D. They Are Composed of a Mixture of Lipids and Nucleotides

Leader: Lauren Exam Four Review Course: Biol 212 Supplemental Instruction Instructor: Dr. Coffman/Powell-Coffman Iowa State University Date: 11/28/2017

1. The cell walls of bacteria, fungi, and plant cells and the extracellular matrix of animal cells are all external to the plasma membrane. Which of the following is a characteristic common to all of these extracellular structures? a. They must provide a rigid structure that maintains an appropriate ratio of cell surface area to volume. b. They must block water and small molecules to regulate the exchange of matter and energy with their environment. c. They are constructed of polymers that are synthesized in the cytoplasm and then transported out of the cell. d. They are composed of a mixture of lipids and nucleotides. e. They must permit information transfer between the cell's cytoplasm and the nucleus.

2. H. V. Wilson worked with sponges to gain some insight into exactly what was responsible for holding adjacent cells together. He exposed two species of differently pigmented sponges to a chemical that disrupted the cell—cell interaction (cell junctions), and the cells of the sponges dissociated. Wilson then mixed the cells of the two species and removed the chemical that caused the cells to dissociate. Wilson found that the sponges reassembled into two separate species. The cells from one species did not interact or form associations with the cells of the other species. How do you explain the results of Wilson's experiments? a. One cell functioned as the nucleus for each organism, thereby attracting only cells of the same pigment. b. The two species of sponge had different enzymes that functioned in the reassembly process. c. The molecules responsible for cell—cell adhesion (cell junctions) differed between the two species of sponge. d. The molecules responsible for cell—cell adhesion (cell junctions) were irreversibly destroyed during the experiment.

3. Pemphigus vulgaris is an autoimmune disorder in humans in which antibodies are produced against the cadherins of desmosomes. The blistering of the skin and mucous membranes characteristic of this disorder is probably a result of ______. a. a decrease in flexibility of the cell membrane b. a loss in cell to cell adhesion c. inadequate production of cytoskeletal proteins d. an inadequate number of G-protein receptors 4. In experiments where researchers suspect that a hormone may be responsible for a certain physiological effect, they may cut the neurons leading to the organ where the effect being studied occurs. What is the purpose of cutting these neurons? a. to impair the normal functions of the organ so that the hormonal effect can be more easily studied b. to make sure that the organ being affected cannot function unless the researchers stimulate it with an external electrical probe c. to make sure that the effect is not occurring through actions in the nervous system d. to numb the organ so that it can be probed without inducing pain in the lab animal

5. Put the steps of the process of signal transduction in the order they occur: 1. A conformational change in the signal receptor complex activates an enzyme. 2. Protein kinases are activated. 3. A signal molecule binds to a receptor. 4. Target proteins are phosphorylated. 5. Second messenger molecules are released. a. 3, 1, 5, 2, 4 b. 1, 2, 3, 4, 5 c. 3, 1, 2, 4, 5 d. 1, 2, 5, 3, 4

6. Blood sugar is regulated by two pancreatic hormones—insulin and glucagon. When blood sugar rises, insulin is released; it binds to receptors and, through signal transduction, results in an increase in glucose uptake by cells, which effectively lowers blood glucose levels. When blood sugar decreases, glucagon is released, binds to cell receptors, and causes glucose to be released into circulation, thereby increasing blood glucose levels. Diabetes mellitus is a disorder that results from excessively high levels of blood glucose. Type II diabetics have normal to elevated levels of insulin. What, then, might be causing their elevated blood glucose levels? a. overproduction of glucagon b. inadequate insulin production c. defective receptors d. defective second messenger

7. Acetylcholine is a neurotransmitter that binds to receptors on skeletal muscle cells. The receptor signal complex brings about a series of events that result in contraction of skeletal muscle. Venom from black widow spiders causes an explosive release of acetylcholine. What would that do to its victims? a. The victim's cell receptors would be able to bind regulatory hormones but at a rate greatly exceeding normal rates. b. The victim's muscles would be unable to contract. c. The victim's muscles would be unable to relax. d. The victim's cell receptors would no longer be able to bind regulatory hormones.

