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Test your basic knowledge |
MCAT Prep Biology
Start Test
Study First
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 neuron found completely within the central nervous system. Interneous typically connect sensory and motor neurons - especially in reflex arcs.
Cholecystokinin (CCK)
Nephron
Interneuron
Semen
2. The primary enzyme in peroxisomes; catalse catalyzes the hydrolysis of hydrogen peroxide (H2O2) into water and oxygen.
Stop codon
Insulin
Catalase
Homologous chromosomes
3. A molecule (usually a protein) capable of initiating an immune repsonse (antibody production).
Ceruminous gland
Ligand
Antigen (Ag)
Operon
4. A haploid but immature cell resulting from the second meiotic division f spermatogenesis. Spermatids undergo significant physical changes to become mature sperm (spermatozoa).
Spermatid
Synaptic cleft
Desmosome
Osmosis
5. An enzyme secreted by the juxtaglomerular cells when blood pressure decreases. Renin onverts angiotensinogen to angiotensin I.
Peristalsis
Oval window
Transmembrane domain
Renin
6. Toward the 5' end of an Rna transcript (the 5' end of the DNA coding strand). The promoter and start sites are upstream.
Anal sphincter
Collecting duct
Upsteam
Acetylcholine (Ach)
7. The membrane that separates the middle ear from the inner ear.
Nucleus
Diastolic pressure
Sarcoplasmic reticulum
Oval window
8. A point mutation in which a pyrimidine is substitued for a purine - or vice versa.
Common bile duct
Transversion mutation
Pulmonary edema
B cell
9. The principal glucocorticoid secreted from teh adrenal cortex. This steroid hormone is released ruing stress - causing increased blood glucose levels and reducing inflammation. The latter effect has led to a clinical use of cortisol as an anti - infl
DNA polymerase
Pulmonary edema
Cortisol
Diaphysis
10. 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
Melanin
Centromere
Glomerulus
Allele
11. An enzyme inhibitor that binds at a site other than the active sit of an enzyme (binds at an allosteric site). THis changes the three - dimensional shape of the enzyme such that it can no longer catalyze the reaction
Baroreceptor
Leak channel
Stomach
Noncompetitive inhibitor
12. A junction between cells - consisting of a protein channel called a connexon on each of the two cells that connect to form a single channel between teh cytoplasms of both cells. Gap junctions allow small molecules to flow between teh cells - and are
Cecum
Obligate aerobe
Gap junction
Law of Segregation
13. The maintenance of relatively constant internal conditions (such as temperature - pressure - ion balance - pH - etc.) regardless of external conditions.
Homeostasis
Disaccharide
Catalase
Enterokinase
14. The second most common of the five classes of leukocytes. Lymphocytes are involved in specific immunity and include two cell types - B- cells and T cells. B- cells produce and secrete antibodies and T- cells are invovled in cellular immunity.
Lymphocyte
Channel protein
Tonsils
Shine - Dalgarno sequence
15. One of the four aromatic bases found in DNA. Thymine is a pyrimidine; it pairs with adenine.
Thymine
Nucleotide
tRNA loading
Sarcolemma
16. The energy in a system that can be used to drive chemical reactions. If the change in free energy of a reaction (Delta G - the free energy of the products minus the free energy of the energy of the reactants) is negative - the reaction will occur spo
Gibbs free energy
Vena cava
Bipolar neuron
Differentiation
17. A structure composed of a ring of nine microtube triplets - found in pairs in the MTOC (microtubule organizing center) of a cell. The centrioles duplicate during the cell division - and serve as the organizing center for the mitotic spindle.
Centriole
Polyspermy
Fermentation
Atrioventricular bundle (AV) bundle
18. Gaps in the myelin sheath of the axons of peripheral neruons. Action potentials can 'hump' from node to node - thus increasing the speed of conduction (saltatory conduction).
Stop codon
Operator
Nodes of Ranvier
Urethra
19. Something that works together with another thing to augment the the second thing's activity. For example - a uscle that assists another muslce is said to be a syngergist. An enzyme that helps another enzyme is a synergist.
Luteal phase
yngergist
Pleura
Hypodermis
20. 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] -
Erythrocyte
Aminoacyl tRNA
Innate immunity
Nondisjunction
21. A protein hormone secreted by sustenacular cells of the testes that acts to inhibit the release of FSH and LH from the anterior pituitary.
Inhibin
hnRNA
Luteinizing Hormone (LH)
Common bile duct
22. A gene appearing in a single copy in diploid organisms - e.g. X- linked genes in human males.
cDNA
Hemizygous gene
Meninges
Duodenum
23. The process of breaking down large molecules into smaller precursors - e.g. digesion of starch into glucose.
Catabolism
Ion channel
Avascular
Nucleoside
24. The specific site on an antigenic molecule that binds to a T cell receptor or to an antibody.
Hypothalamus
Mitochondrion
Epitope
Autotroph
25. An organism that can only survive in the absence of oxygen (anaerobic metabolism); oxygen is toxic to obligate anaerobes.
