Why are modern homes more likely to have higher indoor pollution? a. they use kerosene heaters b. they use asbestos to prevent fires. c. they have central heating and air conditioning d. they are tightly sealed from the outside

The seed coat's most important function is to provide a) a nonstressful environment for the megasporangium. b) the means for dispersal. c) dormancy. d) a nutrient supply for the embryo. e) desiccation resistance.

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

The smallest parts of these that retain their original properties are called