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






2. One of the four aromatic bases found in RNA. Uracil is pyrimidine; it pairs with adnenine.






3. Paired masses of lymphatic tissue near the back of the throat that help trap inhaled or swallowed pathogens.






4. The 28 days of the menstrual cycle as they apply to the events in the uterus. The endometrial cycle is also known as the uterine cycle - and has the three subphases: menstruation - the proliferative phase - and the secretory phase.






5. The small artery that carries blood toward the capillaries of the glomerulus.






6. (singular alveolus.) Tiny sacs - with walls only a single cell layer thick found at the end of the respiratory bronchiole tree. Alveoli are the site of gas exchange in the respiratory system.






7. A prokaryotic enzyme used to twist teh single circular chromosome of prokaryotes upon itself to form supercois. Supercoiling helps to compact prokaryotic DNa and make it sturdier.






8. Lacking a blood supply; cartialge is an example of this






9. Small convoluted tubules in the testes where spermatogenesis takes place.






10. A form of evolution in which different organisms are placed into the same environment and exposed to teh same selection pressures. This causes the organisms to evolve along similar lines. As a result - they may share functional - but not structural s






11. The amount of blood returned to heart by the vena cavae.






12. The region of the nephron that surrounds the glomerulus. The capsule ollects the plasma that is filtered from teh capillaries in the glomerulus.


13. 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.






14. Swelling of tissues - sometimes caused by inflammation letting into many white blood cells (decreasing oncotic pressure at the end of the capillaries & not letting as much water back into capillaries & staying in tissues).






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






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






17. The percentage of wholeblood made up of erythrocytes The typical hematocrit value is between 40-45%.






18. The white portion of teh tough outer layer of the eyeball






19. An enzyme that transcribes RNa. Prokaryotes have a single RNA pol - while eukaryotes have three; in eukaryotes - RNA pol I transcribes rRNA - RNA pol II transcribes mRNA - and RNA pol III transcribes tRNA.






20. The collection of fluid in the alveoli - particularly dangerous because it impedes gas exchange. Common causes of pulmonary edema are increased pulmonary blood pressure or infection of the respiratory system.






21. The first portion of the nephron tubuel after the glomerulus. THe PCT is the site of most reabsorption; all filtered nutrients are reabsorbed here as well as most of the filtered water.






22. A lipid bilayer that surrounds the capsid of an animal virus. the envelope is acquired as teh virus buds out through the plasma membrane of its host cell. Not all annimal viruses possess and envelope.






23. Small paired gland found inferior to the prostate in males and at the posterior end of the penile urethra. They secrete an alkaline mucus on sexual arousal that helps toneutralize any traces of acidic urine the urethra that might be harmful to sperm.






24. The fourth of meiosis I. Telophase I is identical to mitotic telophase - except that the number of chromosoms is now reduced by half. After this phase the cell is considered to be haploid. Note however - that the chromosomes are still replicated - an






25. The formation of haploid gametes (sperm or ova) via meiosis.






26. An energy storage molecule used by muscle tissue. The phosphate from creatine phosphate can be removed and attached to an ADP to generate ATP quickly.






27. The darkly pigmented middle layer of the eyeball - found between teh sclera (outer layer) and the retina (inner layer).






28. The primary muscle of inspiration. The diaphragm is stimulated to contract at regular intervals by the respiratory center in the medulla oblongata (via the phrenic nerve). Although it is made of skeletal muscle (and can therefore be voluntary control






29. The inner epithelial lining of the uterus that thickens and develops during the menstrual cycle - into which a fertilized ovum can implant - and which sloughs off during menstration if a pregnancy does not occur.






30. An intracellular chemical signal (such as cAMP ) that relays instructions from the cell surface to enzymes in the cytosol.






31. A complex polymer of sugars and amino acids; the substance From which bacterial ell walls are made.






32. A junction between cells - consisting of a protein channel called a connexon on each of the two cells that connect to form a single channel between teh cytoplasms of both cells. Gap junctions allow small molecules to flow between teh cells - and are






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






34. An X- linked recessive disorder in Which blood fails to clot properly - leading to excessive bleeding if injured.






35. A gland that secretes a waxy product - found in the external ear canal.






36. 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






37. An organism that makes its own - typically using CO2 as a carbon source.






38. 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).






39. 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.






40. MRna that codes for several different proteins by utliizing different reading frames - nested genets - etc. Polycistronic mRNa is a characteristic of prokaryotes.






41. A tropic hormone produced by the anterior pituitary gland that targets the gonads. In females - FSH stimulates the ovaries to develop follicles (oogenesis) and secrete estrogen; in males - FSH stimulates spermatogenesis.






42. Sperm production; occurs in human males on a daily basis from puberty until death. Spermatogenesis results in the production of four mature gametes (sperm) from a single precursor cell (spermatogonium). For maximum sperm viability - spermatogenesis r






43. The inside of the a hollow organ (e.g. - the somach - intestines - bladder - etc.) or a tube (e.g. - blood vessels - ureters - etc.)






44. The division of the peripheral nervous system that innervates and controls the skeletal muscles; also known as the voluntary nervous system.






45. To attach oxygen - to remove hydrogen - or to remove electrons from a molecule.






46. A skeletal muscle cell - also known as a muscle fiber. Skeletal muscle cells are formed from the fusion of many smaller cells (during development) consequently they are very long and are multinucleate.






47. A diploid cell that can undergo mitosis to form more spermatogonium - and can also be triggered to undergo meiosis to form sperm.






48. A systme of ductless glands taht secrete chemical messengers (into) the blood - has to be into the blood.






49. A protein complex foudn in the inner membrane of the mitochondira. It is essentially a channel that llows H+ ions to flow from teh intermembrane space to the matrix (down teh gradeint produced by the enyzmes complexes of the electron transport chain)






50. 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).