Obligate anaerobe
Retina
Autosome
Anaphase
26. The birth canal; the stretchy - muscular passageway through which a baby exits the uterus during childbirth.
Relative refractory period
Lytic cycle
Vagina
Tetrad
27. Aromatic bases found in DNa and RNA that have a single - ring structure. They include cytosine - thymine - and uracil.
Pyrimidine bases
Connective tissue
Depolarization
5' cap
28. The secon phase of mitosis. During metaphase chromosomes align at the center of the ell (the metaphase plate).
Metaphase
Phosphofructokinase
Posterior pituitary gland
Endometrium
29. Pain receptors. Nociceptors are found everywhere in the body except for the brain.
Metaphase
Nociceptors
Syncytium
Histones
30. A hormone made of amino acids (in some cases just a single - modified amino acid). Peptide hormones are generally hydrophilic and cannot cross the plasma membranes of cells - thus receptor for peptide hormones must be found on the cell surface. An ex
Intercostal muscles
Peptide hormone
Aldosterone
Cones
31. Also called negative feedback - the inhibition of an early step in a series of events by the product of a later step in the series. This has the effect of stopping the series of events when the products are plentiful and the series is unnecesseary. F
Lipoprotein
Feedback inhibition
Saprophyte
Peristalsis
32. A layer of cells surroudning the granulosa cells of the follicles in an ovary. Thecal cells help produce the estrogen secreted from the follicle during the first phase of the ovarian cycle.
Thecal cells
Gray matter
Glomerulus
Telophase
33. Sensory receptors found in the inner ear. Cochlear hair cells respond to vibration in the cochlea caused by sound waves and vestibular hair cells respond to changes in position and acceleration (used for balance).
Urethra
Accessory organs
Saltatory conduction
Hair cells
34. The first branches of the trachea. There are two primary bronchi - one for each lung.
Envelope
Primary bronchi
Expiration
Ciliary muscles
35. A protein - based substance secreted by cells of the epiderms as they migrate outward. The keratin makes the cells tougher (better able to withstand abrasion) and helps make the skin waterproof.
Large intestine
Platelets
Integral membrane protein
Keratin
36. A hole in the center of the iris of the eye that allows light to enter the eyeball. The diameter of pupil is controlled by the iris in response to the brightness of the light.
Myofiber
Pupil
Repolarization
Clathrin
37. Myelinated axons
White matter
A site
Release factor
Activation energy (Ea)
38. The portion of theforebrain that includes the thalamus and hypothalamus.
Diaphysis
Symporter
Fetal stage
Diencephalon
39. 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.
Vein
Nephron
Juxtaglomerular cells.
Sclera
40. A carrier protein that transports two molecules across the plasma membrane in the same direction. For example - the Na+- glucose cotransporter in intestinal cells is a symporter.
Endoderm
Chorion
Symporter
Sertolli cells
41. Diploid cells resulting from the activation of anoogoium; primary oocytes are ready to enter meiosis I. remember: cyte means ready to undergo meiosi
Primary oocytes
Heterotroph
Lawn
Portal systems
42. Very small tube or channel - such as is found between lacunae (connecting them together) in compact bone.
Thin filament
Anaphase
Canaliculus
Pleiotropic gene
43. An enzyme whose transcription can be stimulated by an abundance of its substrate (as opposed to repressible enzyme). Usually in catabolism.
Rule of addition
Pore
Flagella
Inducible enzymes
44. The outer layer of smooth muscle in the wall of the digestive tract. When the longitudinal muscle contracts the tube shortens.
Longitudinal muscle
Epitope
Purkinje fibers
Afferent neuron
45. Earlier embryonic ducts that can develop into femal internal genitalia in the absence of testosteron.
Adenohypophis
Telophase I
Sympathic nervous system
Mullerian ducts
46. An **organic molecuel taht associates non - covalently with an enzyme - and that is required for the proper functioning of the enzyme.
Coenzyme
Nephron
Monosaccharide
Frameshift mutation
47. The period of time following an action potential when it is possible - but difficult - for the neuron to fire a second action potential due to the fact that membrane is further from theshold potential (hyperpolarized).
Length - tension relationship
Relative refractory period
Hepatic portal vein
Desmosome
48. The maximal volume of air that the lungs can contain. Total lung capacity is the sum of the vital capacity and the residual volume - and is typically about 6000 mL (6L).
Pancreas
Lacteals
Total lung capacity
Anaphase I
49. 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.
Universal donor
Cholecystokinin (CCK)
Renal absorption
Nucleotide
50. A point mutation in which a condon that specifies an amino acid is mutated into a stop (nonsense) codon.
Avascular
Nonsense mutation
Length - tension relationship
Spongy bone