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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. 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






2. The main protease secreted by the pancreas; trypsin is activated (from trypsinogen) by enterokinase - and subsequently activates other pancreatic enzymes.






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






4. 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.






5. 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.






6. A receptor that responds to changes in body position - such as stretch on a tendon - or contraction of a muscle. These receptor allow us to be consciously aware of the position of our body parts.






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






8. Peptidyl - tRNA site; the stie on a ribosome where the growing peptide (attached to a tRNA) is found during translation.






9. The space between the inner and outer cell membranes in Gram - negative bactera. The peptidoglycan cell wall is found in the periplasmic space - and this space sometimes contains enzymes to degrade antibiotics.






10. The secon phase of mitosis. During metaphase chromosomes align at the center of the ell (the metaphase plate).






11. A situation in which a heterozygote displays the phenotype associated with each of the alleles - e.g. - human blood type AB.






12. Receptors in the carotid arteries and the aorta that monitor blood pH to help regulate ventilation rate.






13. 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).






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






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






16. A sensory receptor that responds to mechanical disturbances - such as shape changes (being squashed - bent - pulled - etc.). Mechanoreceptors include touch receptors in the skin - hair cells - in the ear - muscle spindles - and others.






17. The reduced from (carries electrons) of FAD (flavin adenine dinucleotide). this is the other main electron carrier in cellular respiration (NADH is the most common).






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






19. An organism that requires oxygen to survive (aerobic metabolism only).






20. The portion of an integral membrane protein that passes through the lipid bilayer.






21. A lubricating - nourishing fluid found in joint capsules.






22. The movement of the membrane potential of a cell away from rest potential in a more negative direction.






23. 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.






24. 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.






25. A subphase of male orgasm - a reflex reaction triggered by the presence of semen in the urethra. Ejaculation is a series of rhythmic contractions of muscles near teh base of teh penis that increase pressure in the urethra - forcing the semen out.






26. Very small air tubes int eh respiratory system (diameter 0.5 - 1.0 mm). The walls of the bronchioles are made of smooth muscle (thus involunatry) to help regulate air flow.






27. A hormone secreted by the samll intestine (duodenum) in response to the presence of fats. It promotes release of bile from the gallbladder and pancreatic juice from the pancreas - and reduces stomach motility.






28. Also known as the Bundle of His - this is the first portion of the cardiac conduction system - after the AV node.






29. The small artery that carries blood toward the capillaries of the glomerulus.






30. A hormone released from the hypothalamus that triggers the anterior pituitary to secrete FSH and LH.






31. One of two large chambers in the heart. The ventricles receive blood from the atria and pump it out of the lungs of the heart. The right ventricle has thing walls and pumps deoxygenated blood to the lungs through the pulmonary artery. The left ventri






32. An immune organ located near the heart. THe thymus is the site of T cell maturation and is larger in children and adolescents.






33. One of the three primary (embryonic) germ layers formed during gastrulation. Endoderm ultimately forms internal structures - such as the inner lining of the GI tract and glandular organs.






34. 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






35. Identical copies of a chromosome - produced during DNA replication and held together at the centromere Sister chromatids are separated during anaphase of mitosis.






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






37. A peptide hormone produced and secreted by the alpha cells - of the pancreas. It tartes primarily the liver - stimulating the breakdown of glycogen - thus increasing blood gluocse level.s






38. A type of syanpse in which the cells are connected by gap junctions - allowing ions (and therefore an action potential) to spread easily from cell to cell - usually in smooth and cardiac muscle. - compared to chemical synapse.






39. HCO3-. THis ion results from the dissociation of carbonic acid - together wiht carbonic acid forms the the major blood buffer system. Bicarbonate is also secreted by teh pancreas to neutralize stomach acid in the intestines.






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






41. Small convoluted tubules in the testes where spermatogenesis takes place.






42. A solid clump of cells resulting from cleavage in the early embryo. Because there is very little growth of these cells during cleavage - the morula is ony about as large as the original zygote.






43. Steroid hormones secreted from the adrenal cortex. The two major classes are teh mineralocorticoids and glucocorticoids. Aldosterone is the principal mineralocorticoid - and cortisol is the principal glucorcorticoid.






44. 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






45. An irritation of a tissue caused by infection or injury. Inflammation is characterized by four cardinal symptoms; redness (rubor) - swelling (tumor) - heat (calor) - and pain (dolor).






46. Specialized lymphatic capillaries in the intestines that take up lipids as well as lymph.






47. The pressure measured in the arteries during contraction of the ventricles (during systole).






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






49. Arise in blood pH due to hyperventilation (excessive breathing) and a resulting decrease in CO2.






50. The inner layer of smooth muscle in the wall of the digestive tract. When the circular muscle contracts - the tube diameter is reduced. Certain areas of the circular muscle are thickened to act as valves (sphincters).