Biology Exam: Chapters 6 & 7

Transcription

1 Biology Exam: Chapters 6 & 7 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which of the following compounds may be polymers? A) carbohydrates C) proteins B) nucleic acids D) all of these 2. Carbon compounds that come from living organisms are called compounds. A) water C) homogeneous B) organic D) biological 3. How many electrons can a carbon atom share? A) one C) three B) two D) four 4. Which of the following is a chemical reaction? A) tearing paper into strips B) burning paper C) picking up iron filings with a magnet D) mixing salt and sugar in the same container 5. represents a formula for a chemical compound. A) H C) P B) C D) H 2 O 6. The nucleus of an atom contains. A) protons and neutrons C) protons and electrons B) neutrons and electrons D) protons, neutrons, and electrons 7. What are the basic building blocks of proteins? A) nucleic acids C) amino acids B) peptide bonds D) glycerol and fatty acids 8. Water dissolves many ionic and molecular compounds because of its. A) ionic bonding C) covalent bonding B) polarity D) hydroxide bonding 9. A chlorine atom becomes a chloride ion when it. A) gains an electron C) gains a neutron B) loses an electron D) loses a proton 10. The various enzymes in our bodies are. A) lipids C) nucleotides B) carbohydrates D) proteins 11. Glucose and fructose, with the formula C 6 H 12 O 6, differ in. A) numbers of atoms C) kinds of atoms B) arrangement of atoms D) arrangement of electrons 12. A very strong base might have a ph of. A) 3 C) 9 B) 5 D) The total number of atoms in a molecule of sucrose, C 12 H 22 O 11, is. A) 11 C) 22 B) 12 D) 45

2 14. An atom of fluorine has nine electrons. Its second energy level has. A) two electrons C) seven electrons B) eight electrons D) nine electrons 15. Which of the images in Figure 6-4 depicts dynamic equilibrium? Figure 6-4 A) A C) C B) B D) D 16. All living things are made up of. A) cells C) wastes B) cork D) cellulose 17. One advantage of electron microscopes over light microscopes is their. A) size C) two-dimensional image B) higher magnification D) use of live specimens 18. If a cell contains a nucleus, it must be a(n). A) plant cell C) animal cell B) eukaryotic cell D) prokaryotic cell 19. Because cells have a watery environment both inside and outside, the polar ends of the phospholipids in the plasma membrane form layers A) several C) double B) triple D) single 20. The fluid mosaic model describes a structure with. A) polar layers on the outside and nonpolar layer on the inside B) nonpolar layers on the outside and a polar layer on the inside C) polar layers on both inside and outside D) nonpolar layers on both inside and outside 21. A cell's contents would be the same as its surrounds, were it not for. A) plasmolysis C) phagocytosis B) selective permeability D) cell walls 22. A plasma membrane is made up of a(n). A) cholesterol layer C) phospholipid bilayer B) enzyme bilayer D) protein layer

3 Figure What is the approximate size of A in Figure 7-3? A) 400 µm C) 50 µm B) 700 µm D) 1000 µm Figure Which structure in Figure 7-6 is the cell control center? A) A C) I B) G D) M 25. Which structure in Figure 7-6 is responsible for chemical reactions? A) A C) J B) E D) L 26. Which structure in Figure 7-6 transforms sugars into energy the cell can use? A) C C) J B) G D) K

4 27. Which parts of Figure 7-6 are in a prokaryotic cell? A) D and M C) C and J B) A and K D) G and L Matching Match each item with the correct statement below. A) cellulose E) polymer B) polar molecule F) solution C) nucleus G) enzyme D) peptide bond H) metabolism 28. glucose polymer that forms the cell walls of plants 29. large molecule formed when many smaller molecules bond together 30. molecule with unequal distribution of charge 31. protein that speeds up a chemical reaction 32. bond formed between amino acids 33. all the chemical changes that occur within an organism 34. mixture in which one substance is distributed evenly in another 35. center of an atom Completion Complete each statement. 36. The smaller subunits that make up nucleic acids are. 37. Atoms of the same element with different numbers of neutrons are. 38. In a cell, the sites of protein synthesis are the. 39. The small, membrane-bound structures inside a cell are. 40. The movement of materials into and out of the cells is controlled by the. 41. In plants, the structures that transform light energy into chemical energy are called. 42. The folded system of membranes that forms a network of interconnected compartments inside the cell is called the. 43. A structure outside the plasma membrane in plant and bacterial cells is the. 44. In the chemical reaction 6CO H 2 O + sunlight C 6 H 12 O 6 + 6O 2 + 6H 2 O, 1 molecule of sugar is represented by.

5 Short Answer Choose any FIVE of the below to answer. If you answer more than five short answer questions, only the first five will be graded. Figure What types of biological compounds are A and B of Figure 6-2? Of what biomolecule are these a subunit? Indicator Color at lower ph values Table 6-1 ph range of color transition Color at higher ph values Methyl red Red Yellow Litmus Red Blue Bromothymol blue Yellow Blue Phenol red Yellow Red Phenolphthalein Colorless Red 46. Refer to Table 6-1 of acid-base indicators. A small volume of dilute hydrochloric acid is placed in a beaker, and two drops of phenolphthalein are added. The solution remains colorless. A dilute solution of sodium hydroxide is then added drop by drop until a color change occurs. In what ph range does the color change occur? Describe the color change that occurs.

6 Two students carry out an investigation to determine the action of the enzyme pepsin on protein digestion in the human stomach. They know that gastric juice in the stomach contains water, pepsin, and hydrochloric acid. They decide to use small, equal-sized pieces of cooked egg white as the protein to be digested. They set up four test tubes and place equal, small amounts of egg white in each test tube. Then they fill each test tube with a different liquid to a height of 3 cm. To test tube 1 they add water, to test tube 2 they add dilute hydrochloric acid (HCl), to test tube 3 they add pepsin in water, and to test tube 4 they add pepsin and dilute hydrochloric acid. They place the four test tubes in an incubator set at 37ºC (body temperature). After one day, they observe the results. They return the test tubes to the incubator and observe them again the next day. Table 6-2 is the record of the results. Table 6-2 Test tube 1 day 2 days 1. egg + water no change no change 2. egg + HCl no change no change 3. egg + pepsin liquid slightly cloudy, egg white solid liquid cloudy, egg white still solid 4. egg + pepsin + HCl liquid cloudy, pieces of egg smaller liquid very cloudy, almost no egg remains 47. Write a conclusion to the experiment. Base your conclusion on the experimental results shown in Table 6-2. Be sure to indicate which test tube is the control. Figure Is the cell shown in Figure 7-1 a prokaryote or eukaryote? Identify the structures labeled A, B, and C. 49. The inner membrane of the mitochondria is folded many times. What advantage does this folding provide?

7 50. At one time people believed that organisms could be formed spontaneously from nonliving matter. Evaluate this belief in light of the cell theory. 51. Between which cell types is the difference greater--plant and animal cells or prokaryotic and eukaryotic cells? Give reasons for your answer. 52. Why is it important that some proteins extend all the way through the bilayer of a plasma membrane?