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 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






2. (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






3. Salivary amylase






4. 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.






5. A neuron - to - neuron - neuron - to - organ - or muscle to cell - to - muscle cell junction.






6. 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






7. Anterior pituitary topic hormones FSH (follicle stimulating hormone) and LH (luteinizing homeon) that stimulates the gonads (testes and ovaries) to produce gametes and to secrete sex steroids.






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






9. The largest artery in teh body; the aorta carries oxygenated blood away from the left ventricle of the heart.






10. The portion of the brain responsible for visual and auditory startle reflexes.






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






12. DNA replication in prokaryotes - so named because as replication proceeds around the single - circular chromosome - it takes on the appearnce of the Greek letter theta.






13. Photoreceptors in the retina of the eye that responds to bright light and provide color vision.






14. The fourth of meiosis I. Telophase I is identical to mitotic telophase - except that the number of chromosoms is now reduced by half. After this phase the cell is considered to be haploid. Note however - that the chromosomes are still replicated - an






15. High frequency of recombination bacterium An F+ bacterium that has the fertility factor integrated into its chromosome. When conjugation takes place - it is able to transfer not only the F factor - but also its genomic DNA.






16. The maximum amount of air that can be forcibly exhaled from the lungs after filling them to their maximum level - typically about 4500 mL






17. An organism (such as a fungus) that feeds of dead plants and animals.






18. The entropy (disorder) of the universe (or system) tends to increase.






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






20. The portion of the nephron tubule after the loop of Henle - but before teh collecting duct. Selective reabsorption and secretion occur here - most notably regulated reabsorption of water and sodium.






21. 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.






22. Haploid cells resulting from the first meiotic division of spermatogenesis. Secondary spermatocytes are ready to enter meiosis II.






23. An organs in the abdominal cavity with two roles. The first is an exocrine role: to produce digestive enzymes and bicarbonate - which are delivered to the small intestine via the pancreatic duct. The second is an endocrine role: to secrete insulin an






24. One of the four aromatic bases found in DNA and RNA. Cytosine is a pyrimidine; it pairs with guanine.






25. A cytoplasmic protein that binds to a stop codon where it appears in the A- site of the ribosome. Release factors modify the peptidyl transferase activity of the ribosome - such that a water molecule is added to the end of the completed protein. This






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






27. A region at the head of a sperm cell that contains digestive enzyems which - when released during the acrosome reaction - can facilitate penetration of the corona radiata of the egg - and subsequently - fertilization






28. A form of symbiosis in Which both organisms involved benefit from the association.






29. An enzyme that digests starch into disaccharides. Amylase is secreted by salivary glands and by the pancreas.






30. The flow of blood from the heart - through the body (not including the lungs) - and back to the heart.






31. A hydrophobic molecule - usually fomred from long hydrocarbon chains. The most common forms in which lipids are found in the body are as triglycerides (energy storage) - phospholipids (cell membranes) - and cholestero (cell membranes and steroid synt






32. An organelle surrounded by a double=membrane (two lipid bilayers) where ATP production takes place. The interior (matrix) is where PDC and the Krebs cycle occur - and the inner membrane contains the enzymes of the electron trasport chain and ATP synt






33. The third stage of cellular respiration - in which acetyl - CoA is combined with oxaloacetate to form citric acid. The citric acid is then decarboxylated twice and isomerized to recreate oxaloacetate. In the process - 3 molecules of NADH - 1 molecule






34. The enzymes that catalyzes the phosphorylation of glucose to form glucose -6- phosphate in the first step of glycolysis. This is one of the ain regulatory steps of this pathway. Hexokinase is feedback - inhibited by glucose -6- P.






35. Complementary DNA. DNA produced synthetically by reverse trascribing mRNA. Because of eukaryotic mRNA splicing - cDNA contains no inrons.






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






37. A set of veins that connect a capillary bed in the hypothalamus (the primary capillary plexus) with a capillary bed in the anterior pituitary gland (the secondary capillary bed). Releasing and inhibiting factors from the hypothalamus travel along the






38. The layer of connective tissue directly under the mucosa of an open body cavity.






39. Earlier embryonic ducts that can develop into femal internal genitalia in the absence of testosteron.






40. 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.






41. 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).






42. The depolarization of the egg plasma membrane upon fertilization - designed to prevent the entry of more than one sperm into the egg.






43. The portion of the cell membrane at the neuromusclar junction; essentially the postsynaptic membrane at the synapse.






44. A hormone produced and released by the kidney that stimulates the production of red blood cells by the bone marrow.






45. The percentage of wholeblood made up of erythrocytes The typical hematocrit value is between 40-45%.






46. Genes that are inherited only from the mother - such as mitochondrial genes (all organelles come only from the ovum).






47. The first phase of mitosis. During prophase the replicated chromosomes condense - the spindle is formed - and the nuclear envelope breaks apart into vessicles.






48. The connection of a mosin head group to an actin filament during muscle contraction (the sliding filament theory).






49. The monomer of a protein; amino acids hae an amio group on one end fo the molecule and a carboxylic acid group on the other - and of the of 2 different side chains.






50. The burrowing of a blastocyst (a developing embryo) into the endometrium of the uterus - typically occuring about a week after fertilizaiton.