Question
Which activity directly contributes the most to recent increases in atmospheric CO2 concentrations?
A. Landfills
B. Planting trees
C. Cattle rearing
D. Burning of fossil fuels
Answer/Explanation
Question
Humans have been improving crop species for thousands of years by cross-breeding plants with
desirable characteristics. The photograph shows the changes in dry cobs of corn (Zea mays) over
10 000 years.
What is the name of the process that was used to produce modern corn?
A. Selective breeding
B. Adaptive radiation
C. Discontinuous variation
D. Natural selection
Answer/Explanation
Question
Which encircled area shows a clade?
Answer/Explanation
Question
The diagram shows a simplified carbon cycle.