Scientists are examining the possible role of a large asteroid in the Cretaceous mass extinction event. A large asteroid strike
would likely have caused rapid climate cooling and diffusion of sunlight. Which of the following statements are the best null and alternative hypotheses when scientists look at the geologic evidence of extinction related to the asteroid strike?
A) Null: The rate of extinction would be steady over the entire length of time the climate was altered.
Alternative: The rate of extinction would be greatest immediately before the asteroid strike.
B) Null: The rate of extinction would gradually decrease over the entire length of time the climate was altered.
Alternative: The rate of extinction would be at its lowest immediately after the asteroid strike.
C) Null: The rate of extinction would be steady over the entire length of time the climate was altered.
Alternative: The rate of extinction would be greatest immediately after the asteroid strike.
D) Null: The rate of extinction would gradually decrease over the entire length of time the climate was altered.
Alternative: The rate of extinction would be at its greatest immediately after the asteroid strike.
Blood flow is the volume of blood flowing through any given vessel, or through the circulatory system as a whole, per minute. This is also called cardiac output, and it's determined by the blood volume pumped during one beat and the number of beats per minute.
Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. Chloroplasts absorb sunlight and use it in conjunction with water and carbon dioxide gas to produce food for the plant.
