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MCAT Prep Biology

Subjects : mcat, science
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. A protein found in the plasma membrane of all cells in the body that uses the energy of an ATP (hydrolyzes ATP) to move three Na+ ions out of the cell and two K+ ions into the cell - thus establishing concentrations gradients for these ions across th






2. The central structure of the diencephalon of the brain. the thalamus acts as a relay station and major integrating area for sensory impulses.






3. The phase of the cell cycle during which the genome is replicated.






4. The ends of a saromere.






5. A cell that produces bone.






6. An RNA polymerase that creates a primer (made of RNA) initiate DNa replication. DNA pol binds to the primer and elongates it.






7. The primary muscle of inspiration. The diaphragm is stimulated to contract at regular intervals by the respiratory center in the medulla oblongata (via the phrenic nerve). Although it is made of skeletal muscle (and can therefore be voluntary control






8. The movement of teh membrane potential of a cell away from rest potential in a more positive direction.






9. The largest bundle of white matter (axons) connecting th two cerebral hemispheres.






10. A type of lipoprotein; the form in which absorbed fats from the intestines are transported to the circulatory system.






11. The contribution of an individual gas to the total ppressure of a mixture of gases. Partial pressures are used to describe the amounts of the various gases carried in the bloodstream.






12. A carrier protein that transports two molecules across the plasma membrane in the same direction. For example - the Na+- glucose cotransporter in intestinal cells is a symporter.






13. The flow of blood from the heart - through the lungs - and back to the heart.






14. One of two large chambers in the heart. The ventricles receive blood from the atria and pump it out of the lungs of the heart. The right ventricle has thing walls and pumps deoxygenated blood to the lungs through the pulmonary artery. The left ventri






15. In the autonomic divison of the PNS - a neuron that has its cell body located in the CNS - and whose axon extends into the PNS to synapse with a second neuron at an autonoic ganglion. (The second neuron's axon synapses with the target axon)






16. A function the reproductive system (conrolled by the sympathetic nervous system) that returns the body to its normal resting state after sexual arousal and orgasm.






17. The mechanism of contraction in skeletal and cardiac muscl cells. It is a series of four repeated steps: (1) myosin binds actin - (2) myosin pull actin toward the center of the sarcomere (3) myosin releases actin - and (4) myosin resets to its high -






18. The curled structure in the inner ear that contains the membranes and hair cells that transduce sound waves into action potentials.






19. An X- linked recessive disorder in Which blood fails to clot properly - leading to excessive bleeding if injured.






20. The portion of the nephron where water reabsorption is regulated via antidiuretic hormone (ADH). Several nephrons empty into each collecting duct - and this is the final region through which urine must passon its way to the ureter.






21. An organism that has only a single copy of its genome in each of its cells. Haploid organisms possess no homolous chromosomes.






22. The tendency of certain factors to stablize the hemoglobin in the tense conformation - thus reducing its affinity for oxygen and enhancing the relase of oxygen to the tissues. The factors include increased PCO2 - increase temperature - increased bisp






23. The division of the peripheral nervous system that innervates and controls the skeletal muscles; also known as the voluntary nervous system.






24. The main protease secreted by the pancreas; trypsin is activated (from trypsinogen) by enterokinase - and subsequently activates other pancreatic enzymes.






25. One of two large vessels (superior and inferior) that return deoxygenated blood to the right atrium of the heart.






26. The majority of the cells surrouding an oocyte in a follicle. Granulosa cells secrete estrogen during the follicular phase of the ovarian cycle (before ovulation).






27. The process by which neighboring cells can influence the determination (and subsequent differentiation) of a cell.






28. A small cell with extremely little cytoplasm that results from the unequal cytoplasmic divsion of the primary (produces the first polar body) and the secondary (produces the second polary body) oocytes during meiosis (oogenesis). The polar bodies deg






29. A digestive accessory organ near the liver. The gallbladder stores and concentrates bile produced by the liver - and is stimulated to contrat by cholecystokin (CCK).






30. Movement of a hydrophilic molecuel across the plasma membrane of a cell - down its concentration gradient - through a channel - pore - or carrier molecule in the membrane. Because the hydrophilic nature of the molecule - it requires a special path th






31. A cytoplasmic protein that recognizes the signal sequences of proteins destined to be translated at the rough ER. It binds first to the ribosome translating the protein with the signal sequence then to an SRP receptor on the rough ER>






32. A region within the nucleus where rRNA is transribed and ribosomes are partially assembled.






33. Aromatic bases found in DNa and RNA that have a single - ring structure. They include cytosine - thymine - and uracil.






34. A large - non - sepcific - phagocytic cell of the immune syste. Macrophages frequently leave the bloodstream to crawl around in the tissues and perform 'clean up' duties - such as ingesting dead cells or cellular debris at an injury site - or pathoge






35. A tissue in which the cytoplasms of the cells are connected by gap junctions - allowing the cells to function as a unit. Cardiac and smooth muscle tissues are examples of functional synctiums.






36. Heterogeneous nuclear RNA; the primary transcript made in eukaryotes before splicing.






37. The secretion of a cellular product to the extracellular medium through a secretory vesicle.






38. The inside of the a hollow organ (e.g. - the somach - intestines - bladder - etc.) or a tube (e.g. - blood vessels - ureters - etc.)






39. A dense - hard type of bone constructed from osteons (at the microscopic level). Compact bone forms the diaphysis of the the long bones - and the outer shell of the epiphyses and all other bones.






40. The first phase of meiosis I. During prophase I the replicated chromosomes condense - homologous chromsomes pair up - crossing over occurs between homologous chromosomes - the spindle is formed - and the nuclear envelope breaks apart into vesicles. P






41. All the genetic information in an organism; all of an organism's chromosomes.






42. Enzymes that degrade various macromolecules and that require an acidic pH to function properly. Acid hydrolases are found within the lysosomes of cells.






43. An organism that utilizes light as its primary energy source.






44. A person with blood type AB+. Because this person's red blood cells possess all of the typical blood surface proteins - they will not display an immune reaction if transfused with any of the other blood types.






45. A genotype in which two identical alleles are possessed for a given gene. The allelles can both be dominant (homozygous dominant) or both be recessive (homozygous recessive)






46. A protein - digesting enzyme secreted by the chief cells of the gastric glands. Pepsin is secreted in its inactive form (pepsinogen) and is activated by gastric acid. It is unusual in that its pH optimum is around 1-2; most of these enzymes in the bo






47. The specific molecule that binds to a receptor.






48. A bacterium having a rod - like shaped (plural = bacilli).






49. Something that works together with another thing to augment the the second thing's activity. For example - a uscle that assists another muslce is said to be a syngergist. An enzyme that helps another enzyme is a synergist.






50. An **inorganic molecule that associates non - covalently with an enzyme and that is required for the proper functioning of the enzyme