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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 physiological catalyst. Enzymes are usually proteins - although some RNAs have catalytic activity.






2. The ball of capillaries at the beginning of the nephron where blood filtration takes place.






3. A hormone made of amino acids (in some cases just a single - modified amino acid). Peptide hormones are generally hydrophilic and cannot cross the plasma membranes of cells - thus receptor for peptide hormones must be found on the cell surface. An ex






4. The process of bulidng complex structures out of simpler precursors - e.g. synthesizing protiens from amino acids.






5. 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>






6. The darkly pigmented middle layer of the eyeball - found between teh sclera (outer layer) and the retina (inner layer).






7. The flexible membrane in teh chochlea that supports the organ of Corti (structure which contains the hearing receptors). The fibers of the basilar membrane are short and stiff near the oval windown and long and fleaxible near the apex of the cochlea.






8. A law of population genetics that states that the frequencies of alleles in a given gene pool do not change over time. There are five assumptions required for this law to hold true: there must be no mutation - there must be no migration - there must






9. Diploid cells resulting from the activation of anoogoium; primary oocytes are ready to enter meiosis I. remember: cyte means ready to undergo meiosi






10. Paired glands found on the posterior external wall of the bladder in males. Their secretions contain an alkaline mucus and fructose - among other things - and make up approximately 60% of the ejaculate volume.






11. A blood protein essential to blood clotting. The conversion of fibrinogen to its active form (fibrin) is among the final steps in clot formation - and is triggered by thrombin.






12. Small organelles that contain the hydrogen peroxide produced as a byproduct of lipid metabolism. Peroxisomes convert hydrogen peroxide to water and oxygen by way of the enzyme catalase.






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






14. A function of the reproductive system controlled by the sympathetic nervous system. In males - organs includes emission and ejaculation; in females it is mainly a series of rhythmic contraction of the pelvic floor muscles and the uterus.






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






16. A carrier protein that transports two molecules acrss the plasma membrane in opposite directions.






17. The newly forming daughter strand of DNA that is replicated in a discontinuous fashion - via Okazaki fragments that will ultimately be ligated together; the daugther strand that is replicated in the opposite direction that parallel DNA is unwinding






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






19. An enzyme whose transcription can be stopped by an abundance of its product (as opposed to inducible enzymes). Usually part of anabolism of product.






20. A wave of contraction that sweeps along a muscular tube - pushing substances along the tube (e.g. - food through the digestive tract - urine through the ureters - etc.)






21. The inner region of an organ - e.g. - the renal medulla - the ovarian medulla - and the adrenal medulla - etc.






22. A series of enzyme complexes found along the inner mitochondrial membrane. NADH and FADH2 are oxidized by tehse enzymes; the electrons are shuttled down the chain and are ultimately passed to oxygen and to produce water. The electron energy is used t






23. 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.






24. A network of membranes inside eukarytoic cells invovled in lipid synthesis (steroid in gonads) - detoxification (in liver cells) - and/or Ca2+ storage (muscle cells).






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






26. 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.






27. A contact point between the afferent arteriole of the glomerulus and the distal convoluted tubule of the nephron. It is involved in regulating blood pressure.






28. The ends of a saromere.






29. A large system of folded membranes within a eukaryotic cell that has ribosomes bound to it - giving a rough appearnce. These ribosomes synthesize proteins that will ultimately be secreted from the cell - incorporated into the plasma membrane - or tra






30. A hormone tha tcontrols the release of another hormone.






31. 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






32. A gland that secretes its product into a duct - which ultimately carries the product to the surface of the body or into a body cavity. Some examples of exocrine gland and their products are sweat glands (sweat) - gastric glands (acid - mucus - protea






33. 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.






34. The amount of energy required to produce the transition state of a chemical reaction. If the activation energy for a reaction is very high - the reaction occurs very slowly. Enzymes (and other catalysts) increase reaction rates by reducing activation






35. The volume of air remaining in the lungs after a maximal forced exhalation - typically about 1200 mL.






36. The normal configuration of double - stranded DNA in which the 5' end of oen strand is paired with the 3' end of the other






37. Very small tube or channel - such as is found between lacunae (connecting them together) in compact bone.






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






39. The primary female sex hormone. Estrogen stimulates the development of female secondary sex characteristics during puberty - maintains those characteristics during adulthood - stimulates the development of a new uterine lining after menstruation - an






40. The movement of a particle (the solute) in a solution from its region of high concentration to its region of low concentration ( or down it concentration gradient).






41. 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.






42. The primary enzyme in peroxisomes; catalse catalyzes the hydrolysis of hydrogen peroxide (H2O2) into water and oxygen.






43. One of the four aromatic bases found in RNA. Uracil is pyrimidine; it pairs with adnenine.






44. The cord that connects the embryo of a developing mammal to the placenta in the uterus of the mother. The umbilical cord contains fetal arteries (carry blood toward the placenta) and veins (carry blood away from the placenta). The umbilical vessels d






45. A hormone produced from vitamin D that acts in essentially the same manner as parathyroid hormone.






46. A haploid cell resulting from the first meiotic division of oogenesi (not that the cytoplasmic division in this case is unequal - producing one large cell with almost all of they cytoplasm - the secondary oocyte - and one smaller cell with virtually






47. A subset of a species consisting of members that mate and reproduce with one another.






48. Mendels' first law. The Law of Segregation states that the two alleles of a given gene will be separate from one another during gamete formation (meiosis).






49. A carrier protein that transports a single molecule across the plasma membrane.






50. A tropic hormone produced by the anterior pituitary gland that targets the gonads. In females LH triggers ovulation and the development of a corpus luteum during the menstrual cycle; in males - LH stimulates the production and release of testosteron.