B) Embryonic stem cell research requires the use of human embryos. Its an unethical dilemma.
What hormone helps plants move toward a stimulus?
A.)Ethylene
<u>B.)Auxins</u>
C.)Acids
Auxin moves to the darker side of the plant, causing the cells there to grow larger than corresponding cells on the lighter side of the plant. This produces a curving of the plant stem tip toward the light, a plant movement known as phototropism. Auxin also plays a role in maintaining apical dominance

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Overconsumption – situation where resource use has outpaced the sustainable capacity of the ecosystem. ...
Overpopulation – too many people for the planet to sustain. ...
Acid rain.
Biodiversity loss.
Deforestation.
Desertification.
Global warming/climate change.
Habitat destruction.
source - wikipedia.org