Causes of extinction include four risk categories. Which of the following is not one of the risk categories? A) human risk
B) environmental risk
C) population risk
D) natural catastrophe
E) genetic risk

If scientists are wrong about earth's age based on radioactive material and the decay rates are really much faster, how would nuclear power plants be affected?

Which of the following would most directly interfere with sperm production? ingestion of a substance that mimicked inhibin interruption of sustentocytes' production of abp low sperm count use of synthetic steroids (testosterone)

Compare the lunar phase of the waning crescent to the waxing gibbous. the waning crescent is increasing in illumination and the waxing gibbous is decreasing in illumination. the waning crescent is decreasing in illumination and the waxing gibbous is increasing in illumination. the waning crescent is more than half illuminated and the waxing gibbous is less than half illuminated. the waning crescent is more than half illuminated and the waxing gibbous is more than half illuminated.