Abscisic acid, also known as ABA, is a plant hormone. Scientists have linked ABA with the opening and closing of the small air passageways in plant leaves called stoma. What environmental condition is MOST likely to trigger the closing of leaf stoma?
A)
wind
B)
heat
C)
darkness
D)
lack of moisture

Question

Abscisic acid, also known as ABA, is a plant hormone. Scientists have linked ABA with the opening and closing of the small air passageways in plant leaves called stoma. What environmental condition is MOST likely to trigger the closing of leaf stoma?
A)
wind	
B)
heat	
C)
darkness	
D)
lack of moisture

anonymous · Answer

I'm pretty sure it's D because none of the others make much sense, but we've never learned this, so I have no idea.

anonymous · Answer

most probably lack of moisture, cause in the absence of the water, the plant would most likely want to retain the little left by preventing water loss through its stoma

anonymous · Answer

Okay, thank you.  That makes sense.  Would you mind helping me with some more questions.

anonymous · Answer

i'll try

anonymous · Answer

Okay, hold on a second, please.

anonymous · Answer

Fossilized remains of ancient organisms are considered by many scientists to be the strongest evidence that species change over time. Besides fossils, what is another strong source of evidence that organisms evolve over time?
A)
oral histories of ancient peoples	
B)
similarities in behavior in related species	
C)
DNA sequences of populations that are closely related	
D)
similarities in the genetic mutation rates of closely related species

anonymous · Answer

i would go with C, i think thats the best option

anonymous · Answer

Okay, thank you.  I was leaning toward either B or C, but I guess you would have to get really technical to decide whether an organism was evolved or not besides looking at their behavior.  I have one more question.

anonymous · Answer

Why are many bacterial infections more difficult to treat now than they were fifty years ago?
A)
Because there are more types of bacteria now.	
B)
Because bacteria have evolved resistance to antibiotics.	
C)
Because bacteria reproduce at greater rates than in the past, since there are more people on earth.	
D)
Because treatment of virus infections consumes many antibiotics that were formerly used only for bacteria.

anonymous · Answer

its B, most bacteria have become resistant to antibiotic, each time an antibiotic is produce, they modify their DNA over time to for resistant species

anonymous · Answer

Great, thanks so much for clarifying!

anonymous · Answer

anytime