8. Which of the following is an example of negative feedback? a. When blood glucose concentration increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases. b. When a baby is nursing, suckling leads to the production of more milk and a subsequent increase in the secretion of prolactin, which in turn stimulates lactation. c. After a blood vessel is damaged, signals are released by the damaged tissues that activate platelets in the blood. These activated platelets release chemicals that activate more platelets. d. During birthing contractions, the hormone oxytocin is released and acts to stimulate further contractions.

9. What explains the ability of honeybees to use heat to kill invading hornets? a. Hornets prefer higher temperatures than honeybees. b. Honeybees are better adapted to high temperatures than hornets. c. Honeybees are more sensitive to high temperatures than hornets. d. Honeybees can use evaporative cooling to reduce their body temperature. e. Hornets are ectotherms but honeybees are endotherms.

10. In a healthy person, after a large meal, the production of _____ will increase. After fasting, the production of _____ will increase. a. glucagon; glucose b. glucagon; pepsinogen c. trypsin; trypsinogen d. insulin; glucagon

11. If there is a strong genetic link for type II diabetes mellitus in your family, how might you minimize your risk of developing the disorder? a. eat complex carbohydrates like starch instead of sweets b. take oral insulin daily c. monitor your blood glucose levels daily d. maintain a healthy weight, eat a balanced diet, and exercise 12. Analysis of a blood sample from a fasting individual who had not eaten for 24 hours would be expected to reveal high levels of ______. a. Glucose b. Insulin c. Gastrin d. Glucagon e. secretin 13. Shortly after ingesting a big plate of carbohydrate-rich pasta, you measure your blood's hormone levels. What results would you expect, compared to before the meal? a. high insulin, high glucagon b. low insulin, no change in glucagon c. low insulin, high glucagon d. high insulin, low glucagon e. low insulin, low glucagon 14. Hypoglycemia, or low levels of glucose in the blood of a healthy human, is "corrected" by a(n) _____. a. increase in the secretion of thyroid hormones b. increase in the secretion of insulin c. decrease in the secretion of both insulin and glucagon d. increase in the secretion of both insulin and glucagon e. increase in the secretion of glucagon 15. When the body's blood glucose level rises, the pancreas secretes insulin and, as a result, the blood glucose level declines. When the blood glucose level is low, the pancreas secretes glucagon and, as a result, the blood glucose level rises. Such regulation of the blood glucose level is the result of ______. a. positive feedback b. negative feedback c. catalytic feedback d. bioinformatic regulation e. Protein protein interactions 16. Which of the following statements about the DNA in one of your brain cells is true? a. Each gene lies immediately adjacent to an enhancer. b. Most of the DNA codes for protein. c. Many genes are grouped into operon-like clusters. d. It is the same as the DNA in one of your heart cells. e. All of the genes of the genome are likely to be transcribed.

