Compares how plants and animals vary when their environments are essentially the same except that one is hot and dry and the other cold, such as a hot river in

Animals have learned to survive in some incredibly harsh conditions—from frozen habitats to the scorching heat of the desert. Readers learn about how some ani

Chapter 1 Temperature Regulation in Animals There are, broadly speaking, two kinds of animals with regard to body temperature: exothermic (cold-blooded) and end

Updated for 2020, Early readers learn about different animal habitats.