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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. Strong bands of connective tissue that connect skeletal muscle to bone.






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






3. 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.






4. A pair of similar chromosomes that have the same genes in the same order - but may have different versions (alleles) of those genes. One of the pair of chromosomes came from Mom in an ovum - and the other came from Dad in a sperm. Humans have 23 pair






5. A self - initiating action potential that occurs in the conduction system of the heart and triggers action potentials (and thus contraction) in the cardiac muscle cells Tee pacemaker potential is triggered by the regular - spontaneous depolarization






6. The valves in the heart that separate the ventricles from the arteries. The pulmonary semilunar valve separates the right ventricle from the pulmonary artery - and the aortic semilunar valve separates left ventricle from the aorta. These valves close






7. 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






8. Human Chorionic Gonadotropin - a hormone secreted by the trophoblast cells of a blasocyst (i.e. developing embryo) that prolongs the life of the corpus luteum - and thus increases the duration and amount of secreted progesterone. This helps to mainta






9. A type of substrate binding to a multi - active site enzyme - in which the bnidng of one substrate molecule facilitates teh binding of subsequent substrate molecules. A graph of reaction rate vs. substrate concentration appears sigmoidal. Noe that co






10. 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






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






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






13. 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.






14. Pain receptors. Nociceptors are found everywhere in the body except for the brain.






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






16. An enzyme that cuts one or both strands of DNa to relieve the excess tension caused by the unwinding of the helix by helicase during replication.






17. 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






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






19. Cells that form the walls of the seminiferous tubules and help in spermatogenesis Sertoli cells are also called susenacular cells.






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






21. A haploid but immature cell resulting from the second meiotic division f spermatogenesis. Spermatids undergo significant physical changes to become mature sperm (spermatozoa).






22. The phase of the cell cycle during which the genome is replicated.






23. A sensory receptor that responds to specific chemicals. Some examples are gustatory (taste) receptors - olfactory (smell) receptors - and central chemoreceptors (responds to pH changes in teh cerebrospinal fluid).






24. 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






25. The enzyme that breaks down acetylcholine in the synaptic cleft.






26. An organism that can survive in the presence of oxygen (oxygen is not toxic) - but that does not use oxygen during metabolism (anaerobic metabolism only).






27. The maximum amount of air that can be forcibly exhaled from the lungs after filling them to their maximum level - typically about 4500 mL






28. An electrical potential established across the plasma membrane of all cells by the Na+/K+ ATPase and the K+ leak channels. In most cells - the resting membrane potential is approximately -70 mV with respect to the outside of the cell.






29. The volume of air remaining in the lungs after a maximal forced exhalation - typically about 1200 mL.






30. A pathway through a plasma membrane that restrics passage based only on the size of the molecules. Pore are made from porin proteins.






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






32. The unit of combact bone - also called a Haversian system. Osteons are essentially long cylinders of bone; the hollow center is called the central canal - and is where blood vessels - nervs - and lymphatic vessels are found. Compact bone is laid down






33. The flow of blood through a tissue; ischeia is when there is no blood flow - anoxia when there is no O2 available (ischemia is more dangerous b/c of waste build - up)






34. The reactants in an enzyme - catalyzed reaction. Substrate binds at the active site of an enzyme.






35. MRNA that codes forsingle type of protein - such as is found in eukaryotic cells.






36. 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.'






37. 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.






38. A pigment produced by melanocytes in teh bottom cell layer of the epidermis. Melanin production is increased on sun exposure and helps prevent cllular damage due to UV radiation.






39. A chemical derived from vitamin A found in the pigment proteins of the rod photoreceptors of the retina. Retinal changes conformation when it absorbs light - triggering a series of reactions that ultimately result in an action potential being sent to






40. A protein - digesting enzyme secreted by the chief cells of the gastric glands. Pepsin is secreted in its inactive form (pepsinogen) and is activated by gastric acid. It is unusual in that its pH optimum is around 1-2; most of these enzymes in the bo






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






42. A long - coiled duct on the outside of the testis in which sperm mature.






43. Salivary amylase






44. 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.






45. A cytoplasmic protein that recognizes the signal sequences of proteins destined to be translated at the rough ER. It binds first to the ribosome translating the protein with the signal sequence then to an SRP receptor on the rough ER>






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






47. A vein connecting the capillary bed of the intestines with the capillary bed of the liver. This allows amino acids and gluocse absorbed from the intestines to be delivered first to the liver for processing before being transported throughout the circ






48. The membranes that line the surface of the lungs (visceral pleura) and the inside wall of the chest cavity (parietal pleura).






49. The RF value - the percentage of recombinant offspring resulting from a given genetic cross. The recombination frequency is proportional to the physical distance between genes on a chromosome. If a recombination frequency is low - the genes under con






50. An organism (such as a fungus) that feeds of dead plants and animals.