What is thought to have caused the extinction of the dinosaurs?

1, ice ages

2. increase in oxygen

3. asteroid that hit earth

4. rising sea levels

Which animal group is the largest and contains more species from all the other living groups combined? is it mammals or

Iguanas need to live in a habitat that is very warm, so the pet store warms their enclosures with "basking lights" which act as an artificial sun. describe how the three methods of thermal energy transfer may take place within the iguana's enclosure.

Which of the following would be a body response when stepping outside without a coat on a snowy day? a. senaceous glands. secrete more senum b. more liquid is transported by the body to the skin fir insulation c. blood vessels in the skin narrow and contract d. blood vessels in the skin expand