Note the presence of air sacs (воздушные мешки) which enable double respiration.

This workbook typically features tasks on or Animal Behavior towards the end of the book.

Describing food chains or the role of animals in a specific biocenosis. Key Answers: Producers (plants) →right arrow Primary Consumers (herbivores) →right arrow Secondary Consumers (predators). How to confirm your assignment:

They lack a urinary bladder (to reduce weight for flight). 2. Workbook by V.V. Latyushin and V.A. Shapkin

Comparing the skeletons or organ systems of different vertebrates.

In this version, page 87 often deals with or Mammals .

If you are using the blue "Line of Life" (Линия жизни) series, page 87 usually covers or

Lab work or filling out a table on "Internal Structure of Birds." Key Answers: