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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 second step in viral infection - the injection of the viral genome into the host cell.






2. 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






3. The band of the sarcomere that extends the full length of the thick filament. The A band includes regions of thick and thin filament overlap - as well as a region of thick filament only. A bands alternate with I bands to give skeletal and cardiac mus






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






5. A cell surface receptor associated with an intracellular protein that binds and hydrolyzes GTP. When GTP is bound - the protein is active - and can regulate the activity of adenylyl cyclease; this modifies the intracellular levels of second messenger






6. 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






7. The reduced form of NAD+ (nicotinamide adenine dinucleotide). This is the most common electron carrier in cellular respiration.






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






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






10. The stage of human development during which the organs are formed. Organogenesis begins after gastrulation and is completed by the eight week of gestation.






11. 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)






12. Very small air tubes int eh respiratory system (diameter 0.5 - 1.0 mm). The walls of the bronchioles are made of smooth muscle (thus involunatry) to help regulate air flow.






13. A peptide hormone produced and secreted by the alpha cells - of the pancreas. It tartes primarily the liver - stimulating the breakdown of glycogen - thus increasing blood gluocse level.s






14. 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






15. 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.






16. 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.






17. Plasma with the clotting factors removed. Serum is often used in diagnostic tests because it does not clot.






18. The clear portion of the tough outer layer of teh eye ball - found over the iris and pupil






19. An alkaline - fructose - rich fluid produced by three different glands in the male reproductive tract and released during ejaculation. Semen is very nourishing for sperm.






20. An enzyme that phosphorylates something else. Kinases are frequently used in regulatory pathways - phosphorylating other enzymes.






21. A single piece of double - stranded DNA; part of the genome of an organism. Prokaryotes have circular chromosomes and eukaryotes have linear chromosomes.






22. A protein complex foudn in the inner membrane of the mitochondira. It is essentially a channel that llows H+ ions to flow from teh intermembrane space to the matrix (down teh gradeint produced by the enyzmes complexes of the electron transport chain)






23. A string of several hundred adenine nucletodies added to the 3' end of the eukaryotic mRNA.






24. 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.






25. 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.






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






27. The valvecontrolling release of bile and pancreatic juice into the bloodstream.






28. A sensory receptor that responds to mechanical disturbances - such as shape changes (being squashed - bent - pulled - etc.). Mechanoreceptors include touch receptors in the skin - hair cells - in the ear - muscle spindles - and others.






29. Toward the 5' end of an Rna transcript (the 5' end of the DNA coding strand). The promoter and start sites are upstream.






30. The pressure measured in the arteries during contraction of the ventricles (during systole).






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






32. Also called falopian tubes - these tubes extend laterally from their side of the uterus and serve as a passageway for the ocyte to travel from the ovary to the uterus. This is also the normal site of fertilization. Severing of the uterine tubes (tuba






33. A point mutation in which a pyrimidine is substitued for a purine - or vice versa.






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






35. 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.






36. A person with blood type O-. Because this person's red blood cells possess none of the typical blood suface proteins - they cannot initiate an immune reaction in a recipient.






37. Also called transverse tubules - these are deep invaginations of the plasma membrane found in skeletal and cardiac muscle cells. These invaginations allow depolarization of the membrane to quickly penetrate to the interior of the cell.






38. A law of population genetics that states that the frequencies of alleles in a given gene pool do not change over time. There are five assumptions required for this law to hold true: there must be no mutation - there must be no migration - there must






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






40. The division of the autonomic nervous system known as the 'resting and digesting' system. It causes a general decrease in body activities such as heart rate - respiratory rate - and blood pressure - and an increase in blood flow to the GI tract and d






41. The valve that controls the release of feces from the recturm. It has an internal part made of smooth muscle (thus involuntary) and an external part made of skeletal muscle (thus voluntary).






42. 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






43. (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






44. The ability of tissues to regulate their own blood flow in the absence of neural stiulation. THis is generally accomplished via metabolic wastes (such as CO2) that act as vasodilators.






45. An organism that makes its own - typically using CO2 as a carbon source.






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






47. Cytoskeletal filaments with a diameter in between that of the microtubule and the microfilament. Intermediate filaments are composed of many different proteins and tend to play structural roles in cells.






48. Large conglomerations of proteins - fats - and cholesterol that transport lipids in the bloodstream. (chylomicrons are a type of lipoprotein).






49. A long projection off the cell body of a neruon down which an action potential can be propagated.






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