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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 bacterium having a spiral shape (plural = spirochetes)






2. The connection of a mosin head group to an actin filament during muscle contraction (the sliding filament theory).






3. Small cavities in the bone or cartilage that hold individual bones or cartilage cells.






4. 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 -






5. The location on a chromosome where transcription begins.






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






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






8. 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.






9. A system of blood vessels where the blood passes from arteries to capillaries to veins - then through a second set of capillaries - and then through a final set of veins. THere are two portal systems in the body - the hepatic portal system and the hy






10. The specialization of cell types - especially during the embryonic and fetal development.






11. A group of nucleotides that does not specify a particular amino acid - but instead serves to notify the ribosome that the protein being translated is complete. The stop codons are UAA - UGA - and UAG. They are also known as nonsense codons.






12. Cells that make up exocrine galnds - adn that secrete their products into ducts. For example - in the pancreas - acinar cells secrete digestive enzyme; in the salivary glands - acinar cells secrete saliva.






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






14. The movement of a substance from the filtrate (in the renal tuble) bak into the bloodstream. Reabsorption reduces the amount of a substance in the urine.






15. A form of genetic recombination in bacteria in which plasmid and/or genomic DNA is transferred from one bacterium to the toher through a conjugation bridge.






16. A point mutation in which a pyrimidine is substitued for a purine - or vice versa.






17. Muscles located in between the ribs that play a role in ventilation.






18. 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






19. 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.






20. 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






21. Hardy crystals consisting of calcium and phosphate that form the bone matrix.






22. A hormone produced by the C- cells of the thyroid gland that decreases serum calcium levels. It targets teh bones (stimulates osteoblasts) - the kidneys (reduces calcium reabsorption) - and the small intestine (decreases calcium absorption).






23. A viral enzyme that makes a strand of RNA by reading a strand of RNa . All prokaryotic and eukaryotic RNa polymerases are DNa dependent; they make a strand of RNa by reading a strand of DNA.






24. A protein fiber with a unique triple - helix that gives it great strength. Tissues with a lot of collagen fibers are typically very strong - e.g. bone - tendons - ligaments - etc.






25. A large multinucleate cell - typically formed by the fusion of many smaller cells during development (e.g. a skeletal muscle cell) - or formed by nuclear division in the absence of cellular division.






26. The non - specific uptake of solid material by a cell accomplished by englufing the particle with plasma membrane and drawing it into the cell.






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






28. Lacking a blood supply; cartialge is an example of this






29. A blood clot that forms in an unbrokened blood vessel. Thrombi are dangerous they can break free and begin travelin in the bloodstream (become an embolus). Emboli ultimately become stuck in a small vessel and prevent adequate blood delivery to tissue






30. The fourth of meiosis I. Telophase I is identical to mitotic telophase - except that the number of chromosoms is now reduced by half. After this phase the cell is considered to be haploid. Note however - that the chromosomes are still replicated - an






31. 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.






32. 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






33. The first branches of the trachea. There are two primary bronchi - one for each lung.






34. The perio dof tim ein a woman's life when ovulation and menstruation cease. Menopause typically begins in the late 40s.






35. An organ that develops during pregnacy - derived in part from the mother and in part from the zygote. The placenta is the site of exchange of nutrients and gases between the mother's blood and the fetus' blood. The placenta is formed during the first






36. 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.






37. 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.






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






39. Oil - forming glands found all over the body - especially on the face and neck. The product (sebum) is released to the skin surface through hair follicles.






40. The plasma membrane of a muscle cell.






41. Active transport that releies on an established concentration gradient - typically set up by a primary active transporter. Secondary active transport relies on ATP indirectly.






42. One of the contractie proteins in muscle tissue. In skeletal and cardiac muscles - myosin forms the thick filaments. Myosin has intrinsic ATPase activity and can exist in two conformation - either high energy or low energy.






43. The enzymatic process of reading a strand of DNA to produce a complemenetary strand of RNA






44. 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.






45. A prokaryotic enzyme used to twist teh single circular chromosome of prokaryotes upon itself to form supercois. Supercoiling helps to compact prokaryotic DNa and make it sturdier.






46. Integration by a postsynaptic neuron of inputs (EPSPs and IPSPs) from multiple sources.






47. (singular alveolus.) Tiny sacs - with walls only a single cell layer thick found at the end of the respiratory bronchiole tree. Alveoli are the site of gas exchange in the respiratory system.






48. A hair - like structure on teh cell surface composed of microtubules ina '9+2' arrangement (nine pairs of microtubles surrounding 2 single microtubules in the center). Teh microtubules are conneted with a contractile protien called dynein. Cilia beat






49. Chemoreceptors on the tongue that respond to chemicals in a food.






50. One of the main pancreatic proteases; it is activated (from chymotrypsinogen) by trypsin.