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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. An enzyme inhibitor that competes with substrate for binding at the active site of teh enzyme. When the inhibitor is bound - no product can be made.






2. Also known as the neurohyophysis - the posterior pituitary is made of nervous tisssue and stores and secretes two hormones made by the hypothlamus; oxtytocin and ADH. The posterior pituitary is controlled by action potentials from the hypothalamus.






3. To remove oxygen - to add hydrogen - or to add electrons to a molecule.






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






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






6. The location on a chromosome where transcription begins.






7. A structure made of two protein subunits and rRNA; this is the site of protein synthessis (translation) in a cell. Prokaryotic ribosomes (also known as 70S ribosomes) are smaller than eukaryotic ribosome (80S ribosomes). The S value refers to the sed






8. The 'language' of a molecular biology that specifies which amino acid corresponds to which three - nucleotide group (codon).






9. 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






10. The relationship of muscle length to its ability to generate strong contractions. Maximum tension (contraction strength) is achieved at sarcomere lengths between 2.0 and 2.2 microns. Tension decreases outside of this range <-- remember.






11. The movement of air into the respiratory tract. Inspiration is an active process - requiring contraction of the diaphragm.






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






13. A protein hormone secreted by sustenacular cells of the testes that acts to inhibit the release of FSH and LH from the anterior pituitary.






14. The perio of time during which the ventricles of the heart are relaxed.






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






16. The osmotic pressure in the blood vessels due only to plasma proteins (primarily albumin) --> causes water to rush back into capillaries at end.






17. The tendency of certain factors to stablize the hemoglobin in the tense conformation - thus reducing its affinity for oxygen and enhancing the relase of oxygen to the tissues. The factors include increased PCO2 - increase temperature - increased bisp






18. The regino of the digestive tract where virtually al digestion and absorption occur. It is subdivided into three regions: the duodenum - the jejunum - and the ileum.






19. The physical characterisitcs resulting from the genotype. Phenotypes are usually described as dominant or recessive.






20. A small cell with extremely little cytoplasm that results from the unequal cytoplasmic divsion of the primary (produces the first polar body) and the secondary (produces the second polary body) oocytes during meiosis (oogenesis). The polar bodies deg






21. 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






22. The cytoskeleton filaments with the smallest diameter. Microfilaments are composed of the contractile protein actin. They are dynamic filaments - constantly beig made and broken down as needed - and are responsible for events such as pseudopod format






23. Excitatory postsynaptic potential; a slight depolarization of a postsynaptic cell - bringing the membrane potential of that cell closer to the threshold for an action potential.






24. The attachment of an amino acid to a tRNA (not that this a specific interaction). tRNa loading requires two high - energy phosphate bonds.






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






26. Muscles that help focus light on teh retin by controlling the curvature of the lens of the eye.






27. 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






28. The intracellular process triggered by the binding of a ligand to its receptor on the cell surface. Typically this activates seond messenger pathways.






29. 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






30. The portion of theforebrain that includes the thalamus and hypothalamus.






31. The movement of teh membrane potential of a cell away from rest potential in a more positive direction.






32. A cyoplasmic Ca2+- binding protein. Calmodulin is particularly important in smooth muscle cells - where binding of Ca2+ allows calmodulin to activate myosin light - chian kinase - the first step in smooth muscle cell contraction.






33. 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.






34. A smooth sustained muscle contraction - such as occurs in skeletal muscle when stimulation frequency is high enough (this is the normal type of contraction exhibited by skeletal muscle).






35. The environment in which or upon Which bacteria grow. It typically contains a sugar source and any other nutrients that bacteria may require. 'Minimal medium' contain nothing but glucose.






36. The maximal volume of air that the lungs can contain. Total lung capacity is the sum of the vital capacity and the residual volume - and is typically about 6000 mL (6L).






37. The 28 days of the menstrual cycle as they apply to the events in the uterus. The endometrial cycle is also known as the uterine cycle - and has the three subphases: menstruation - the proliferative phase - and the secretory phase.






38. The third stage of cellular respiration - in which acetyl - CoA is combined with oxaloacetate to form citric acid. The citric acid is then decarboxylated twice and isomerized to recreate oxaloacetate. In the process - 3 molecules of NADH - 1 molecule






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 pituitary gland.






41. The allele in a heterozygou genotype that is not expressed; the phenotype resulting from possession of two recessive alleles (homozygous recessive).






42. The liquid portion of blood; plasma contains water - ions - buffers - sugars - proteins - etc. Anything that dissolves in blood dissolves in the plasma portion.






43. The entropy (disorder) of the universe (or system) tends to increase.






44. 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






45. A diploid cell formed by the fusion of two gametes during sexual reproduction.






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






47. A blood pressure cuff






48. The division of the autonomic nervous system known as the 'resting and digesting' system. It causes a general decrease in body activities such as heart rate - respiratory rate - and blood pressure - and an increase in blood flow to the GI tract and d






49. A mechanism for increasing tension (contractile length) in a muscle by activating more motor units.






50. One of the two ends of long bone (pl: eiphyses). The epiphyses have an outer shell made of compact bone and inner core of spongy bone. The spongy bone is filled with red bone marrow - the stie of blood cell formation.