Which of the following adaptations is characteristic of crocodiles?
a. scaly skin
c. four-chambered heart
b. ectothermic
d. all of the above

Dna is colied into chromosomes in a cell

Which best describes how the common cold spreads in the human body? a bacteria burst out of normal cells killing them b viruses replicate inside respiratory cells c bacteria inject dna into normal cells d viruses insert dna into bacteria

Which event would lead to primary succession of a forest?