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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 secretion of a cellular product to the extracellular medium through a secretory vesicle.






2. 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.






3. A generic connective tissue cell that produces fibers; the progenitor of all other connective tissue cell types.






4. The percentage of individuals with a particular genotype that actually displays the phenotype associated with the genotype.






5. The mechanism that ensures tehat skeletal muscle contraction does not occur without neural stimulation (excitation). A trest - cytosolic [Calcium] is low - and the troponin - tropomyosin complex covers the myosin - binding sites on actin. When the mu






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






7. The shaft of a long bone. The diaphysis is hollow and is made entirely from compact bone.






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






9. Also known as the adenohypophysis - the anterior pituitary is made of gland tissue and makes and secretes six different homrones: FSH - LH - ACTH - prolactin - TSH - and growth hormone. The anterior pituitary is controlled b yreleasing and inhibiting






10. DNA replication in which each of the parental strands is read to make a complementary daughter strand - ethus each new DNa molecule is composed of half the parental molecule paired with a newly synthesized strand.






11. The point during development at which a cell becomes committed to a particular fate (sensory - other - etc.). Note that the cell is not differentiated at this point; determination comes before differentiation. Determination can be due to cytoplasmic






12. A four - subunit protein found in red blood cells that binds oxygen. Each subunit contains a heme group - a large multi - ring molecule with an iron atom at its center. One hemoglobin molecule can bind four oxygen molecules in a cooperative manner.






13. Early embryonic ducts that can develop into male internal genitalia under the proper stimulation (testosterone).






14. 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.






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






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






17. Also called occluding junctions - tight junctions form a seal between cells that prevents the movement of substances across the cell layer - except by diffusion through the cell membranes themselves. Tight junctions are found between the epithelial c






18. A bundle of skeletal muscle cells. Fascicles group together to form skeletal muscles.






19. A blood vessel that carries blood away from the heart chambers. Arteries have muscular walls to regulate blood flow and are typically high - pressure vessles.






20. 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.






21. (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.






22. A series of enzyme complexes found along the inner mitochondrial membrane. NADH and FADH2 are oxidized by tehse enzymes; the electrons are shuttled down the chain and are ultimately passed to oxygen and to produce water. The electron energy is used t






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






24. 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.






25. A type of syanpse in which the cells are connected by gap junctions - allowing ions (and therefore an action potential) to spread easily from cell to cell - usually in smooth and cardiac muscle. - compared to chemical synapse.






26. The physical characterisitcs resulting from the genotype. Phenotypes are usually described as dominant or recessive.






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






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






29. A molecule composed of two monosaccharides. Common disaccharides include maltose - sucrose - and lactose.






30. An RNA polymerase that creates a primer (made of RNA) initiate DNa replication. DNA pol binds to the primer and elongates it.






31. A clear fluid the circulates around through the brain and spinal cord that helps to physially support teh brain and act as a shock absorber - and taht also exchanges nutrients and wastes with teh brain and spinal cord.






32. The duct that carries bile from the gallbladder and liver to the small intestine (duodenum).






33. A fibrous - connective - tissue protein taht has the ability to recoil to its original shape after being stretche.d Elastin is found in great amounts in lung tissue - arterial tissue - skin - and the epiglottis.






34. A band of carilage (hyaline) found between the diaphysis and epiphyses of long bones during childhood and adolescence. Cell proliferation in the middle of the eiphyseal plate essentially forces teh diaphysis and epiphyses further apart - while the ol






35. An ion channel that is oepend or closed based on the electrical potential across the plasma membrane. Once opened - the channel allows ions to cross the membrane according to their concentration gradients. Examples are the Na+ and K+ voltage - gated






36. A network of membranes inside eukarytoic cells invovled in lipid synthesis (steroid in gonads) - detoxification (in liver cells) - and/or Ca2+ storage (muscle cells).






37. The pressure measured in the arteries while the ventricles are relaxed (during diastole).






38. The rapid mitotic division of a zygot that being within 24-36 hours after fertilization






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






40. 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.






41. The muscuar layer of the uterus. The myometrium is made of smooth muscles that retains its ability to divide in order to accomodate the massive size increases that occur during pregnancy. The myometrium is stimulated to contract during labor by the h






42. The fraction of teh end - diastolic volume ejected from the ventricles in a single contraction of teh heart. THe ejection fraction is normally around 60% of the end diastolic volume.






43. The birth canal; the stretchy - muscular passageway through which a baby exits the uterus during childbirth.






44. A type of mutation in DNa where a single base is substituted for another.






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






46. The formatino of the nervous system during weeks 5-8 of gestation. Neuralation begins when a section of the ectoderm invaginates and pinches off to form the neural groove - which ultimately forms the neural tube - From which the brain and spinal cord






47. A subphase of male orgasm. Emission is the movement of sperm (via the vas deferens) and semen into the urtehra in prepartion for ejaculation.






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






49. An activated B cell that is secreting antibody.






50. In the autonomic divison of the PNS - a neuron that has its cell body located in the CNS - and whose axon extends into the PNS to synapse with a second neuron at an autonoic ganglion. (The second neuron's axon synapses with the target axon)