Orcas Across the Oceans: teacher key

Orcas, grade 9 edition, written for 9th grade. Orcas are dolphins found in every ocean. Their groups differ, they find food with sound, and grandmothers help their families.

Read the book. Print this page for the key.

Questions and answers

1. What do the three North Pacific ecotypes mostly differ in?
   • Only their color
   • Appearance, diet, habitat, genetics and behavior (answer)
   • Only their size
2. What did the 2022 Scripps work show about echolocation clicks?
   • They are too quiet to record
   • They are the same for every orca
   • They can tell the three ecotypes apart (answer)
3. Why do orcas not follow a fixed seasonal route?
   • They move to where the food is (answer)
   • They stay in one bay
   • They cannot swim far
4. What is a matriline?
   • A long dive
   • A mother with her sons, daughters and her daughters' calves (answer)
   • A team of hunters
5. What did the 2019 study find about grandmothers past menopause?
   • They leave the pod
   • They hunt alone
   • They boost the survival of their grandcalves (answer)

Words

• ecotypes: habit groups
• echolocation: sensing by echoes
• dialect: a group's sounds
• matriline: mother-led family
• menopause: end of calves