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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 percentage of individuals with a particular genotype that actually displays the phenotype associated with the genotype.






2. The ability of tissues to regulate their own blood flow in the absence of neural stiulation. THis is generally accomplished via metabolic wastes (such as CO2) that act as vasodilators.






3. A viral life cycle in which the host is turned into a 'virus factory' and ultimately lysed to release the new viral particles.






4. The valve that controls the release of urine from the bladder. It has an internal part made of smooth muscle (thus involuntary) and an external part made of skeletal muscle (thus voluntary).






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






6. The stoppage of bleeding; blood clotting.






7. A structure composed of a ring of nine microtube triplets - found in pairs in the MTOC (microtubule organizing center) of a cell. The centrioles duplicate during the cell division - and serve as the organizing center for the mitotic spindle.






8. A passageway leading from behind the nasal cavity to the trachea. The pharynx is divided into three regions - named for their location. The nasopharynx is behind the nasal cavity - the oropharynx is behind the oral cavity - and the laryngopharynx is






9. A green fluid made from cholesterol and secreted by teh liver. It is stored and concentrated in the gallbladder. Bile isn an amphipathic molecule that is secreted itno the small intestine when fats are present - adn serves to emulsify the fats for be






10. An enzyme that unwinds the double helix of DNA and separates the DNA strands in preparation for DNA replication.






11. An enzyme present in erythrocytes (as well as in other places) that catalyzes the conversion of CO2 and H2O into carbonic acid (H2CO3).






12. Photoreceptors in the retina of the eye that respond to dim light and provide us with black and white vision.






13. A tropic hormone produced by the anterior pituitary gland that targets the thyroid gland - stimulating it to produce and release thyroid hormone.






14. The prokaryotic ribosome - binding site on mRNA - found 10 nucleotides 5' to the start codon.






15. The outer layer of an organ - e.g. the renal cortex - the ovarian cortex - the adrenal cortex - etc.






16. A diploid cell that can undergo mitosis to form more spermatogonium - and can also be triggered to undergo meiosis to form sperm.






17. The three small bones found in the middle ear (the malleus - the incus - and the stapes) that help to amplify the vibrations from sound waves. The malleus is atached to the tympanic membrane and the stapes is attached to the oval window of the cochle






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






19. A flexible piece of cartilage in the larynx that flips downward to seal teh trachea during swallowing.






20. An ion channel specific for potassium found in the plasma membrane of all cells in the body. Leak channels are constitutively open and allow their specifi ion to move across the membrane according to its gadient. Potassium leak channels allow potassi






21. Bacteria that have a thick peptido glycan cell wall - and no outer membrane. They stain very darkly (purple) in Gram stain.






22. The folds of skin that enclose the vaginal and urethral openings of females.






23. The first phase of the ovarian cycle - during which a follicle (an oocyte and its surroudning cells) enlarges and matures. This phase is under the control of FSH from the anterior pituitary - and typically lasts from day 1 to day 14 of the menstrual






24. A function in the reproductive system - controlled by the parasympathetic nervous system - that includes erection (via dilation of erectile arteries) and lubrication.






25. The non - specific uptake of liquid particles into a cell by invagination of the plasma membrane and subsequent 'pinching off' a small bit of the extracellular fluid.






26. A virus with an RNA genome (e.g. HIV) that undergoes a lysogenic life cycle in a host with a double stranded DNA genome. In order to integrate its genome with the host cell genome - the virus must first reverse trasncribe its RNA genome to DNA.






27. The monomer of a carbohydrate. Monosaccharides have the general chemical formula CnH2nOn - and common monosaccharides include glucose - fructose - galactose - and ribose.






28. The nerve extending from the back of teh eyeball to teh brain that carries visual information. The ptic nerve is made up of the axons of the ganglion cells of the retina.






29. The uptake of material into a cell - usually by invagination. See also 'phagocytosis' - pinocytosis - and receptor - mediated endocytosis..






30. A non - protein - but organic - molecule (such as vitamin) that is covalently bound to an enzyme as part of the active site.






31. A junction between cells - consisting of a protein channel called a connexon on each of the two cells that connect to form a single channel between teh cytoplasms of both cells. Gap junctions allow small molecules to flow between teh cells - and are






32. MRna that codes for several different proteins by utliizing different reading frames - nested genets - etc. Polycistronic mRNa is a characteristic of prokaryotes.






33. The interior of a mitochondrion (the region bounded by the inner membrane). - The matrix is the site of action of pyruvate dehydroganse complex and the Krebs cycle.






34. A hormone secreted by the small intestine (duodenum) in response to the presence of food. It decreases the rate at which chyme leaves the stomach and enters the small intestine.






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






36. The phase of mitosis during which the cell physically splits into two daugter cells. Cytokinesis begins near the end of anaphase - and is completed during telophase.






37. A hormone released by the anterior pituitary that targets all cells in the body. Growth hormone stimulates whole body growth in children and adolescents - adn increases cell turnover rate in adults.






38. A nucleotide sequence in RNA that contains protein - coding information. Exons are typically separated by introns (intervening sequences) that are spliced out prior to translation.






39. The second most common of the five classes of leukocytes. Lymphocytes are involved in specific immunity and include two cell types - B- cells and T cells. B- cells produce and secrete antibodies and T- cells are invovled in cellular immunity.






40. The process of breaking down large molecules into smaller precursors - e.g. digesion of starch into glucose.






41. One of several vessels that carry oxygenated blood from the lungs to the left atrium of the heart.






42. A clump of gray matter (unmyelinated neuron cell bodies) found in the peripheral nervous system.






43. A point mutation in which a condon that specifies an amino acid is mutated into a stop (nonsense) codon.






44. Complementary DNA. DNA produced synthetically by reverse trascribing mRNA. Because of eukaryotic mRNA splicing - cDNA contains no inrons.






45. 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






46. The three glands in the male reproductive system that reproduce semen: the seminal vesicles - the prostate - and the






47. Also called falopian tubes - these tubes extend laterally from their side of the uterus and serve as a passageway for the ocyte to travel from the ovary to the uterus. This is also the normal site of fertilization. Severing of the uterine tubes (tuba






48. The modifaction of enzyme activity through interactino of molecules with specific sites on the enzyme other than the active site (called allosteric sites)






49. The theory that mitochondria and chloroplasts originated as independent unicellular organsims living in symbiosis with larger cells






50. Summation by a postsynaptic cell of input (EPSPs or IPSPs) from a single source over time.