Explain how the movement of hydrogen and potassium ions across the membranes of guard cells opens and closes the
stomata. What will be an ideal response?
Concepts to Consider: Light triggers H+ to be pumped out of guard cells; K+ can then be
actively transported into guard cells; this results in the entry of water by osmosis into guard
cells; turgidity of guard cells is increased, causing them to change shape and open pore.
There appears to be a reversal of this process for stomatal closure.
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Honeybee workers spend their first few weeks as young adults tending the colony's brood, then later shift jobs to foraging for food outside the colony
When researchers fed the young bees candy spiked with the molecule ethyl oleate, the young bees continued to babysit and delayed the job shift to foraging. What would it require to demonstrate that ethyl oleate normally acts as a pheromone, not as an endocrine or paracrine signal? A. It would require demonstration that ethyl oleate binds to a receptor and initiates a series of responses. B. It would require demonstration that ethyl oleate is released by another individual of the same species. C. It would require demonstration that ethyl oleate is released by a predator and causes a behavioral change in the prey.
____ radiate from the center of the cell and anchor the ER, Golgi complex, lysosomes, and secretory
vesicles in place.
a. Microfilaments b. Microtubules c. Laminins d. Actins e. Cytokeratins
Arrange the following terms from most inclusive to least inclusive
1. embryophytes 2. green plants 3. seedless vascular plants 4. ferns 5. tracheophytes A) 1, 2, 5, 3, 4 B) 2, 1, 5, 3, 4 C) 2, 5, 1, 3, 4 D) 1, 4, 2, 5, 3
Which of the following statements about ecological pyramids is true?
A. A pyramid of organism numbers will always have a large base and a small top. B. The limited number of trophic levels in an ecological pyramid is due to increasing complexity and size of organisms at each greater trophic level. C. Pyramids built upon the biomass of organisms at each level eliminate size as a factor. D. Energy gains between trophic levels occur based upon biomass conversion. E. None of the choices are true.