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






2. The specific location on a DNa strand where replication begins.. Prokaryotes typically have a single origin of replication - while eukaryotes have several per chromosome.






3. A type of synapse at which a chemical (a neurotransmitter) is released from teh axon of a neuron into the ysnaptic cleft where it binds to receptors on the next structure in sequence - either another neuron or an organ.






4. The specific site on an antigenic molecule that binds to a T cell receptor or to an antibody.






5. Multiple sites of replication found on large - linear eukaryotic linear eukaryotie chromosomes.






6. The regino of the sarcomere made up only of thin filaments. The I band is bisected by a Z line. I bands alternate with A bands to give skeletal and cardiac muscle a striated appearance. I bands get shorter (and may disappear completely) during muscle






7. 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






8. The non - specific uptake of liquid particles into a cell by invagination of the plasma membrane and subsequent 'pinching off' a small bit of the extracellular fluid.






9. Gaps in the myelin sheath of the axons of peripheral neruons. Action potentials can 'hump' from node to node - thus increasing the speed of conduction (saltatory conduction).






10. A bacterium having a spiral shape (plural = spirochetes)






11. A normal blood protein produced by the liver - angiotensin is converted to angiotensim I by renin (secreted by kidney when blood pressur falls). Angiotensin I si further onverted to angiotensim II by ACE (angiotensin converting enzyme). Angiotensin I






12. A neuron that arries information (action potentials) to the central nervous system; a sensory neuron.






13. 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.






14. The depolarzation of the motor end plate on a muscle cell.






15. Having the ability to become anything; a zygote is totipotent.






16. A bacterium having a rod - like shaped (plural = bacilli).






17. 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.






18. A form of evolution in which the same organism is placed into different environments with different selection pressures. This causes organisms to evolve differently - to diverge from their common ancestor. The resulting (new) species may share struct






19. The oxidation of high - energy electron carriers (NADH and FADH2) coupled to the phosphorylation of ADP - producing ATP. In eukaryotes - oxidative phosphorylation occurs in the mitochondira.






20. A constant input to the arteries that keeps them somewhat constricted to maintain a basal level of blood pressure.






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






22. Very small tube or channel - such as is found between lacunae (connecting them together) in compact bone.






23. Inhibitory postsynaptic potential; a slight hyperpolarization of the postysynaptic cell - moving the membrane potential of that cell further from threshold.






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






25. A bacterial structure formed in unfavorable growth conditions. Endospores have very rough outer shells made of peptidoglycan and can survive harsh conditions. The bacterium inside the endospore is essentially dormant and can become active (called ger






26. Produced in muscle cells from the reduction of pyruvate (under anaerobic conditions) to regenerate NAD+ so that glycolysis can continue. A rise in lactic acid usually accompanies an increase in physical activity.






27. The mechanism described by Charles Darwin that drives evolution. Through mutation - some organisms possess genes that make them better adapted to their environment. These organisms survive and reproduce more than those that do not possess the benefic






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






29. Physical structures in two different organism that have funcitonal similarity due to their evoluntion in a common environment - but have different underlying structure. Analogous structures arise from convergent evolution.






30. Plasma with the clotting factors removed. Serum is often used in diagnostic tests because it does not clot.






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






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






33. The combination of alleles of an organism carries. In a homozygous genotype - both alleles are the same - whereas in a heterozygous gentorype the alleles are different.






34. A gene appearing in a single copy in diploid organisms - e.g. X- linked genes in human males.






35. A function in the reproductive system - controlled by the parasympathetic nervous system - that includes erection (via dilation of erectile arteries) and lubrication.






36. A cell produced when a B cell is activated by antigen. Memory cells do not actively fight the current infection - but patrol the body in case of future infection with the same antigen. If the antigen should appear again the future - memory cells are






37. The portion of the ear consisting of the pinna and the external auditory canal. The outer ear is separated from the middle ear by the tympanic membrane (the eardrum).






38. The movement of air out of the respiratory tract. Expiration can be passive (caused by relaxation of the diaphragm and elastic recoil of the lungs) or active (caused by contraction of the abdominal muscles - which increases intraabdominal pressure an






39. An organism that relies on a chemical source of energy (such as ATP) instead of light (which phototrophs).






40. A blood vessel that carries blood toward the heart chambers. Veins do not have muscular walls - have valves to ensure that blood flows in one direction only - and are typically low - pressure vessels.






41. A phase in the cycle between mitosis and S phase (G1) or between S phase and mitosis (G2). During gap phases the cell undergoes normal activity and growth; G1 may include preparation for DNA replication and G2 includes preparation for mitosis. Note t






42. An organelle surrounded by a double=membrane (two lipid bilayers) where ATP production takes place. The interior (matrix) is where PDC and the Krebs cycle occur - and the inner membrane contains the enzymes of the electron trasport chain and ATP synt






43. One of the four basic tissue types in the body (epithelial - connective - muscle - and nervous). Connective tissue is a supportive tissue consisting of a relatively few cells scattered among a great deal of extracellular material (matrix) - and inclu






44. The first phase of meiosis II. Prophase II is identical to mitotic prophase - except that the number of chromosomes was reduced by half during meiosis I.






45. High frequency of recombination bacterium An F+ bacterium that has the fertility factor integrated into its chromosome. When conjugation takes place - it is able to transfer not only the F factor - but also its genomic DNA.






46. A form of genetic recombination in bacteria in which plasmid and/or genomic DNA is transferred from one bacterium to the toher through a conjugation bridge.






47. DNA replication in prokaryotes - so named because as replication proceeds around the single - circular chromosome - it takes on the appearnce of the Greek letter theta.






48. An abdominal organ that is considered part of the immune system. THe spleen has four functions: (1) it filters antigen from the blood (2) it is the site of B cell maturation - (3) it stors blood - and (4) it destroys old red blood cells.






49. A version of a gene. For example - the gene may be for eye color - and the allels include those for brown eyes - those for blu e eyes - those green eyes - etc. At most - dploid organsims can posses only two alleles for a given gene - one on each of t






50. Muscle tissue found in the walls of hollow organs - e.g. - blood vessels - the digestive tract - the uterus - etc. Smooth muscle is non - striated - uninucleate - and under involuntary control (controlled by the autonomic nervous system).