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. Small organelles that contain the hydrogen peroxide produced as a byproduct of lipid metabolism. Peroxisomes convert hydrogen peroxide to water and oxygen by way of the enzyme catalase.






2. Also known as the neurohyophysis - the posterior pituitary is made of nervous tisssue and stores and secretes two hormones made by the hypothlamus; oxtytocin and ADH. The posterior pituitary is controlled by action potentials from the hypothalamus.






3. The sequence of nucleotides on a chromosome that activates RNA polymerase so that transcription can take place. The promoter is found upstream of the start site - the location where transcription actually takes place.






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






5. An organism that requires the aid of a host organism to survive - and that harms the host in the process.






6. A relatively direct connection between a sensory neuron and a motor neuron that allows an extremely rapid response to a stimulus - often without conscious brain involvement.






7. The period of human development from implantation through 8 weeks of gestation. Gastrulation - neurulation - and organogenesis occur during this time period. The developing baby is known as embryo during this time period.






8. Three loop - like structures in the inner ear that contain sensory receptors to monitor balance.






9. A molecule (usually a protein) capable of initiating an immune repsonse (antibody production).






10. Photoreceptors in the retina of the eye that responds to bright light and provide color vision.






11. A viral life cycle in which the host is turned into a 'virus factory' and ultimately lysed to release the new viral particles.






12. 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).






13. The reduction of pyruvate to either ethanol or lactate in order to regenerate NAD+ from NADH. Fermentation occurs in the absence of oxygen - and allow glycolysis to continue under those conditions.






14. The resistance to blood flow in the systemic circulation. Peripheral resistance increases if arteries constrict (diameter decreases) - and an increase in peripheral resistance leads t o an increase in blood pressure.






15. The mechanism of contraction in skeletal and cardiac muscl cells. It is a series of four repeated steps: (1) myosin binds actin - (2) myosin pull actin toward the center of the sarcomere (3) myosin releases actin - and (4) myosin resets to its high -






16. The outer ring of cells of a blastocyst. The trophoblast takes part in the formation of the placenta.






17. A long - whip - like filament that helps in cell motility. Many bacteria are flagellated - and sperm are flagellated.






18. The largest of the cytoplasmic filaments. Microtubules are composed of two types of protein - alpha tubulin and beta tubulin. They are dynamic fibers - constantly being built up and broken down - according to cellular needs. Microtubules form the mit






19. (1) In the GI tract - organs that play a role in digestion but not directly part of the alimentary canal. These include the liver - the gallbladder - the pancreas - adn the salivary glands.






20. A hormone produced from vitamin D that acts in essentially the same manner as parathyroid hormone.






21. The valve that regulates the passage of chyme from the stomach into the small intestine.






22. 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.






23. A string of sarcomeres with a skeletal muscle cell (hence smaller than myofiber). Each muscle cell contains hundreds of myofibirils.






24. Aromatic bases found in DNa and RNA that have a single - ring structure. They include cytosine - thymine - and uracil.






25. The modifaction of enzyme activity through interactino of molecules with specific sites on the enzyme other than the active site (called allosteric sites)






26. The smallest (and final) fibers in the cardiac conduction system. The Purkinje fibers transmit the cardiac impulse to the ventricular muscle.






27. 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






28. A diploid cell formed by the fusion of two gametes during sexual reproduction.






29. 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.






30. The intracellular process triggered by the binding of a ligand to its receptor on the cell surface. Typically this activates seond messenger pathways.






31. A small cell with extremely little cytoplasm that results from the unequal cytoplasmic divsion of the primary (produces the first polar body) and the secondary (produces the second polary body) oocytes during meiosis (oogenesis). The polar bodies deg






32. 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).






33. The maintenance of relatively constant internal conditions (such as temperature - pressure - ion balance - pH - etc.) regardless of external conditions.






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






35. The interior of a mitochondrion (the region bounded by the inner membrane). - The matrix is the site of action of pyruvate dehydroganse complex and the Krebs cycle.






36. A strong band of connective tissue that connets bones to one another.






37. The release of milk from the mammary glands via contraction of ducts within the glands. Contraction is stimulated by oxytocin - which is released from the posterior pituitary when the baby begins nursing.






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






39. 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.






40. 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.






41. An enzyme present in erythrocytes (as well as in other places) that catalyzes the conversion of CO2 and H2O into carbonic acid (H2CO3).






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






43. A strong connective tissue with varying degrees of flexibility. (1) Elastic cartilage is the most flexible - forming structures that reuqire support but also need to bend - such as the epiglottis and outer ear. (2) Hyaline cartilage is more rigid tha






44. A viral enzyme that makes a strand of RNA by reading a strand of RNa . All prokaryotic and eukaryotic RNa polymerases are DNa dependent; they make a strand of RNa by reading a strand of DNA.






45. The theory that mitochondria and chloroplasts originated as independent unicellular organsims living in symbiosis with larger cells






46. Aromatic bases found in DNA and RNA that are derived from purine. They have a double rightn structure and include adenine and guanine.






47. An enzyme whose transcription can be stimulated by an abundance of its substrate (as opposed to repressible enzyme). Usually in catabolism.






48. The movement of a substance across a membane via pressure. In the kidney - filtration refers specifically to the movement of plasma across the capillary walls fo the glomerulus - into the capsule and tubule of the neprhon. Filtration at teh glomerulu






49. The monomer of a carbohydrate. Monosaccharides have the general chemical formula CnH2nOn - and common monosaccharides include glucose - fructose - galactose - and ribose.






50. The layer of connective tissue directly under the mucosa of an open body cavity.