17. A mutation that inactivated a gene required for apoptosis in the digits of developing mice would result in ______. a. development of wing structures, such as feathers b. additional digits in the mouse's limb c. a mouse that retains webbing between its digits d. an embryo with a malformed brain 18. Which one of the following processes in a developing embryo is a prerequisite for all of the other processes? a. Organogenesis b. germ layer formation c. Mitosis d. cell differentiation 19. During metamorphosis, a tadpoles tail is reduced in size by the process of _____. a. Meiosis b. oxidative phosphorylation c. Re-differentiation d. Regeneration e. apoptosis 20. You are interested in studying a receptor and decide to make a knockout mouse. However, you notice severe developmental defects that result in embryonic lethality in this receptor knockout. Which developmental process is most likely affected when you disrupt a receptor on the cell surface, disrupting its ability to receive a signal and initiate a transduction pathway? a. cell proliferation b. Cell cell interactions c. Apoptosis d. cell differentiation e. cell movement 21. Muscle cells differ from nerve cells mainly because they _____. a. have different chromosomes b. have unique ribosomes c. use different genetic codes d. contain different genes e. express different genes 22. Cell differentiation always involves ______. a. the selective loss of certain genes from the genome b. the production of tissue-specific proteins, such as muscle actin c. the cell's sensitivity to environmental cues, such as light or heat d. the transcription of the myoD gene e. the movement of cells 23. Which of the following is an example of post-transcriptional control of gene expression? a. the removal of introns and alternative splicing of exons b. gene amplification contributing to cancer c. the binding of transcription factors to a promoter d. the folding of DNA to form heterochromatin e. the addition of methyl groups to cytosine bases of DNA 24. Scientists have found that the lifetimes of mRNAs coding for pair-rule regulatory elements in Drosophila embryos may last only a few minutes. What does this suggest about the overall developmental plan of an animal body? a. Timing of pair-rule sequence determination is not as important as spatial signaling. b. The role of mRNAs is less important than the position of genes in chromosomes. c. Building an animal body requires a sequence of precisely timed steps. d. Homeotic genes have greater impact in forming an embryo than mRNA from pair-rule genes. 25. Which of the following likely has the most Hox genes? a. Jellyfish b. Dolphins c. Bees d. slugs 26. Your brother has just purchased a new plastic model airplane. He places all the parts on the table in approximately the positions in which they will be located when the model is complete. His actions are analogous to which process in development? a. pattern formation b. Differentiation c. Morphogenesis d. Determination e. induction 27. The bicoid gene product is normally localized to the anterior end of the embryo. If large amounts of the product were injected into the posterior end as well, which of the following would occur? a. The embryo would grow extra wings and legs. b. The embryo would develop normally. c. Anterior structures would form in both ends of the embryo. d. The embryo would grow to an unusually large size. e. The embryo would probably show no anterior development and die. 28. The correct sequence of events in the development of humans and other mammals is ______. a. gastrulation, organogenesis, formation of a blastula, and then cleavage b. gastrulation, formation of a blastula, cleavage, and then organogenesis c. cleavage, formation of a blastula, gastrulation, and then organogenesis d. cleavage, gastrulation, organogenesis, and then formation of a blastula 29. During gastrulation, ______. a. the blastula forms b. the neural tube forms c. three germ layers form d. somites form 30. Gastrulation is an important event in early embryonic development. Which of the following is NOT a result of gastrulation? a. movement and alignment of many embryonic cells b. the formation of a gastrula c. formation of three embryonic cell layers d. the formation of specialized adult tissues 31. Cells move to new positions as an embryo establishes its three germ-tissue layers during ______. a. Determination b. Cleavage c. Gastrulation d. Fertilization e. Induction 32. The outer-to-inner sequence of tissue layers in a post-gastrulation vertebrate embryo is ______. a. endoderm → ectoderm → mesoderm b. ectoderm → endoderm → mesoderm c. mesoderm → endoderm → ectoderm d. ectoderm → mesoderm → endoderm e. Endoderm → mesoderm → ectoderm 33. If gastrulation was blocked by an environmental toxin, then ______. a. fertilization would be blocked b. the blastopore would form the mouth c. embryonic germ layers would not form d. cleavage would not occur in the zygote e. the blastula would not be formed 34. The vertebrate ectoderm is the origin of the ______. a. Kidneys b. Liver c. Heart d. nervous system e. pancreas 35. Which of the following is a correct description of the fate of the germ layers? a. The ectoderm gives rise to the liver. b. The mesoderm gives rise to the lungs. c. The mesoderm gives rise to the skeletal system. d. The endoderm gives rise to the hair follicles. 