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. A small - extrachromosomal (outside the genome) - circular DNA molecule found in prokaryotes.






2. The tube that connects the middle ear acity with the pharynx; also known as the Eustachian tube. Its fucntion is to equalize midle ear pressure with atmospheric pressure so that pressure on boths sides of the tympanic membrane is the same.






3. The movement of a substance from the filtrate (in the renal tuble) bak into the bloodstream. Reabsorption reduces the amount of a substance in the urine.






4. The outermost layer of teh skin. The epidermis is made of epithelial tissue that is constantly dividing at the bottom; teh cells migrate to teh surface (dying along the way) to be sloughed off at the suface.






5. The mass of cells in the blastocyst that ultimately give rise to the embryo and other embryonic structues (the amion - the umbilical vessels - etc.)






6. A looser - more porous type of bone tissue found at the inner core of the epiphyses in long bones and all other bone types. Spongy gone is filed with red bone marrow - important in blood cell formation.






7. An ion channel that is constitutively open - allowing the movement of teh ion across the plasma membrane according to its concentration gradient.






8. The movement of air out of the respiratory tract. Expiration can be passive (caused by relaxation of the diaphragm and elastic recoil of the lungs) or active (caused by contraction of the abdominal muscles - which increases intraabdominal pressure an






9. The outer layer of smooth muscle in the wall of the digestive tract. When the longitudinal muscle contracts the tube shortens.






10. A short period of time **prior to exponential growth of a bacterial population during which no - or very limited - cell division occurs.






11. A receptor that responds to light






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






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






14. Anterior pituitary gland






15. A type of lipoprotein; the form in which absorbed fats from the intestines are transported to the circulatory system.






16. A region of specialized cardiac muscle cells in the right atrium of the heart that initiate the impules of heart contraction; for this reason the SA node is knownas the 'pacemaker' of the heart.






17. A cyclic version of adenosine monophosphate - where the phosphate is esterified to both the 5' and 3' carbons - forming a ring. Cyclic AMP is an important intracellular signaling moelcule - often called the 'second messenger.' It serves to activate c






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






19. A hormone produced by the C- cells of the thyroid gland that decreases serum calcium levels. It targets teh bones (stimulates osteoblasts) - the kidneys (reduces calcium reabsorption) - and the small intestine (decreases calcium absorption).






20. The second phase of the uterine (endometrial) cycle - during which the endometrium (shed off during menstration is rebuilt). This phase of the cycle is under the control of estrogen - secreted from the follicle developing in the ovary during this tim






21. The layer of ciliated - mucus - covered cells in the respiratory tract.The cilia continually beat - sweeping contaminated mucus upward toward the pharynx.






22. Bacteria that have a thick peptido glycan cell wall - and no outer membrane. They stain very darkly (purple) in Gram stain.






23. 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.






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






25. The enzymatic process of reading a strand of DNA to produce a complemenetary strand of RNA






26. The principal glucocorticoid secreted from teh adrenal cortex. This steroid hormone is released ruing stress - causing increased blood glucose levels and reducing inflammation. The latter effect has led to a clinical use of cortisol as an anti - infl






27. 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.






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






29. Zygot - derived projections that extend into the endometrium of the uterus during pregnancy. Fetal capillaries grow into the placental villi - which are surrounded by a pool of maternal blood. THis facilitates nutrient and gas exchange between the mo






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






31. The portion of the ear consisting of the pinna and the external auditory canal. The outer ear is separated from the middle ear by the tympanic membrane (the eardrum).






32. A situation in which a heterozygote displays the phenotype associated with each of the alleles - e.g. - human blood type AB.






33. The portion of the diencephalon involved in maintaining body homeostasis. the hypothalamus also controls the release of hormones from the pituitary gland.






34. 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.






35. A non - bony material that fills the hollow spaces inside bones. Red bone marrow is found in regiosn of spongy bone and is the site of blood cell (red and white) production. Yellow bone marrow is found in the diaphysis (shaft) of long bones - is most






36. A protein embedded in the lipid bilayer of a cell. These are typicallly cell surface receptors - channels - or pumps.






37. A carrier protein that transports two molecules acrss the plasma membrane in opposite directions.






38. The first (approximately 5%) of the small intestinte.






39. A short sequence of amino aids - usually found at the N- terminus of a protein being translated - that directs the ribosome and its associated mRNa to the membranes of the rough ER where trasnlation will be completed. Signal sequences are found on me






40. Multiple sites of replication found on large - linear eukaryotic linear eukaryotie chromosomes.






41. The mechanism described by Charles Darwin that drives evolution. Through mutation - some organisms possess genes that make them better adapted to their environment. These organisms survive and reproduce more than those that do not possess the benefic






42. Fingerlike projection of the uterin (fallopian) tubes that drape over the ovary.






43. A lubricating - nourishing fluid found in joint capsules.






44. An inactive precursor of an enzyme - activated by various methods (acid hydrolysis - cleavage by another enzyme - etc.)






45. The function unit of the kidney. Each kidney has about a million nehprons; this is where blood filtration and subsequent modification of the filtrate occurs. The nephron empties into collecting ducts - which empty into the ureter.






46. A hole in the center of the iris of the eye that allows light to enter the eyeball. The diameter of pupil is controlled by the iris in response to the brightness of the light.






47. Arise in blood pH due to hyperventilation (excessive breathing) and a resulting decrease in CO2.






48. (1) The integration of input (EPSPs and IPSPs) from many presynaptic neruons by a single postsynaptic neuron - either temporaly or spatially. Summation of al input can either stimulate the postsynaptic neuron and possibly lead to an action potential






49. 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.






50. An **organic molecuel taht associates non - covalently with an enzyme - and that is required for the proper functioning of the enzyme.