Traits and Reproductive Success Practice Test

Two populations of the same ground beetle species live in the same farm field. The only visible trait difference is shell color. After one breeding season, students counted the number of offspring produced per adult.

Which statement is supported by the evidence that traits can influence reproductive success?

Data (same field, same season):

• Dark-shell beetles: 40 adults produced 120 offspring
• Light-shell beetles: 40 adults produced 60 offspring

In the same pond, two types of water plants differ in one physical trait: leaf width. Students measured reproductive success by counting the number of new plantlets produced per parent plant over 6 weeks.

Which claim best links trait to reproductive success using the evidence?

Table: Leaf width and plantlets produced (same pond, 6 weeks)

• Narrow leaves (2 mm): average 6 plantlets per parent
• Wide leaves (8 mm): average 2 plantlets per parent