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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 peptide hormone produced and secreted by the Beta cells of the pancreas. Insulin targets cells in the body - especially the liver and muscle - and allows them to take glucose out of gthe blood (thus lowering blood glucose levels).
Canaliculus
Lymphocyte
Insulin
Keratin
2. The largest bundle of white matter (axons) connecting th two cerebral hemispheres.
Afferent arteriole
FSH
Telophase II
Corpus callosum
3. A virus that infects a bacterium.
Afferent neuron
Obligate anaerobe
Bacteriophage
Hypothalamus
4. A pigment produced by melanocytes in teh bottom cell layer of the epidermis. Melanin production is increased on sun exposure and helps prevent cllular damage due to UV radiation.
Tropomyosin
Tolerant anaerobe
Melanin
Downstream
5. A blood clot that forms in an unbrokened blood vessel. Thrombi are dangerous they can break free and begin travelin in the bloodstream (become an embolus). Emboli ultimately become stuck in a small vessel and prevent adequate blood delivery to tissue
Thrombus
Clathrin
Oxytocin
Krebs cycle
6. A hormone produced from vitamin D that acts in essentially the same manner as parathyroid hormone.
Calcitriol
Erythropoietin
Conjugation
Photoreceptor
7. An asexual method of bacterial reproduction that serves only to increase the size of the population; ther is no introduciton of gnetic diversity. THe bacterium simply grows in size until it has doubled its cellular components - then it replicates its
Repressor
Binary fission
Microvilli
Adenine
8. A dense - hard type of bone constructed from osteons (at the microscopic level). Compact bone forms the diaphysis of the the long bones - and the outer shell of the epiphyses and all other bones.
Pancreatic duct
Lymph node
Second Law of Thermodynamics
Compact bone
9. The flow of blood from the heart - through the lungs - and back to the heart.
Macula densa
Umbilical cord
Proximal convoluted tubuel
Pulmonary circulation
10. A constant input to the arteries that keeps them somewhat constricted to maintain a basal level of blood pressure.
Adrenergic tone
Ileocecal valve
Oxaloacetate
Relication fork(s)
11. The reduced from (carries electrons) of FAD (flavin adenine dinucleotide). this is the other main electron carrier in cellular respiration (NADH is the most common).
Chemotaxis
FADH2
Internodal tract
Synaptic cleft
12. A group of three nucleotides taht is specific for a particular amino acid - or that specifies 'stop translating'
Supercoiling
Histones
Codon
Nuclear envelope
13. A precursor cell that undergoes mitosis during fetal development to produce more oogonium. These cells are then activated to produce primary oocytes - which remain dormant until stimulated to undergo meiosis I during some future menstrual cycle.
Repressor
Chylomicron
Rough endoplasmic reticulum
Oogonium
14. 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
Diencephalon
RNA polymerase
Progesterone
Hardy- Weinberg law
15. Produced in muscle cells from the reduction of pyruvate (under anaerobic conditions) to regenerate NAD+ so that glycolysis can continue. A rise in lactic acid usually accompanies an increase in physical activity.
Systolic pressure
Hemostasis
Maternal inheritance
Lactic acid
16. A function in the reproductive system - controlled by the parasympathetic nervous system - that includes erection (via dilation of erectile arteries) and lubrication.
Chitin
Connective tissue
Haploid organism
Arousal
17. 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.
Exon
Dorsal root ganglion
Pilus
Coenzyme
18. The maintenance of relatively constant internal conditions (such as temperature - pressure - ion balance - pH - etc.) regardless of external conditions.
Tonsils
Homeostasis
Theta replication
Thecal cells
19. The first part of the large intestine.
Cecum
Cooperativity
Mutualism
Brush border enzymes
20. Aromatic bases found in DNa and RNA that have a single - ring structure. They include cytosine - thymine - and uracil.
Serum
Metaphase
Tonsils
Pyrimidine bases
21. A structure near the middle of eukaryotic chromosomes to which the fibers of the mitotic spindle attach during cell division.
Inducible enzymes
Sinoatrial (SA) node
Ossicles
Centromere
22. A motor neuron and all the all the skeletal muscle cells it innervates. Large motor units are typically found in large muscles (e.g. - the thighs and buttocks) and produce fross movements. Small motor untis are found in smaller muscles (e.g. the rect
Eukaryotic
Graafian follicle
Excitation - contraction coupling
Motor unit
23. A thick muscular tube that connects the epididymis of the testes to the urethra. Muscular contractions of the vas deferns during ejaculation ehp propel the sperm outward. Severing of the vas deferens (vasectomy) results in sterility of the male.
Prosthetic group
Vas deferens
Nucleolus
Inspiration
24. A pair of replicated homologous chromosomes. Tetrads form during prophase I of meiosis so that homologous chromosomes can exchange DNA in a process known as 'crossing over.'
Fibroblast
Tetrad
Systolic pressure
Gap junction
25. The second major node of the cardiac conduction system (after the SA node). The cardiac impulse is delayed slightly at teh AV node - allowing the ventricles to contract just after the atria contract.
Purkinje fibers
Hfr bacterium
Activation energy (Ea)
Atrioventricular (AV) node
26. 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.
