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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. The layer of ciliated - mucus - covered cells in the respiratory tract.The cilia continually beat - sweeping contaminated mucus upward toward the pharynx.






2. The plasma membrane of a muscle cell.






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






4. A nucleotide sequence on DNA that contians three elemtns: a coding sequence for one or more enzymes - *a coding sequence for a regulatory protein - and upstream regulatory sequences where the regulatory proteins can bind. An example is the lac operon






5. A type of cell division (in diploid cells) that reduces the number of chromosomes by half. Meiosis usualy produces haploid gametes in organisms that undergo sexual reproduction. It consists of a single interphase (G1 - S - and G2) followed by two set






6. The volume of blood pumped out the heart in a single contraction.






7. The first step in viral infection. Attachemen of a virus to its host is very specific and is also known as adsorption.






8. A red blood cell; they are filled with hemoglobin - and teh function of the erythrocytes is to carry oxygen in the blood.






9. A globular protein that ssociated with tropomyosin as part of the thin filament of the sarcomere. Troponin binds Ca2+ - which causes the conformaiton change in tropomyosin required to expose the myosin - binding sites on actin and initiate muscle con






10. 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






11. A hormone produced and secreted by teh adrenal medulla that prolongs and increases teh effects of the sympathetic nervous system.






12. 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.






13. A point mutation in which a codon that specifies an amino acid is mutated into a new codon that specifies the same amion acid.






14. The portion of the hindbrain that controls respiratory and blood pressure - and specialized digestive and respiratory functions such as vomiting - sneezing - and coughing.






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






16. The failure of homologous chromosomes or sister chromatids to separate properly during cell division. This could ocur during anaphase I of meiosis (homologous chromosomes) [--> leaving 2 gametes w/ 2 copies and 2 gametes w/ no copies of chromosome] -






17. Mal sex hormones. Testosteron is the primary androgen.






18. In the autonomic division of the PNS - a neuron that has its cell body located in the autonomic ganglion (where a preganglionic neuron synapses with it) and whose axon synapses with the target axon.






19. 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






20. A type of lipoprotein; the form in which absorbed fats from the intestines are transported to the circulatory system.






21. The membrane surrounding the DNA in eukaryotic cells made of two lipid bilayers.






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






23. The largest artery in teh body; the aorta carries oxygenated blood away from the left ventricle of the heart.






24. The first phase of the uterine (endometrial) cycle - during which the endometrium from the previous cycle is shed off. Estrogen and progesterone levels are low during this time period. Menstruation typically lasts from day 1 to day 5 of the cycle.






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






26. The 3D site of an enzyme where substrates (reactants) bind and a chemical reaction is facilitated.






27. 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






28. A group of blood proteins that bind non - specifically to the surface proteins of foreign cells (such as bacteria) - ultimately leading to the destruction of the foreign cell - part of the innate immunity.






29. A long projection on a bacterial surface involved in an attachment - e.g. - the sex pilus attaches F+ and F- bacteria during conjugation.






30. A sensory receptor that responds to hcanges in pressure; for example - there are baroreceptors in the carotid arteries and the aortic ach that monitor blood pressure.






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






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






33. A globular protein found in muscle tissue that has the ability to bind oxygen. Myoglobin helps to store oxygen in the muscle for use in aerobic respiration (it does not move - just stays there). Muscles that participate in endurance activities (inclu






34. An RNA polymerase that creates a primer (made of RNA) initiate DNa replication. DNA pol binds to the primer and elongates it.






35. A bundle of skeletal muscle cells. Fascicles group together to form skeletal muscles.






36. Also called simply - 'islet cells' these are the endocrine cells of the pancreas. Different cell types wihtin the inslets secrete insulin - glucagon - and somatostatin






37. The specialized cells of the heart that spontaneously initiate action potentials and transmit them to the cardiac muscle cells. The cells of the conduction system are essentially cardiac muscle cells - but lack the contractile fibers of the muscle ce






38. A type of lymphocyte that can recognize (bind to) an antigen adn secrete an antibody specific for that antigen. When activated by binding an antigen - B cells mature into plasma cells (that secreted antibody) and memory cells (that patrol the body fo






39. A structure composed of a ribose molecule linked to one of the aromatic bases. In a deoxynucleoside - the ribose is replaced with deoxyribose.






40. A contractile protein. In skeletal and cardiac muscle - actin polymerizes (along with other proteins) to form the thin filaments. Actin is involved in many contractile activities - such as cyotkinesis - pseudopod formation - and muscle contraction.






41. 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.






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






43. A mutation caused by an insertion or deletion of base pairs in a gene sequence in DNA such that the reading frame of the gene (and thus teh amino acid sequence of the protein) is altered.






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






45. A type of white blood cell; leukocytes are either B or T cells and are involved in disease defense.






46. 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






47. One of the four aromatic bases found in DNA and RNA. Cytosine is a pyrimidine; it pairs with guanine.






48. The first part of the large intestine.






49. Toward the 3' end of an RNA transcript (the 3' end of the DNA coding strand). Stop codons and (in eukaryotes) the pol - A tail are found 'downstream.'






50. A receptor that responds to light