Questions Still Open About Bears: teacher key

Black Bears, grade 12 edition, written for 12th grade and up. From DNA lineages to winter physiology, black bears raise questions scientists are still working on.

Read the book. Print this page for the key.

Questions and answers

1. About when did the two lineages of black bears split, according to genetic studies?
   • About 1.8 thousand years ago
   • About 1.8 million years ago (answer)
   • About 180 years ago
2. What did the USGS-published study in northern New York identify?
   • 47 bear dens
   • 47 salmon runs
   • 47 individual bears from DNA (answer)
3. How did Alaskan black bears' metabolism compare with the usual cooling rule?
   • It slowed far more than the rule predicts (answer)
   • It did not slow
   • It sped up
4. Why may black bears not move well to new areas as habitat shifts?
   • Males have no claws
   • Cubs cannot swim
   • Female bears do not spread far (answer)
5. What is still debated about black bears marking trees?
   • How many trees there are
   • Whether the marks pass on social information (answer)
   • Whether trees grow

Words

• dormancy: winter rest
• lineages: family lines
• metabolism: body's energy use
• implantation: egg settling in