The cycads, a mostly tropical phylum of gymnosperms, evolved about 300 million years ago and were dominant forms during the Age of the Dinosaurs. Though their sperm are flagellated, their ovules are pollinated by beetles. These beetles get nutrition (they eat pollen) and shelter from the microsporophylls. Upon visiting megasporophylls, the beetles transfer pollen to the exposed ovules. In cycads, pollen cones and seed cones are borne on different plants. Cycads synthesize neurotoxins, especially in the seeds, that are effective against most animals, including humans.
Which feature of cycads distinguishes them from most other gymnosperms?
1. They have exposed ovules.
2. They have flagellated sperm.
3. They are pollinated by animals.
A) 1 only
B) 2 only
C) 3 only
D) 2 and 3
E) 1, 2, and 3
Answer: D
Which feature of cycads makes them similar to many angiosperms?
1. They have exposed ovules.2. They have flagellated sperm.
3. They are pollinated by animals.
A) 1 only
B) 2 only
C) 3 only
D) 2 and 3
E) 1, 2, and 3
Answer: C
If the beetles survive by consuming cycad pollen, then whether the beetles should be considered mutualists with, or parasites of, the cycads depends upon A) the extent to which their overall activities affect cycad reproduction.
B) the extent to which the beetles are affected by the neurotoxins.C) the extent to which the beetles damage the cycad flowers.
D) the distance the beetles must travel between cycad microsporophylls and cycad megasporophylls.
Answer: A
On the Pacific island of Guam, large herbivorous bats called "flying foxes" commonly feed on cycad seeds, a potent source of neurotoxins. The flying foxes do not visit male cones. Consequently, what should be true?
A) The flying foxes are attracted to cycad fruit, and eat the enclosed seeds only by accident.
B) Flying foxes are highly susceptible to the effects of the neurotoxins.C) The flying foxes assist the beetles as important pollinating agents of the cycads.
D) Flying foxes can be dispersal agents of cycad seeds if the seeds sometimes get swallowed whole (in other words, without getting chewed).
Answer: D
If one were to erect a new taxon of plants that included all plants that are pollinated by animals, and only plants that are pollinated by animals, then this new taxon would be
A) monophyletic.
B) paraphyletic.C) polyphyletic.
D) identical in composition to the phylum Anthophyta.
E) identical in composition to the phylum Cycadophyta.
Answer: C
Learn More :
Biology
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