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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. To remove oxygen - to add hydrogen - or to add electrons to a molecule.






2. 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.






3. Human Chorionic Gonadotropin - a hormone secreted by the trophoblast cells of a blasocyst (i.e. developing embryo) that prolongs the life of the corpus luteum - and thus increases the duration and amount of secreted progesterone. This helps to mainta






4. The first substrate in teh Krebs cycle - produced primarily from the oxidation of pyruvate by the pyruvate dehydrogenase complex - however acetyl - CoA is also produced during fatty acid oxidation and protein catabolism.






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






6. Microscopic outward folds of the cells lining the small intestine; microvilli serve to increase the surface area of the small intestine for absorption.






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






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






9. A microscopic space between the axon of one neuron and the cell body or dendrites of a secon neruon - or between the axon of a neuron and an organ.






10. A vein connecting the capillary bed of the intestines with the capillary bed of the liver. This allows amino acids and gluocse absorbed from the intestines to be delivered first to the liver for processing before being transported throughout the circ






11. A hormone secreted by the anterior pituitary that tarets the mammary glands stimulating them to produce breastmilk.






12. A duodenal enzyme that activates trypsinogen (from the pancreas) to trypsin.






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






14. The cord that connects the embryo of a developing mammal to the placenta in the uterus of the mother. The umbilical cord contains fetal arteries (carry blood toward the placenta) and veins (carry blood away from the placenta). The umbilical vessels d






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






16. A protein hormone secreted by sustenacular cells of the testes that acts to inhibit the release of FSH and LH from the anterior pituitary.






17. 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






18. A fibrous protein found on the intracellular side of the plasma membrane (also associated with the Golgi complex) that helps invaginate the membrane. Typically cel surface receptors are associated with clathrin - coated pits at the plasma membrane bi






19. The valves in the heart that separte the atria from teh ventricles. The tricuspid valve separates teh right atrium from the right ventricel - and the bicuspid (mitral) valves separates the left atrium from the left ventricle. These valves close at th






20. The contribution of an individual gas to the total ppressure of a mixture of gases. Partial pressures are used to describe the amounts of the various gases carried in the bloodstream.






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






22. A thick - gelatinous fluid found in the posterior segment of the eye (between the lens and the retina). The vireous humor is only produced during fetal development and helps maintain intraocular pressure (the pressure inside the eyeball).






23. The flow of blood from the heart - through the lungs - and back to the heart.






24. 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






25. (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.






26. A motor neuron and all the all the skeletal muscle cells it innervates. Large motor units are typically found in large muscles (e.g. - the thighs and buttocks) and produce fross movements. Small motor untis are found in smaller muscles (e.g. the rect






27. A hormone secreted by the small intestine (duodenum) in response to the presence of food. It decreases the rate at which chyme leaves the stomach and enters the small intestine.






28. The fertilization of an oocyte by more than one sperm. This occurs in some animals - but in humans - blocks to polyspermy exist (the fast block and the slow block) so that only a single sperm can penetrate the oocyte.






29. 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






30. The portion of the hindbrain that controls respiratory and blood pressure - and specialized digestive and respiratory functions such as vomiting - sneezing - and coughing.






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






32. A passageway leading from behind the nasal cavity to the trachea. The pharynx is divided into three regions - named for their location. The nasopharynx is behind the nasal cavity - the oropharynx is behind the oral cavity - and the laryngopharynx is






33. 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.






34. The cellular elements of blood; erythrocytes - leukocytes - and platelets.






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






36. 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.






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






38. 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.






39. 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.






40. Paired glands near the posterior side of the vaginal that secrete an alkaline mucus upon sexual arousal. The mucus helps to reduce the acidity of the vagina (which could be harmful to sperm) and lubricates the vagina to facilitate penetration.






41. An organism that has two copies of its genome it each cell. The paired genomes are said to be homologous.






42. The movement of air into the respiratory tract. Inspiration is an active process - requiring contraction of the diaphragm.






43. 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.






44. A globular protein found in muscle tissue that has the ability to bind oxygen. Myoglobin helps to store oxygen in the muscle for use in aerobic respiration (it does not move - just stays there). Muscles that participate in endurance activities (inclu






45. A mature - dormant osteoblast.






46. 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.






47. The outer layer of an organ - e.g. the renal cortex - the ovarian cortex - the adrenal cortex - etc.






48. The 'blind spot' of the eye - this is where the axons of the ganglion cells exist the retinal to form the optic nerve. There are no photoreceptors in the optic disk.






49. Specialized tissue with a lot of space that can fill with blood upon proper stimulation - causing teh tissue to become firm. Erectile tissue is found in the penis - the clitoris - the labia - and the nipples.






50. The primary enzyme in peroxisomes; catalse catalyzes the hydrolysis of hydrogen peroxide (H2O2) into water and oxygen.