Two Juniper Trees (Juniperus Scopulorum and J

question 56

Multiple Choice

Two juniper trees (Juniperus scopulorum and J. monosperma) have overlapping geographic ranges. Pollen grains (which contain sperm cells) from one species are unable to germinate and make pollen tubes on female ovules (which contain egg cells) of the other species. Which of the following isolating mechanisms keeps the two species separate?

• A) habitat isolation
• B) temporal isolation
• C) gametic isolation
• D) behavioral isolation

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Definitions:

Photosynthesis

The biochemical process by which green plants and some other organisms convert light energy into chemical energy stored in carbohydrates.

Physiological Response

An automatic reaction or change in bodily function in response to a stimulus, part of an organism's mechanism for maintaining homeostasis.

Plant Hormones

Chemical substances produced within plants that regulate growth, development, and other physiological processes.

Nucleus

The membrane-bound organelle in eukaryotic cells that contains the genetic material (DNA).