Bio 211 Chapter 1 Test Questions and Correct Answers

What is the main difference between the flow of energy and the flow of nutrients through an ecosystem? energy flow is one-way; nutrients can be recycled Energy enters most ecosystems as ____________ and exits as _______. sunlight, heat What are the 2 components of the Cell Theory? all living things are made of cells; cells come from preexisting cells Eukaryotic cells differ from prokaryotic cells in having membrane-enclosed organelles What does it mean to say that the genetic code is universal? all living things decode the genetic message (DNA) in the same way In order to regulate cellular activities cells regulate _________. enzymes One way that enzymes are regulated is through feedback inhibition Evolution accounts for the _______ and _________ of life. unity and diversity Evolution by natural selection results in organisms that are _________ to their environment. adapted One lineage becomes 2 lineages (now 2 species) when populations of a single species ____________. become isolated and no longer exchange genes Life began on earth approximately 4.0 bya The first photosynthetic organisms to evolve were __________. Cyanobacteria What are the 4 basic aspects of living things whose origins we must explain to know how life began? organic molecules, metabolism, cells, reproduction and genetics Which of the following is NOT correctly matched with its time of appearance? first eukaryotes - 3.0 bya