Scarlet Gilia (Ipomopsis Aggregata) Usually Has Red Flowers in an Inflorescence

question 33

Multiple Choice

Scarlet gilia (Ipomopsis aggregata) usually has red flowers in an inflorescence of up to 250 flowers. In certain populations in the Arizona mountains, however, the flowers range from red to pink to white. In early summer, most (but not all) of the flowers were red. Six to eight weeks later, the same individual plants were still present; the flowers ranged from pink to white, and few red flowers were present. The major pollinators early in the season were two species of hummingbirds active during the day; they emigrated to lower elevations, and the major pollinator later in the season was a hawk moth (a type of moth) . The hawk moth was most active at sunset and later, and it preferred light pink to white flowers after dark. When hummingbirds were present, more red flowers than white flowers produced fruit. When only hawk moths were present, more white flowers produced fruit. (K. N. Paige and T. G. Whitham. 1985. Individual and population shifts in flower colour by scarlet gilia: A mechanism for pollinator tracking. Science 227:315-17) .
-Late in the season, when only hawk moths were present, researchers painted the red flowers white. What would you expect?

• A) Unpainted red flowers would produce more fruits than white flowers would.
• B) Red flowers painted white would produce more fruits than red flowers would.
• C) Red and white flowers would produce the same numbers of fruits.
• D) Unpainted red flowers would produce the same number of fruits as the white flowers.

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Definitions:

Hypoid Gear

A type of gear with offset axes of the pinion and gear, allowing for more efficient power transfer and compact design in automotive differentials.

Spiral Bevel Gear

Helical gear set arrangement that has a drive pinion mesh with a crown gear at the radial centerline of the gear.

Torque Capacity

The maximum rotational force that a component or system can handle safely and efficiently.

Torque Proportional

Torque proportional describes a relationship where torque, or the twisting force that causes rotation, varies in direct proportion to another variable, often used in engineering to analyze mechanical systems.