Test your basic knowledge |

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. 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.






2. A stack of membranes found near the rough ER in eukaryotic cells that is involved in the secretory pathway. The Golgi is involved in protein glycosylation (and other protein modification) and sorting and packagin proteins.






3. 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






4. A type of mutation in DNa where a single base is substituted for another.






5. 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






6. The period of human development beginning at 8 weeks of gestation and lasting until birth (38-42 weeks of gestation). During this stage the organs formed in the embryonic stage grow and mature. The developing baby is known as a fetus during this time






7. An incrase in the fragility of the membranes of sperm cells when exposed to the female reproductive tract. Capacitation is required sot aht the acrosomal enzymes can be relased to faciliate fertilization.






8. Unicellular exocrine glands found along the respiratory and digestive tracts taht secrete mucus.






9. The bond formed between the carboxyl group of one amino acid and the amino group of another.






10. A thick - transpartent coating rich in glycoproteins that surrounds an oocyte.






11. Summation by a postsynaptic cell of input (EPSPs or IPSPs) from a single source over time.






12. Cranial nerve pair X. The vagus nerves are very large mixed nerves (They carry both sensory input and motor input) that innervate virtually every visceral organ. They are especially important in transmitting parasympathetic input to the heart and dig






13. A membrane lipid consisting of a glycerol molecule esteried to two fatty acid chains and a sugar molecule.






14. A function the reproductive system (conrolled by the sympathetic nervous system) that returns the body to its normal resting state after sexual arousal and orgasm.






15. A situation in which the expression of one gene prevents expression of all allelic forms of another gene - e.g. - the gene for male pattern baldness is epistatic to the hair color gene.






16. Proteins that bind to and stabilize the signle strands of DNA exposed when helicase unwinds the double helix in preparation for replication.






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






18. 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






19. A statistical rule stating that the probability of either of two indpendent (and mutually exclusive) events ocuring is the sum of their individual probabilities minus the probability of them both occuring together.






20. The final phase of the digestive tract - also called the colon. The primary funcion of the large intestine is to reabsorb water and to store the feces.






21. A thin - watery fluid found in teh anterior segment of the eye (between the lens and the cornea). THe aqueous humor is constantly produced and drained - adn helps to bring nutrients to the lesn and corena - as well as to remove metabolic wastes






22. Haploid cells resulting from the first meiotic division of spermatogenesis. Secondary spermatocytes are ready to enter meiosis II.






23. One of the four aromatic bases found in DNA and RNA. Guanine is a purine; it pairs with cytosine.






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






25. A structure composed of a ring of nine microtube triplets - found in pairs in the MTOC (microtubule organizing center) of a cell. The centrioles duplicate during the cell division - and serve as the organizing center for the mitotic spindle.






26. The characteristics of amolecule that has both polar (hydrophilic) and non - polar hydrophobic) regions - e.g. phospholipids - bile - etc.






27. A protein found in the plasma membrane of all cells in the body that uses the energy of an ATP (hydrolyzes ATP) to move three Na+ ions out of the cell and two K+ ions into the cell - thus establishing concentrations gradients for these ions across th






28. A bacterial extrachromosal elent that allows the bacterium to initati conjugation. Bacteria that possess teh F factor are known as F+ 'males'.






29. The first encounter with an antigen - resuling in activated B cells (antibody secretion) and T cells (cellular lysis and lymphocyte proliferation). The primary immune response takes approximately ten days - which long enough for symptoms of the infec






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






31. A layer of cells surroudning the granulosa cells of the follicles in an ovary. Thecal cells help produce the estrogen secreted from the follicle during the first phase of the ovarian cycle.






32. 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.'






33. A genotype in which two different alleles are possessed for a given gene.






34. A clear fluid the circulates around through the brain and spinal cord that helps to physially support teh brain and act as a shock absorber - and taht also exchanges nutrients and wastes with teh brain and spinal cord.






35. The depolarization of the egg plasma membrane upon fertilization - designed to prevent the entry of more than one sperm into the egg.






36. A hormone made of amino acids (in some cases just a single - modified amino acid). Peptide hormones are generally hydrophilic and cannot cross the plasma membranes of cells - thus receptor for peptide hormones must be found on the cell surface. An ex






37. A layer of connective tissue underneath the epidermis of the skin. The dermis contains blood vessels - lymphatic vessels - nerves - sensory receptors - and glands.






38. The flow of blood from the heart - through the body (not including the lungs) - and back to the heart.






39. The prokaryotic ribosome - binding site on mRNA - found 10 nucleotides 5' to the start codon.






40. A neuron that carries information (action potentials) away from the central nervous system; a motor neuron.






41. The curled structure in the inner ear that contains the membranes and hair cells that transduce sound waves into action potentials.






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






43. The portion of the nephron tubule after the loop of Henle - but before teh collecting duct. Selective reabsorption and secretion occur here - most notably regulated reabsorption of water and sodium.






44. A region of specialized cardiac muscle cells in the right atrium of the heart that initiate the impules of heart contraction; for this reason the SA node is knownas the 'pacemaker' of the heart.






45. One of two large vessels (superior and inferior) that return deoxygenated blood to the right atrium of the heart.






46. 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.






47. An enzyme inhibitor that binds at a site other than the active sit of an enzyme (binds at an allosteric site). THis changes the three - dimensional shape of the enzyme such that it can no longer catalyze the reaction






48. A protein channel in a cell membrane that is specific for a particular ion - such as Na+ or K+. Ion channels may be constitutively open (leak channels) - or regulated (voltage - gated or ligand - gated).






49. A non - protein - but organic - molecule (such as vitamin) that is covalently bound to an enzyme as part of the active site.






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