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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. The white portion of teh tough outer layer of the eyeball






2. The portion of an integral membrane protein that passes through the lipid bilayer.






3. The small artery that carries blood away from the capillaries of the glomerulus.






4. The specific molecule that binds to a receptor.






5. A mutation caused by an insertion or deletion of base pairs in a gene sequence in DNA such that the reading frame of the gene (and thus teh amino acid sequence of the protein) is altered.






6. The first generation of offspring from a given genetic cross.






7. A bacterial enzyme that recognizes a specific DNA nucleotide sequence and that cuts the double helix at a specific site within the sequence.






8. Small fragments of DNa produced on the lagging strand during DNa replication - joined later by DNA ligase to form a complete strand.






9. A nucleotide sequence on DNA that contians three elemtns: a coding sequence for one or more enzymes - *a coding sequence for a regulatory protein - and upstream regulatory sequences where the regulatory proteins can bind. An example is the lac operon






10. A statistical rule stating that the probability of either of two indpendent (and mutually exclusive) events ocuring is the sum of their individual probabilities minus the probability of them both occuring together.






11. The period of time following an action potential when it is possible - but difficult - for the neuron to fire a second action potential due to the fact that membrane is further from theshold potential (hyperpolarized).






12. A systme of ductless glands taht secrete chemical messengers (into) the blood - has to be into the blood.






13. A viral life cycle in which the viral genome is incorporated into the host genome where it can remain dormant for an unspecified period of time. Upon activation - the viral genome is excised from the host genome and typically enters the lytic cycle.






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. A bacterium that cannon survive on minimal medium (glucose alone) because it lacks the ability to syntheisze a molecule it needs to live (typically an amino acid). Auxotrphs must ave the needed substance (the auxiliary trophic substance) added to the






16. A blood vessel that carries blood away from the heart chambers. Arteries have muscular walls to regulate blood flow and are typically high - pressure vessles.






17. The maintenance of relatively constant internal conditions (such as temperature - pressure - ion balance - pH - etc.) regardless of external conditions.






18. A pathway through a plasma membrane that restrics passage based only on the size of the molecules. Pore are made from porin proteins.






19. A four - carbon molecule that binds with the two - carbon acetyl unit of acetyl - CoA to form citric acid in the first step of the Krebs cycle.






20. The period of exponential growth of bacterial population.






21. The first (approximately 5%) of the small intestinte.






22. A kinase in smooth muscle cells activated by calmodulin the presence of Ca2+. As its name implies - this kinase phosphorylates myosin - activating it so that muscle contraction can occur.






23. Receptors in the carotid arteries and the aorta that monitor blood pH to help regulate ventilation rate.






24. One of the two small chambers in the heart that receive blood and pass it on to the ventricles. The right atrium receives deoxygenated blood from teh body through the superior and inferiro vena cavae - adn the left atrium receives oxygenated blood fr






25. 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.






26. Molecules made from monosaccharides that serve as the primary source of cellular energy -. Carbohydrates can also act as cell surface markers (good thing to remember).






27. A thick - transpartent coating rich in glycoproteins that surrounds an oocyte.






28. The 28 days of the menstrual cycle as they apply to events in the ovary. The ovarian cycle has three subphases: the follicular phase - ovulation - and the luteal phase.






29. The failure of homologous chromosomes or sister chromatids to separate properly during cell division. This could ocur during anaphase I of meiosis (homologous chromosomes) [--> leaving 2 gametes w/ 2 copies and 2 gametes w/ no copies of chromosome] -






30. A group of three nucleotides taht is specific for a particular amino acid - or that specifies 'stop translating'






31. The second phase of meiosis I. During metaphase I the paired homologous chromsomes (tetrads) align at the center of the cell (the metaphase plate).






32. A toxin that secreted by a bacterium into its surrounding medium that help the bacterium compete with other species. Some exotoxins cause serious disease in humans (botulism - tetanus - diptheria - toxic shock syndrome).






33. An organism that will use oxygen (aerobic metabolism) if it is available - and that can ferment (anaerobic metabolism) if it is not.






34. An amphipathic molecule secreted by cells in the alveoli (type 2 alveolar cells) tha reducs surface tension on the inside of the alveolar walls. This prevents the alveoli from collapsing upon exhale and sticking together - thus reducing the effort re






35. A substance secreted by embryonic testes that causes the regression of the Mullerian ducts.






36. A structure composed of two coils of DNA wrapped around an octet of histone proteins. The nucleosome is the primary form of packagin of eukaryotic DNA.






37. The blood vessels taht carry blood to and from cardiac muscle. The coronary arteries branch off teh aorta and carry oxygenated blood to the cardiac tissue. The coronary veins collect deoxygenated blood from teh cardiac tissue - merge to form teh coro






38. The function unit of the kidney. Each kidney has about a million nehprons; this is where blood filtration and subsequent modification of the filtrate occurs. The nephron empties into collecting ducts - which empty into the ureter.






39. The point during development at which a cell becomes committed to a particular fate (sensory - other - etc.). Note that the cell is not differentiated at this point; determination comes before differentiation. Determination can be due to cytoplasmic






40. Molecules made by connecting amino acids via peptide bonds. Proteins are synthesized (translated) by ribosomes - and function as enzymes - carriers - structrual fibers - cell surface receptors - channels - porters - hormones - etc.






41. A neuron that carries information (action potentials) away from the central nervous system; a motor neuron.






42. 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)






43. One of the four aromatic bases found in DNA and RNA; also a component of ATP - NADH - and FADH2. Adenine is apurine; it pairs with thymine (in DNA) and with uracil (in RNA)






44. The tube that carries urine from the bladder to the to outside of the body. In males it also carries semen and sperm during ejaculation.






45. The third phase of the ovarian cycle - during which a corpus luteum is formed from the remnants of the follicle that has ovulated its oocyte. The corpus luteum secretes progestrone and estrogen during this time period - which typically lasts from day






46. Large conglomerations of proteins - fats - and cholesterol that transport lipids in the bloodstream. (chylomicrons are a type of lipoprotein).






47. The movement of molecules through the plasma membrane against their concentration gradients. Active transport requires input of cellular energy - often in the form of ATP. An example is the Na+/K+ ATPase in the plasma membrane of all cells.






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






49. The sequence of nucleotides on a chromosome that activates RNA polymerase so that transcription can take place. The promoter is found upstream of the start site - the location where transcription actually takes place.






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