A Dolphin Built for the Whole Ocean: teacher key

Orcas, grade 7 edition, written for 7th grade. Orcas are the largest dolphins, and they live in every ocean. They differ in size, family life, use of sound and the groups they belong to.

Read the book. Print this page for the key.

Questions and answers

1. What kind of animal is the orca?
   • A very large seal
   • The largest member of the dolphin family (answer)
   • A small kind of shark
2. How does an orca find things in the water?
   • It sniffs the water
   • It follows other animals' tracks
   • It clicks and listens for echoes (answer)
3. Why would an orca not follow one fixed route every year?
   • It moves to where the food is (answer)
   • It cannot swim far
   • It only lives in warm seas
4. In this sentence, what are ecotypes: There are three main ecotypes of orcas in the North Pacific?
   • Three kinds of teeth
   • Three kinds of orcas with different habits (answer)
   • Three ocean routes
5. What stays with an orca mother for life in resident families?
   • Her grown sons and daughters (answer)
   • Her mate
   • Her herring

Words

• ecotypes: different habit groups
• pods: orca family groups
• matriline: mother-led family
• blubber: thick body fat
• echolocation: sensing by echoes