Why are the lungs made up of these progressively smaller tubes and then millions of tiny alveoli rather than each lung just being a large empty sack?

How many copies of each chromosomes should be present in each of the 4 final haploid versions of gamete?

Which statements describe resources? one of the factors people use when deciding where they will live is the availability of resources. renewable resources have little value for people. resources are unevenly distributed throughout the world. energy is the world resource which has the highest use. the use of nonrenewable resources has decreased in recent history. the use of resources is evenly distributed throughout the world. the world's oil supply will last for the next forty years if its use continues as expected.

18. which statement about cancer is true?