36. From earliest to latest, the overall sequence of early development proceeds in which of the following sequences? a. gastrulation → blastulation → neurulation b. preformation → morphogenesis → neurulation c. cleavage → gastrulation → organogenesis d. gastrulation → organogenesis → cleavage e. ovulation → gastrulation → fertilization 37. The embryonic precursor to the human brain is the ______. a. Archenteron b. Notochord c. Mesoderm d. set of bilateral somites e. neural tube 38. Somites give rise to all of the following tissues EXCEPT ______. a. connective tissue b. bone tissue c. nervous tissue d. muscle tissue e. dermal skin tissue 39. What is meant by the term somite? See Section 47.4 ( page 995) . a. The endodermal lining of the stomach b. Rod-like mesoderm that provides longitudinal support to the growing embryo c. A tubular structure derived from ectoderm that runs the length of the animal d. A block of mesodermal tissue that gives rise to muscles, bone, and skin 40. Both root system and shoot system in plants are involved in shared functions as well as distinct functions. Which of the following defines a function common to both roots and shoots? a. Harvesting resources from the environment b. Photosynthesis c. Anchoring the plant d. Absorption of mineral nutrients 41. What is meant by phenotypic plasticity in roots and shoots? See Section 34.1 ( page 706) . a. The ability to modify form depending on environmental conditions b. The nature of cell walls, allowing cells to expand and shrink when necessary c. The amount of elongation growth in a growing season d. The ability to harvest resources from the environment 42. Which of these cell types are still alive with a functioning nucleus at maturity? See Section 34.2 ( page 714) . a. Tracheids b. Sclereids c. Vessel elements d. Parenchyma 43. The function of sieve-tube elements is to _____. See Section 34.2 ( page 714) . a. transport carbon dioxide into leaves b. transport water downward c. transport water upward d. transport sugars throughout the plant 44. Water transport is the primary function of which cell type? See Section 34.3 ( page 719) . a. Epidermal cells b. Parenchyma cells c. Tracheids d. Sieve tube elements 45. What does the cuticle do? a. reduces water loss b. stores nutrients c. forms thorns d. transports water and ions 46. What do stomata do? a. store wastes b. transport water and ions c. connect the cytoplasm of adjacent plant cells d. facilitate gas exchange 47. Plants from dry habitats would have a ___ cuticle and ____ stomata. a. Thick; few b. Thick; many c. Thin; few d. Thin; many 48. Plants from wet habitats would have a ___ cuticle and ____ stomata. a. Thick; few b. Thick; many c. Thin; few d. Thin; many 49. How do plants that are adapted to dry and salty soils tolerate the low water potential in the environment? See Section 35.1 ( page 729) . a. By keeping their stomata closed all the time b. By lowering the solute potential inside their cells c. By increasing transpiration d. By wilting during daytime 50. In which of the following conditions would transpiration be expected to be highest? a. A hot, dry, and windy day b. A cloudy humid day c. When stomata are closed d. When it is raining 51. The flow of xylem from root to leaf in a tall tree is principally due to ______. See Section 35.2 ( page 732) . a. root pressure, the buildup of pressure in a root due to its intake of water b. a decrease in water potential in the leaves due to evaporation c. an increase in solutes in the leaf d. an increase in water potential in the leaves due to evaporation 52. What is the force behind the process known as "transpiration" in plants? See Section 35.2 ( page 732) . a. Cohesion-tension b. Water is absorbed into the leaves through stomata. c. Carbon dioxide is absorbed through stomata. d. Water is absorbed into the roots through root hairs. 53. Some plants growing in arid climates have small leaves and thick waxy cuticles on the upper epidermis. This is an adaptation for _____. a. decreasing water breakdown in photosynthesis b. increasing transpiration c. decreasing water loss from leaves d. increasing water absorption 54. According to the pressure-flow hypothesis, which direction are sucrose and water flowing in the phloem when roots are sources and leaves are sinks? See Section 35.4 ( page 739) . a. Water and sucrose flow down the stem. b. Water flows down the stem, and sucrose flows up the stem. c. Water flows up the stem and sucrose flows down the stem. d. Water and sucrose flow up the stem. 55. Which of the following plant organs may act as a source for translocation of sugars inside a plant? See Section 35.4 ( page 739) . a. Mature leaves b. Young growing leaves c. Any non-green tissue d. Developing flowers 56. What makes a nutrient an essential nutrient to plants? See Section 36.1 ( page 749) . a. It is required for photosynthesis or respiration. b. It is needed in large quantities by all plants. c. It is required for normal growth and reproduction. d. It is part of photosynthetic structures. 57. What defines a micronutrient? See Section 36.1 ( page 749) . a. The effects are essential but are very small and hard to detect. b. It is needed in very minute quantities. c. It is a very small molecule or atom. d. It is needed only by microscopic organisms. 58. What is biological nitrogen fixation? See Section 36.4 ( page 759) . a. The conversion of nitrogen gas into ammonium ions inside root cells b. The conversion of nitrogen gas into ammonia, nitrate, or nitrite by microbes c. The absorption of nitrate ions by plant roots d. The exclusion of excess nitrate ions from plant roots 59. Legume plant roots are colonized by _____ to form root nodules. a. Epiphytes b. Ectomycorrhizae c. Rhizobia d. node factors 60. There are two types of cells in a container. Type A and type B. Type A cells adhere to type A cells and type B cells adhere to types B cells. If we add a third type, type C cells, how do you expect them to interact with the other cells? a. Type C will mix in with A and B b. Type C will cause A and B to separate c. Type C will adhere to A d. Type C will adhere to type C only