PORTAGE LEARNING BIOLOGY 171 BIO 171 / BIO171 MODULE 1 EXAM 1

1. True or False: A virus is considered a microorganism. False. Viruses are not living and as such are not considered microorganisms. Viruses can, however, be classified as microbes, a more general term that includes microorganisms and viruses. 2. What is the smallest biological unit of life? A cell. 3. At a generalized level, all cells are comprised of what? Macromolecules* *A student may also answer: Proteins, Lipids, Nucleic acids and Polysaccharides but they must answer with all four to be fully correct. 1. How many different types of amino acids are available from which to make proteins? 20 2. Define an essential amino acid. An essential amino acid cannot be produced by the human body and as such must be take in from the environment through alternative sources (i.e) food. 2. Where can the two major types of nucleic acids be found in the cell and what are their roles? While both DNA and RNA can be found in the nucleus (center of the cell), only RNA is capable of leaving the nucleus. DNA contains a vast amount of hereditary information and is responsible for the inheritable characteristics of living organisms. RNA is responsible for deciphering the hereditary information in DNA and using it to synthesize proteins. 1. Complete the following DNA strand and indicate how many bonds are formed for each complementary pair: 3’ GGTCATCG 5’ 5’ CC AGC 3’ 3’ GGTCATCG 5’ 5’ CCAGTAGC 3’ There are 2 bonds formed between A and T, and 3 bonds between G and C. 1. The plasma membrane (select all that are true): A. Restricts movement of materials in and out of the cell B. Is often a triple layer comprised of lipids C. Prevents essential nutrients from escaping D. Contains hydrophobic tails pointing outward A and C