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. The force required to resist the movement of water by osmosis. Osmotic pressure is essentialy a measure of the concentration of a solution. A solution that is hyighly concnetrated has a strong tendency to draw water into itself - so the pressure requ






2. A sequence of amino acids (usually basic) that directs a protein to the nuclear envelope - where it is imported by a specific transport mechanism.






3. 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.






4. A regulatory protein that binds DNA at a specific nucleotide sequence (sometimes known as the operator) to prevent transcription of downstream genes.






5. Large conglomerations of proteins - fats - and cholesterol that transport lipids in the bloodstream. (chylomicrons are a type of lipoprotein).






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






7. Also known as the gastrointestinal (GI) tract of the digestive tract - the alimentary canal is the long muscular 'tube' that includes the mouth esophagus - somatch - small intesitne - and large intestine.






8. 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.






9. An organism that can only survive in the absence of oxygen (anaerobic metabolism); oxygen is toxic to obligate anaerobes.






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






11. One of the two ends of long bone (pl: eiphyses). The epiphyses have an outer shell made of compact bone and inner core of spongy bone. The spongy bone is filled with red bone marrow - the stie of blood cell formation.






12. A point mutation in which a pyrimidine is susbstituted for a pyrimidine - or a purine is substituted for a purine.






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






14. The membrane that separate the outer ear from the middle ear. The tympanic membrane is also known as the eardrum.






15. In skeleta and cardiac muscle tissue - a filament composed of actin - tropomyosin - and troponin. Thin filaments are attached to teh Z lines of the sarcomers and slide over thick filaments during muscle contraction.






16. Formerly called the cardiac sphincter - this sphincter marks the entrance to the stomach. Its function is to prevent reflux of acid stomach contents into the esophagus; note that it does **not regulate entry into the stomach.






17. A neuron with a single axon and multiple dendrites; the most common type of neuron in the nervous system.






18. The ability of tissues to regulate their own blood flow in the absence of neural stiulation. THis is generally accomplished via metabolic wastes (such as CO2) that act as vasodilators.






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






20. The structure in the cochlea of the inner ear made up of the basilar membrane - the auditory hair cells - and the tectorial membrane. The Organ of Corti is the site where auditory sensation is detected and transduced to action potentials.






21. A specific DNA nucleotide sequence where transcriptional regulatory proteins can bind.






22. A cyoplasmic Ca2+- binding protein. Calmodulin is particularly important in smooth muscle cells - where binding of Ca2+ allows calmodulin to activate myosin light - chian kinase - the first step in smooth muscle cell contraction.






23. 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






24. An organism that cannot make its own food - and thus must ingest other organisms.






25. The normal configuration of double - stranded DNA in which the 5' end of oen strand is paired with the 3' end of the other






26. A viral life cycle in which the viral genome is incorporated into the host genome where it can remain dormant for an unspecified period of time. Upon activation - the viral genome is excised from the host genome and typically enters the lytic cycle.






27. 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)






28. The ends of a saromere.






29. Enzymes that degrade various macromolecules and that require an acidic pH to function properly. Acid hydrolases are found within the lysosomes of cells.






30. A chemical secreted by a T cell (usually the helper Ts) that stimulates activation and proliferation of other immune system cells.






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






32. A bacterial enzyme that recognizes a specific DNA nucleotide sequence and that cuts the double helix at a specific site within the sequence.






33. 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






34. A mature - dormant osteoblast.






35. A method of DNA protection utilized by prokaryotes in which their large circular chromosome is coiled upon itself.






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






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






38. The second most common of the five classes of leukocytes. Lymphocytes are involved in specific immunity and include two cell types - B- cells and T cells. B- cells produce and secrete antibodies and T- cells are invovled in cellular immunity.






39. The liquid portion of blood; plasma contains water - ions - buffers - sugars - proteins - etc. Anything that dissolves in blood dissolves in the plasma portion.






40. The most common class of bone in the body - long bones have a well - defined shaft (the diaphysis) and two well - defined ends (the epiphyses).






41. 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






42. The membrane that separates the middle ear from the inner ear.






43. A blood pressure cuff






44. The first generation of offspring from a given genetic cross.






45. The third stage of cellular respiration - in which acetyl - CoA is combined with oxaloacetate to form citric acid. The citric acid is then decarboxylated twice and isomerized to recreate oxaloacetate. In the process - 3 molecules of NADH - 1 molecule






46. Pepsinogen - secreting cells foudn at teh bottom of the gastric glands






47. Active transport that releies on an established concentration gradient - typically set up by a primary active transporter. Secondary active transport relies on ATP indirectly.






48. A life cycle of animal viruses in which the mature viral particles bud from the host cell - acquiring an envelope (a coating of lipid bilayer) in the process.






49. Ribosomal RNA; the type of RNA that associates with ribosomal proteins to make a functional ribosome. It is thought that the rRNA has the peptidyl transferase activity.






50. 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.