Substrate(s)
Exocytosis
Myofibril
Hemoglobin
27. A triat determined by a gen on either the X or Y chromosomes (the sex chromosomes).
Sex- linked rait
Feedback inhibition
Penetration
Lymphokine
28. A thin - watery fluid found in teh anterior segment of the eye (between the lens and the cornea). THe aqueous humor is constantly produced and drained - adn helps to bring nutrients to the lesn and corena - as well as to remove metabolic wastes
Oxaloacetate
Coenzyme
Aqueous humor
Myosin light - chain kinase (MLCK)
29. 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.
Mutualism
Symporter
Ligase
Simple diffsuion
30. To attach oxygen - to remove hydrogen - or to remove electrons from a molecule.
Synapse
Oxidation
Osmosis
Lymphatic system
31. Mal sex hormones. Testosteron is the primary androgen.
Obligate anaerobe
Fibroblast
Chemoreceptor
Androgens
32. The inner region of an organ - e.g. - the renal medulla - the ovarian medulla - and the adrenal medulla - etc.
Release factor
Medulla
Desmosome
Edema
33. An intracellular chemical signal (such as cAMP ) that relays instructions from the cell surface to enzymes in the cytosol.
Aqueous humor
Pulmonary artery
Second messenger
Binary fission
34. The monomer of a carbohydrate. Monosaccharides have the general chemical formula CnH2nOn - and common monosaccharides include glucose - fructose - galactose - and ribose.
Gallbladder
Endocytosis
Monosaccharide
Retrovirus
35. An **organic molecuel taht associates non - covalently with an enzyme - and that is required for the proper functioning of the enzyme.
Prolactin
Coenzyme
Pyrimidine bases
Conjugation
36. A hormone secreted by the samll intestine (duodenum) in response to the presence of fats. It promotes release of bile from the gallbladder and pancreatic juice from the pancreas - and reduces stomach motility.
Cholecystokinin (CCK)
Nucleus
Expiration
Simple diffsuion
37. 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
Gap junction
Gustatory receptors
Antigen presenting cell
Poycistronic mRNA
38. A steroid hormone produced by the corpus luteum in the ovary during the second half of the menstrual cycle Progesterone maintains and enhances the uterine lining for the possible implantation of a fertilized ovum. It is the primary hormone secreted d
DNA polymerase
Organ of Corti
Lysogenic cycle
Progesterone
39. Inhibitory postsynaptic potential; a slight hyperpolarization of the postysynaptic cell - moving the membrane potential of that cell further from threshold.
Iris
Aqueous humor
Transversion mutation
IPSP
40. A chemical secreted by a T cell (usually the helper Ts) that stimulates activation and proliferation of other immune system cells.
Serum
Lymphokine
Trypsin
Phenotype
41. The third phase of meiosis I. During anaphase I the rplicated homologous chromosomes are separated (the tetrad is split) and pulled to opposite sides of the cell.
A site
Disaccharide
Anaphase I
Diastolic pressure
42. The unit of combact bone - also called a Haversian system. Osteons are essentially long cylinders of bone; the hollow center is called the central canal - and is where blood vessels - nervs - and lymphatic vessels are found. Compact bone is laid down
Osteon
Vaccination
Milk letdown
Pancreas
43. A highly specific cellular uptake mechanism. The molecule to be taken up must bind to cell surface receptor found in a clathrin - coated pit.
Noncompetitive inhibitor
Receptor - mediated endocytosis
Basement membrane
Plasmid
44. The oxidation of high - energy electron carriers (NADH and FADH2) coupled to the phosphorylation of ADP - producing ATP. In eukaryotes - oxidative phosphorylation occurs in the mitochondira.
Cerebellum
Oxidative phosphorylation
Rectum
tRNA
45. A localized change in a neruon's or musce cell's membrane potential that can propogate itself away from its point of origin. Action potentials are an all - or - none process mediated by the opening of voltage - gated Na+ and K+ channels when the memb
Bowman's capsule
Purkinje fibers
Action potential
Histones
46. The division of the periperal nervsous system that innervates and cotnrols the visceral organs (everything but the skeletal muscles). It is also knowns as the involuntary nervous system and an be subdivided into the sympathetic and parasympathetic di
Endocrine system
Baroreceptor
Autonomic nervous system (ANS)
Antiporter
47. The law of conservation of energy; the energy of the universe is constant - thus if the energy of a system increases - the energy of its surroundings must decrease - and vice versa.
Urethra
Inducible enzymes
First law of Thermodynamics
Outer ear
48. A projection of the cell body of a neuron that recieves a nerve impulse form a different neuron and send the impulse to the cell body. Neurons can have one or several dendrites!
Ligase
Endocrine system
Dendrite
Saltatory conduction
49. A series of enzyme complexes found along the inner mitochondrial membrane. NADH and FADH2 are oxidized by tehse enzymes; the electrons are shuttled down the chain and are ultimately passed to oxygen and to produce water. The electron energy is used t
Cilia
Leak channel
Growth hormone
Electron transport chain
50. 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.
Diencephalon
Autoimmune reaction
Fermentation
Vagal tone