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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 ductless gland that secretes a hormone into the blood






2. A toxin that secreted by a bacterium into its surrounding medium that help the bacterium compete with other species. Some exotoxins cause serious disease in humans (botulism - tetanus - diptheria - toxic shock syndrome).






3. A hormone released by teh G cells of the stomach in the presence of food. Gastrin promotes muscular activity of the stomach as well as secretion of hydrochloric acid - pepsinogen - and mucus.






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






5. The muscuar layer of the uterus. The myometrium is made of smooth muscles that retains its ability to divide in order to accomodate the massive size increases that occur during pregnancy. The myometrium is stimulated to contract during labor by the h






6. One of the four aromatic bases found in DNA. Thymine is a pyrimidine; it pairs with adenine.






7. A method of DNA protection utilized by prokaryotes in which their large circular chromosome is coiled upon itself.






8. The failure of two separate genes to boey the Law of Independent Assortment - as might occur if the genes were found close together on the same chromosome.






9. The reduction of pyruvate to either ethanol or lactate in order to regenerate NAD+ from NADH. Fermentation occurs in the absence of oxygen - and allow glycolysis to continue under those conditions.






10. MRNA that codes forsingle type of protein - such as is found in eukaryotic cells.






11. The first phase of meiosis II. Prophase II is identical to mitotic prophase - except that the number of chromosomes was reduced by half during meiosis I.






12. 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






13. The physical characterisitcs resulting from the genotype. Phenotypes are usually described as dominant or recessive.






14. The female primary sex organ. The ovary produces female gametes (ova) and secretes estrogen and progesterone.






15. The majority of the cells surrouding an oocyte in a follicle. Granulosa cells secrete estrogen during the follicular phase of the ovarian cycle (before ovulation).






16. A triat determined by a gen on either the X or Y chromosomes (the sex chromosomes).






17. The second phase of meiosis II. Metaphase II is identical to mitotic metaphase - except that the number of chromosomes was reduced by half during meiosis I.






18. Muscles located in between the ribs that play a role in ventilation.






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






20. The primary membrane lipid. Phospholipids consist of a glycerol molecule esterified to two fatty acid chains and a phosphate molecule. Additional - highly hyrohpilic groups are attached to the phosphate - making this molecule extremely amphipathic.






21. The portion of the nephron after the glomerulus and apsule; the region of the nephron where the filtrate is modified along its path to becoming urine.






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






23. The prokaryotic ribosome - binding site on mRNA - found 10 nucleotides 5' to the start codon.






24. A version of a gene. For example - the gene may be for eye color - and the allels include those for brown eyes - those for blu e eyes - those green eyes - etc. At most - dploid organsims can posses only two alleles for a given gene - one on each of t






25. A drop in blood pH due to hypoventilation (too little breathing) and a resulting accumulation of Co2.






26. 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






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






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






29. The primary female sex hormone. Estrogen stimulates the development of female secondary sex characteristics during puberty - maintains those characteristics during adulthood - stimulates the development of a new uterine lining after menstruation - an






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






31. The neurotransmitter used by the sympathetic division of the ANS at the postganglionic (organ - level ) synapse.






32. A prokaryotic enzyme used to twist teh single circular chromosome of prokaryotes upon itself to form supercois. Supercoiling helps to compact prokaryotic DNa and make it sturdier.






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






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






35. One of two large vessels (superior and inferior) that return deoxygenated blood to the right atrium of the heart.






36. A gene that has effects on several different characteristics.






37. A clear area in a lawn of bacteria. Plaques represent an area where bacteria are lysing (dying) and usually caused by a lytic virus.






38. A group of nucleotides that does not specify a particular amino acid - but instead serves to notify the ribosome that the protein being translated is complete. The stop codons are UAA - UGA - and UAG. They are also known as nonsense codons.






39. An organism that relies on a chemical source of energy (such as ATP) instead of light (which phototrophs).






40. Major Histocompatability complex - a set of proteins found on the plasma membranes of cells that help display antigen to T cells. MHC I is found on all cells and displays bits of proteins from within the cell; this allows T cells to monitor cell cont






41. A bacterial structure formed in unfavorable growth conditions. Endospores have very rough outer shells made of peptidoglycan and can survive harsh conditions. The bacterium inside the endospore is essentially dormant and can become active (called ger






42. A clear fluid the circulates around through the brain and spinal cord that helps to physially support teh brain and act as a shock absorber - and taht also exchanges nutrients and wastes with teh brain and spinal cord.






43. Also known as the cortical reaction - the slow block invovles an increase in intracellular [Ca2+] in the egg - which causes the release of cortical granules near the egg plasma membrane. This results in the hardening of the zona pellucida and its sep






44. One of the three primary (embryonic) germ layers formed during gastrulation. Endoderm ultimately forms internal structures - such as the inner lining of the GI tract and glandular organs.






45. A flexible piece of cartilage in the larynx that flips downward to seal teh trachea during swallowing.






46. The portion of the cardiac conduction system between the SA node and the AV node.






47. Myelinated axons






48. A structure made of two protein subunits and rRNA; this is the site of protein synthessis (translation) in a cell. Prokaryotic ribosomes (also known as 70S ribosomes) are smaller than eukaryotic ribosome (80S ribosomes). The S value refers to the sed






49. 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).






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