Which of the following scenarios represents change to an ecosystem brought about by biotic factors?
a.
a wildfire caused by lightning striking a tree
b.
a flood caused by a severe storm
c.
a landslide caused by cattle overgrazing
d.
a volcano

The image shows ekgs of a person with normal heart waves and of a person having tachycardia. based on this image, what kind of condition is tachycardia? a. the heart beats abnormally fast. b. the heart beats abnormally slow. c. the right atrium of the heart stops working. d. the left ventricle pumps less blood to the aorta.

What kind of crystalline solid is graphite? o a. molecular solid b. metallic solid o c. network solid d. ionic solid

Which of the following best describes the relationship between glucose and complex molecules such as hormones?