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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. A subphase of male orgasm - a reflex reaction triggered by the presence of semen in the urethra. Ejaculation is a series of rhythmic contractions of muscles near teh base of teh penis that increase pressure in the urethra - forcing the semen out.






2. The failure of homologous chromosomes or sister chromatids to separate properly during cell division. This could ocur during anaphase I of meiosis (homologous chromosomes) [--> leaving 2 gametes w/ 2 copies and 2 gametes w/ no copies of chromosome] -






3. 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.






4. (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.






5. Small fragments of DNa produced on the lagging strand during DNa replication - joined later by DNA ligase to form a complete strand.






6. Very small tube or channel - such as is found between lacunae (connecting them together) in compact bone.






7. The outer protein coat of a virus (the whole coat)






8. A globular protein that ssociated with tropomyosin as part of the thin filament of the sarcomere. Troponin binds Ca2+ - which causes the conformaiton change in tropomyosin required to expose the myosin - binding sites on actin and initiate muscle con






9. An enzyme that unwinds the double helix of DNA and separates the DNA strands in preparation for DNA replication.






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






11. A tropic hormone produced by the anterior pituitary gland that targets the thyroid gland - stimulating it to produce and release thyroid hormone.






12. 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).






13. 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.






14. Mendel's seond law. States that genes found on different chromosomes - or genes found very far apart on the same chromosome (i.e. - unlinked genes) sort independently of one another during gamete formation (meiosis).






15. The specific site on an antigenic molecule that binds to a T cell receptor or to an antibody.






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






17. A large - mature - ovarian follicel with a well - developed antrum and a secondary oocyte. Ovulation of the oocyte occurs from this type of follicle.






18. A hormone derived from cholesterol. Steroids are generally hydrophobic and can easily cross the plasma membrane of cells - thus receptors for steroids are found intracellularly. Once this steroid binds to its receptor - the receptor - steroid complex






19. A molecule formed by joining many monosaccharides together. POlysaccharides are typically energy- storage molecules (glycogen in animals - starch in plants) or structural molecules (cellulose in plants - chitin in exoskeletons).






20. A nucleotide sequence in RNA that contains protein - coding information. Exons are typically separated by introns (intervening sequences) that are spliced out prior to translation.






21. The portion of the digestive tract that stores and grinds food. Limited digestion occurs in the somach - and it has the lowest pH in the body (1-2).






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






23. The RF value - the percentage of recombinant offspring resulting from a given genetic cross. The recombination frequency is proportional to the physical distance between genes on a chromosome. If a recombination frequency is low - the genes under con






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






25. A chemical derived from vitamin A found in the pigment proteins of the rod photoreceptors of the retina. Retinal changes conformation when it absorbs light - triggering a series of reactions that ultimately result in an action potential being sent to






26. The third phase of mitosis. During anaphase - replicated chromosmes are split apart at their centromeres (the sister chromatids are separated from each other) and moved to opposite sides of the cell.






27. The elimination of wastes from the body.






28. Mendels' first law. The Law of Segregation states that the two alleles of a given gene will be separate from one another during gamete formation (meiosis).






29. In the autonomic division of the PNS - a neuron that has its cell body located in the autonomic ganglion (where a preganglionic neuron synapses with it) and whose axon synapses with the target axon.






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






31. Strong contractions of the uterus (stimulated by oxytoncin) that force a baby out of the mother's baby during childbirth. Labor contractions are part of a positive feedback cycle - during which the baby's head stretches the cervix - which stimulates






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






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






34. A protein - digesting enzyme secreted by the chief cells of the gastric glands. Pepsin is secreted in its inactive form (pepsinogen) and is activated by gastric acid. It is unusual in that its pH optimum is around 1-2; most of these enzymes in the bo






35. A receptor that responds to changes in body position - such as stretch on a tendon - or contraction of a muscle. These receptor allow us to be consciously aware of the position of our body parts.






36. (1) The secretion of useful substances from a cell - either into the blood (endocrine secretin) or into a cavity or onto the body surface (exocrine secretion). (2) in the nephron - the movement of substances from the blood to the filtrate along the t






37. A mature - dormant osteoblast.






38. A contractile protein. In skeletal and cardiac muscle - actin polymerizes (along with other proteins) to form the thin filaments. Actin is involved in many contractile activities - such as cyotkinesis - pseudopod formation - and muscle contraction.






39. One of several vessels that carry oxygenated blood from the lungs to the left atrium of the heart.






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






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






42. An organism that has only a single copy of its genome in each of its cells. Haploid organisms possess no homolous chromosomes.






43. The string between beads of DNA on histones. They are also wrapped around a single histone - called linker histone - may not really have to know..






44. An enzyme whose transcription can be stopped by an abundance of its product (as opposed to inducible enzymes). Usually part of anabolism of product.






45. The movement of molecules through the plasma membrane against their concentration gradients. Active transport requires input of cellular energy - often in the form of ATP. An example is the Na+/K+ ATPase in the plasma membrane of all cells.






46. Pepsinogen - secreting cells foudn at teh bottom of the gastric glands






47. The primary androgen (male sex steroid). Testosterone is a steroid hormone produced and secreted by the interstitial cells of the testes. It triggers the development of secondary male sex characteristics during puberty (including spermatogenesis) and






48. The curled structure in the inner ear that contains the membranes and hair cells that transduce sound waves into action potentials.






49. A large - ring shaped lipid found in cell membranes. Cholesterol is the precursor for steroid hormones - and is used to manufacture bile salts.






50. Receptors in the central nervous system that monitor the pH of cerebrospinal luid to help regulate ventilation rate.