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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. Paired glands near the posterior side of the vaginal that secrete an alkaline mucus upon sexual arousal. The mucus helps to reduce the acidity of the vagina (which could be harmful to sperm) and lubricates the vagina to facilitate penetration.






2. An irritation of a tissue caused by infection or injury. Inflammation is characterized by four cardinal symptoms; redness (rubor) - swelling (tumor) - heat (calor) - and pain (dolor).






3. An insulating layer of membranes wrapped around the axons of almost all neurons in the body. Myelin is essentially the plasma membranes of specialized cells; Schwann cells in the peripheral nervous system - and oligodendrocytes in the central nervous






4. A relatively direct connection between a sensory neuron and a motor neuron that allows an extremely rapid response to a stimulus - often without conscious brain involvement.






5. (1) The integration of input (EPSPs and IPSPs) from many presynaptic neruons by a single postsynaptic neuron - either temporaly or spatially. Summation of al input can either stimulate the postsynaptic neuron and possibly lead to an action potential






6. A rapid from of action potential conduction along the axon of a neuron in which the action potential appears to jump from nodde of Ranvier to node of Ranvier.






7. The opening to the uterus The ervix is typically plugged with a sticky acidic mucus during non - fertile times (to form a barrier against the entry of pathogens) - however during ovulation the mucus becomes more watery and alkaline to facilitate sper






8. The flow of blood from the heart - through the body (not including the lungs) - and back to the heart.






9. Fat cell






10. A sequence of amino acids (usually basic) that directs a protein to the nuclear envelope - where it is imported by a specific transport mechanism.






11. Partially digested - semiliquid food mixed with digestive enzymes and acids in the stomach.






12. The blood vessel that carries deoxygenated from the right ventricle of the heart to the lungs.






13. Multiple sites of replication found on large - linear eukaryotic linear eukaryotie chromosomes.






14. DNA that is loosely packed around histones. This DNA is more accessible to enzymes and the genes in euchromatin can be activated if needed.






15. A structure near the middle of eukaryotic chromosomes to which the fibers of the mitotic spindle attach during cell division.






16. The process of reading a strand of mRNA to synthesize protein. Protein translation takes place on a ribosome.






17. A sensory receptor that responds to specific chemicals. Some examples are gustatory (taste) receptors - olfactory (smell) receptors - and central chemoreceptors (responds to pH changes in teh cerebrospinal fluid).






18. A receptor that responds to light






19. Also called thryoid hormone - thyroxine is produced and secreted by follicle cells in the thyroid gland. it targets all cells in the body and increases overall body metabolism.






20. A protein hormone secreted by sustenacular cells of the testes that acts to inhibit the release of FSH and LH from the anterior pituitary.






21. The step in the sliding filament theory during which yosin undergoes a conformaitonal change to its low energy state - in the process dragging the thin filaments (and the attached Z lines) toward the center fo the sarcomere. NOte that power stroke re






22. A form of evolution in which different organisms are placed into the same environment and exposed to teh same selection pressures. This causes the organisms to evolve along similar lines. As a result - they may share functional - but not structural s






23. An electrical potential established across the plasma membrane of all cells by the Na+/K+ ATPase and the K+ leak channels. In most cells - the resting membrane potential is approximately -70 mV with respect to the outside of the cell.






24. A life cycle of animal viruses in which the mature viral particles bud from the host cell - acquiring an envelope (a coating of lipid bilayer) in the process.






25. The division of the periperal nervsous system that innervates and cotnrols the visceral organs (everything but the skeletal muscles). It is also knowns as the involuntary nervous system and an be subdivided into the sympathetic and parasympathetic di






26. A lipid bilayer that surrounds the capsid of an animal virus. the envelope is acquired as teh virus buds out through the plasma membrane of its host cell. Not all annimal viruses possess and envelope.






27. The rapid mitotic division of a zygot that being within 24-36 hours after fertilization






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






29. A layer of cells surroudning the granulosa cells of the follicles in an ovary. Thecal cells help produce the estrogen secreted from the follicle during the first phase of the ovarian cycle.






30. Amino - acyl tRNA site; the site on a ribosome where a new amino acid is added to a growing peptide.






31. A membrane lipid consisting of a glycerol molecule esteried to two fatty acid chains and a sugar molecule.






32. Diploid cells resultinf rom the activation of a spermatogoium; primary spermatocytes are ready to enter meiosis I. remember: cyte means ready to undergo meiosis.






33. The band of the sarcomere that extends the full length of the thick filament. The A band includes regions of thick and thin filament overlap - as well as a region of thick filament only. A bands alternate with I bands to give skeletal and cardiac mus






34. A rigid structure at the top of the trachea (so it is part of trachea - I assume) made completely out of cartilage. The larynx has three main functions: (1) its rigidness ensures that the trachea is held open (provides an open airway). (2) the epiglo






35. The 'blind spot' of the eye - this is where the axons of the ganglion cells exist the retinal to form the optic nerve. There are no photoreceptors in the optic disk.






36. The region of teh brain that coordinates and smooth skeletal muscle activity.






37. Transfer RNA; the type of RNA that carries an amino acid from the cytoplasm to the ribosome for incorporation into a growing protein.






38. A pair of similar chromosomes that have the same genes in the same order - but may have different versions (alleles) of those genes. One of the pair of chromosomes came from Mom in an ovum - and the other came from Dad in a sperm. Humans have 23 pair






39. A form of symbiosis in Which both organisms involved benefit from the association.






40. The membrane that separates the middle ear from the inner ear.






41. A period of time following an action potential during which no additional action potential can be evoked regardless of the level of stimulation. (usually because Na+ channel closed whle K+ efflux)






42. A tropic hormone produced by the anterior pituitary gland that targets the gonads. In females - FSH stimulates the ovaries to develop follicles (oogenesis) and secrete estrogen; in males - FSH stimulates spermatogenesis.






43. The exchange of DNA between paired homologus chromosomes (tetrads) during prophase I of meiosis.






44. The structure in the cochlea of the inner ear made up of the basilar membrane - the auditory hair cells - and the tectorial membrane. The Organ of Corti is the site where auditory sensation is detected and transduced to action potentials.






45. A thin - watery fluid found in teh anterior segment of the eye (between the lens and the cornea). THe aqueous humor is constantly produced and drained - adn helps to bring nutrients to the lesn and corena - as well as to remove metabolic wastes






46. A mechanism for increasing tension (contractile length) in a muscle by activating more motor units.






47. An activated B cell that is secreting antibody.






48. An immune reaction directed against normal (necessary ) cells.Fo example - diabets melitus (typeI) is an autoimmun reaction directed against teh beta cells of the pancrease (destorying them and preventing insulin secretion) and aginst insulin itself.






49. The fourth and final phase of meiosis II. Telophase II is identical to mitotic telophase - except that the number of chromosomes was reduced by half during meiosis. I.






50. The primary membrane lipid. Phospholipids consist of a glycerol molecule esterified to two fatty acid chains and a phosphate molecule. Additional - highly hyrohpilic groups are attached to the phosphate - making this molecule extremely amphipathic.