Biology Midterm Test Review Answers

“Biology Midterm: Test Review ANSWERS” MidTerm Review: “Unit 1” 1. 2. 3. 4. What does the work of a scientist usually begin with? Observations and research What is a hypothesis? A proposed explanation based on both qualitative and quantitative evidenced A hypothesis should be proposed in a way that is… Testable Why do scientists publish details of important experiments? It's required as a part of science. They must have the process written out clearly and in detail so that any other scientist could follow the instructions and get the same results. Experiments must be able to be repeated, and then the conclusions of the experiments can be accepted as true in the science community 5. What is a theory? Well tested explanation that explains, unifies, and reinforces a broad range of observations. Has never been tested incorrect. 6. What is Biology? The study of living organisms (both structurally and behaviorally) and their environment 7. What does cell specialization in multicellular organisms allow them to do? Cell specialization allows cells to have different structures and functions in order to carry out specific roles in maintaining homeostasis 8. What is homeostasis? Maintaining internal equilibrium/ balance 9. The basic unit of length, volume and mass using the SI method of measurement is? IS (International System of measurement used in sciences) - units of measurement are metric: length(meters), volume (liters), mass (grams) 10. Identify the macromolecules from the food label. a. Lipids - Fat b. Carbohydrates c. Proteins 11. The first person to identify and see cork cells was? Robert Hooke 12. What are the principles of the Cell Theory (3 parts)? a. 1.)All living things are made of cells b. 2.) cells are the basic unit of life c. 3.) cells arise from preexisting cells 13. Prokaryotes lack? Membrane bound organelles 14. Eukaryotes usually contain what? A nucleus and membrane bound organelles 15. What is found in the nucleus? Genetic information is located in the nucleus (both states such as DNA and Chromosomes) 16. What do prokaryotic, eukaryotic, and virus cells all contain? Genetic information 17. What 3 organelles are found in plants cells and not in animal cells? Chloroplasts, Cell Walls, 18. What is the main function of the cell wall? Cell walls provide structural support for cells 19. What serves as the cell’s boundary from its environment? The cell membrane serves as the boundary that facilitates transport in and out of the cell 20. What is the most abundant compound found in most living things? Water, H20 21. List 3-5 proper safety procedures? a. Wear the proper attire when performing labs (clothing, close toed shoes, protective goggles) b. No eating or drinking in the lab c. Always follow lab instructions carefully d. Report all damaged equipment or lab accidents to the teacher immediately e. Never run, push, or horseplay in the lab area 22. What is the monomer of RNA? Nucleotides are the building blocks of nucleic acids (both DNA and RNA) 23. What is the monomer of proteins? . amino acids and the building blocks of proteins 24. What are enzymes and how do they work? What is it called when an enzyme breaks down? Enzymes are proteins that speed up chemical reactions by lowering the activation energy required for the reaction to take place. When an enzyme “breaks down”, it has been denatured, and no longer works. 25. What are the products of photosynthesis and respiration? Photosynthesis: glucose and 6 oxygen; Cellular respiration: 6 carbon dioxide, 6 water, and 36-38 ATP 26. What is needed for photosynthesis to take place and where does it take place? Cellular respiration? Photosynthesis: 6 carbon dioxide and 6 water + sunlight (Stroma). Cellular respiration: glucose and 6 oxygen (mitochondria) 27. What is hypotonic, hypertonic and isotonic? Be able to describe each. a. Hypotonic solution - more water is concentrated outside of the cell than inside of the cell so water more moves into the cell (cell swells) (More solutes inside) b. Hypertonic solution - less water is concentrated outside of the cell than inside of the cell so more water moves out of the cell (cell shrinks) (More solutes outside) c. Isotonic solution - the water concentration is equal inside and outside of the cell so water moves into and out of the cell in equal amounts. 28. What is osmosis? The movement of water down a concentration gradient (from high concentration to low concentration) across a semipermeable membrane. 29. What is active transport? Movement of molecules against a concentration gradient (from low concentration to high concentration) that requires energy. 30. What is the sequence of events in cellular respiration and where do they take place? a. 1st - glycolysis (cytoplasm) b. 2nd - Kreb’s Cycle (mitochondria) c. 3rd - Electron Transport Chain (mitochondria) 31. How many ATP molecules are made in cellular respiration? How many without oxygen? a. With oxygen - 36-38 (2 used in process) b. Without oxygen - 2 (net gain) 32. Cellular respiration releases energy by breaking down what? Glucose (high energy sugar molecules) 33. What are the reactants in the equation for cellular respiration? Glucose and 6 oxygen 34. What is fermentation and why does it occur? Fermentation is the process that breaks down products made during glycolysis in the absence of oxygen. It occurs to prevent build up of those products and to create minimal amounts of energy. 35. What are two types of fermentation called? What are the products of each? a. Lactic acid fermentation - makes lactic acid b. Alcoholic fermentation - makes alcohol 36. Cellular respiration is called aerobic because it requires? Oxygen 37. What are the parts of the cell membrane and each of their functions? a. Phospholipids - make up the membrane b. proteins - transport molecules across the membrane (channel and carrier proteins) c. cholesterol - stabilizes the membrane d. carbohydrates - cell signaling (cell recognition and communication) 38. Why does the size of a cell matter? Volume increases faster than surface area, so smaller cells can transport molecules across the cell membrane more efficiently than larger cells MidTerm Review: “Unit 2” 39. Discuss the volume to surface ratio of a cell. What is (are) the limiting factors of cell growth? What are the problems that occur as the cell grows? The volume of a cell increases faster than the surface area resulting in not enough material being able to move into and out of the cell. The limiting factor is surface area. The problems that occur are DNA overload and movement in and out of the cell. 40. Describe the general process of cell division. The process by which a cell divides into two daughter cells. 41. What are the two main stages of cell division? Interphase and M (mitotic) phase. 42. What are the phases of Interphase, and give a brief overview of each (generally what happens). Specifically, what is the end result of the S Phase otherwise known as DNA Replication? The end result of S Phase is the replication of chromosomes producing homologous pairs or two original strands. a. G1 Phase - The cell grows b. S Phase - DNA is replicated c. G2 Phase - Organelles multiply in preparation for M Phase. 43. What are the phases of Mitosis (in order). Draw and describe the events that occur in each. a. Prophase - the nucleus disappears, DNA Condenses, The chromatid pairs (sister chromatids) are joined by a centromere, The thread-like spindle fibers appear, The centrioles move toward the poles. b. Metaphase - The shortest stage of mitosis, Sister Chromatids attach to spindle fibers, Chromatid pairs line up along the equator (middle) of the cell, Why does this occur? - So that each new cell will receive one chromatid from the pair. c. Anaphase - The chromatid pairs separate and the separated chromosomes move in opposite directions, The spindle fibers contract and somehow pull them toward the poles. d. Telophase - The cell begins to separate, Two new nuclei begin to reappear, Chromosomes decondense to form chromatin, The spindle fibers disappear. e. Cytokinesis - Final separation into 2 new daughter cells, Cells are identical in the type and number of chromosomes it contains, Each cell has its own nucleus with identical DNA