.