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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. In skeletal and cardiac muscle tissue - a filament composed of bundles of myosin molecules. The myosin head groups attach to the thick filaments and pull the toward the center of the sarcomere during muscle contraction.






2. 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






3. (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.






4. The outer layer of smooth muscle in the wall of the digestive tract. When the longitudinal muscle contracts the tube shortens.






5. An asexual method of bacterial reproduction that serves only to increase the size of the population; ther is no introduciton of gnetic diversity. THe bacterium simply grows in size until it has doubled its cellular components - then it replicates its






6. Also called vasopressin - this hormone is produced in the hypothalamus and secreted by teh posterior pituitary gland. It tartes teh kidney tubules - increasing their permeability to water - adn thus increasing water retention by the body. Also raises






7. The burrowing of a blastocyst (a developing embryo) into the endometrium of the uterus - typically occuring about a week after fertilizaiton.






8. A triat determined by a gen on either the X or Y chromosomes (the sex chromosomes).






9. A peptide hormone produced and secreted by the Beta cells of the pancreas. Insulin targets cells in the body - especially the liver and muscle - and allows them to take glucose out of gthe blood (thus lowering blood glucose levels).






10. 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.






11. The primary muscle of inspiration. The diaphragm is stimulated to contract at regular intervals by the respiratory center in the medulla oblongata (via the phrenic nerve). Although it is made of skeletal muscle (and can therefore be voluntary control






12. A cyclic version of adenosine monophosphate - where the phosphate is esterified to both the 5' and 3' carbons - forming a ring. Cyclic AMP is an important intracellular signaling moelcule - often called the 'second messenger.' It serves to activate c






13. A situation in which a heterozygot displays a blended version of the pheotypes associated with each allele - e.g. pure - breeding white - flowered plants crossed with pure - breeding red - flowered plants produces heterozygous offspring plants with p






14. A molecule composed of two monosaccharides. Common disaccharides include maltose - sucrose - and lactose.






15. An integral protein that selectively allows molecules across the plasma membrane. See also entries under 'ion channel' - 'voltage - gated channel' - and 'ligand - gated channel'.






16. The layer of granulosa cells taht surround an oocyte after is has been ovulated.






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






18. A gland that secretes a waxy product - found in the external ear canal.






19. Swelling of tissues - sometimes caused by inflammation letting into many white blood cells (decreasing oncotic pressure at the end of the capillaries & not letting as much water back into capillaries & staying in tissues).






20. An organism that makes its own - typically using CO2 as a carbon source.






21. General - non - specific protection to the body - including the skin (barrier) - gastric acid - phagocytes - lysozyme - and complement.






22. 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






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






24. All of the cell cycle except for mitosis. Interphase includes G1 - S phase - and G2.






25. Zygot - derived projections that extend into the endometrium of the uterus during pregnancy. Fetal capillaries grow into the placental villi - which are surrounded by a pool of maternal blood. THis facilitates nutrient and gas exchange between the mo






26. 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.






27. The folds of the inner membrane of a mitochondrion






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






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






30. Something that increases the rate of a chemical reaction by reducing the activation energy for that reaction. The free energy of reaction remains unchanged.






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






32. The flow of blood through a tissue; ischeia is when there is no blood flow - anoxia when there is no O2 available (ischemia is more dangerous b/c of waste build - up)






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






34. Unmyelinated neuron cell bodies and short unmyelinated axons.






35. A hormone released by teh G cells of the stomach in the presence of food. Gastrin promotes muscular activity of the stomach as well as secretion of hydrochloric acid - pepsinogen - and mucus.






36. 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.






37. The subdivision of the nervous system consisting of the brain and spinal cord.






38. An enzyme whose transcription can be stimulated by an abundance of its substrate (as opposed to repressible enzyme). Usually in catabolism.






39. 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.






40. The stoppage of bleeding; blood clotting.






41. The product of glycolysis; 2 pyruvic acid (pyruvate) molecules are produced from a single glucose molecule. In the absence of oxygen - pyruvic acid undergoes fermentation and is reduced to either lactic acid or ethanol; in the presence of oxygen - py






42. Major Histocompatability complex - a set of proteins found on the plasma membranes of cells that help display antigen to T cells. MHC I is found on all cells and displays bits of proteins from within the cell; this allows T cells to monitor cell cont






43. The enzymes that catalyzes the phosphorylation of glucose to form glucose -6- phosphate in the first step of glycolysis. This is one of the ain regulatory steps of this pathway. Hexokinase is feedback - inhibited by glucose -6- P.






44. A concentrated region of white blood cells found along the vessels of the lympatic system.






45. An energy storage molecule used by muscle tissue. The phosphate from creatine phosphate can be removed and attached to an ADP to generate ATP quickly.






46. Also called DNA pol - this is the enzyme that replicates DNA. Eukaryotes have a single version of the enzyme - simply called DNA pol (not need to know much detail); prokaryotes have three versions - called DNA pol I - DNA pol II - and DNA pol III.






47. 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






48. A hormone secreted by the anterior pituitary that tarets the mammary glands stimulating them to produce breastmilk.






49. The membranes that line the surface of the lungs (visceral pleura) and the inside wall of the chest cavity (parietal pleura).






50. An alkaline - fructose - rich fluid produced by three different glands in the male reproductive tract and released during ejaculation. Semen is very nourishing for sperm.