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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 period of time following an action potential during which no additional action potential can be evoked regardless of the level of stimulation. (usually because Na+ channel closed whle K+ efflux)
Hypophysis
Metaphase
Absolute refractory period
Totipotent
2. Complementary DNA. DNA produced synthetically by reverse trascribing mRNA. Because of eukaryotic mRNA splicing - cDNA contains no inrons.
Histones
cDNA
Endometrial cycle
Innate immunity
3. The final portion of the large intestine.
Gonadotropin releasing hormone (GnRH
Supercoiling
Rectum
Thecal cells
4. A contractile protein connecting microtubules in the '9+2- arrangement of cilia and eukaryotic flagella. The contraction of dynein produces the characteristic movement of these structures.
Epitope
Dynein
Pacemaker potential
Sarcoplasmic reticulum
5. An ion channel that is constitutively open - allowing the movement of teh ion across the plasma membrane according to its concentration gradient.
Leak channel
Transduction
Law of Segregation
Gustatory receptors
6. A string of several hundred adenine nucletodies added to the 3' end of the eukaryotic mRNA.
Poly- A tail
Osteoblast
Matrix
Gastrulation
7. The location on a chromosome where transcription begins.
Hardy- Weinberg law
Artery
Endocrine system
Start site
8. The pituitary gland.
Spermatogenesis
Nucleus
Hypophysis
Afferent arteriole
9. The darkly pigmented middle layer of the eyeball - found between teh sclera (outer layer) and the retina (inner layer).
Choroid
Cardiac muscle
Endocrine gland
Bulbourethral galnds
10. The cytoskeleton filaments with the smallest diameter. Microfilaments are composed of the contractile protein actin. They are dynamic filaments - constantly beig made and broken down as needed - and are responsible for events such as pseudopod format
Microfilament
Centromere
Population
Autoimmune reaction
11. Formerly called the cardiac sphincter - this sphincter marks the entrance to the stomach. Its function is to prevent reflux of acid stomach contents into the esophagus; note that it does **not regulate entry into the stomach.
Lower esophageal sphincter
Systemic circulation
Trophoblast
Tetanus
12. The largest of the cytoplasmic filaments. Microtubules are composed of two types of protein - alpha tubulin and beta tubulin. They are dynamic fibers - constantly being built up and broken down - according to cellular needs. Microtubules form the mit
Proximal convoluted tubuel
Capilary
Codominance
Microtubule
13. A strong band of connective tissue that connets bones to one another.
Sarcoplasmic reticulum
Hexokinase
Ligament
Synaptic cleft
14. 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
Action potential
Epithelial tissue
Exclusion
Graafian follicle
15. Peptidyl - tRNA site; the stie on a ribosome where the growing peptide (attached to a tRNA) is found during translation.
Silent mutation
Mutualism
P site
Capsid
16. The duplication of DNA
Prophase II
Primary oocytes
Nephron
Replication
17. The cells of the distal tubule at the juxtaglomerular apparatus. They are receptors that monitor filtrate osmolarity as a means of regulatin filtration rate. If a drop is osmolarity is sensed - the macula densa dilates the afferent arteriole (to incr
Growth hormone
Antiparallel orientation
Macula densa
Metaphase
18. The process by which neighboring cells can influence the determination (and subsequent differentiation) of a cell.
Fermentation
Induction
Thyroxine
Diastolic pressure
19. A hormone produced and released by the kidney that stimulates the production of red blood cells by the bone marrow.
Erythropoietin
Lipid
Resolution
Telophase I
20. A gland that secretes a waxy product - found in the external ear canal.
Auditory tube
Placental villi
Ceruminous gland
Telomere
21. A point mutation in which a condon that specifies an amino acid is mutated into a stop (nonsense) codon.
Second Law of Thermodynamics
Cell surface receptor
Nonsense mutation
Lumen
22. A life cycle of animal viruses in which the mature viral particles bud from the host cell - acquiring an envelope (a coating of lipid bilayer) in the process.
Anal sphincter
Productive cycle
Gastrulation
Operator
23. General - non - specific protection to the body - including the skin (barrier) - gastric acid - phagocytes - lysozyme - and complement.
Exon
Innate immunity
Glomerulus
Metaphase II
24. An enzyme that lyses bacterial cell walls. Lysozyme is produced in the end stages of the lytic cycle so that new viral particles can escape their hosst; it is also found in human tears and human saliva.
Secretin
Adenine
Lysozyme
Uterine tubes
25. A chemical derived from vitamin A found in the pigment proteins of the rod photoreceptors of the retina. Retinal changes conformation when it absorbs light - triggering a series of reactions that ultimately result in an action potential being sent to
Retinal
Telophase II
Cones
Binary fission
26. A vein connecting the capillary bed of the intestines with the capillary bed of the liver. This allows amino acids and gluocse absorbed from the intestines to be delivered first to the liver for processing before being transported throughout the circ
Seminal vesicles
Metaphase I
Start site
Hepatic portal vein
27. Specif ic defense of the body by antibodies - secreted into the blood by B- cells.
Humoral immunity
Aqueous humor
Portal systems
Ligament
28. Zygot - derived projections that extend into the endometrium of the uterus during pregnancy. Fetal capillaries grow into the placental villi - which are surrounded by a pool of maternal blood. THis facilitates nutrient and gas exchange between the mo
Placental villi
Nondisjunction
Androgens
Coenzyme
29. The opening to the uterus The ervix is typically plugged with a sticky acidic mucus during non - fertile times (to form a barrier against the entry of pathogens) - however during ovulation the mucus becomes more watery and alkaline to facilitate sper
T tubules
Acetylcholinesterase (AChE)
Cervix
Fibrinogen
30. The specialization of cell types - especially during the embryonic and fetal development.
Theta replication
Differentiation
Serum
Testes
31. A protein that is associated with the plasma membrane of a cell - but that is not embedded in the lipid bilayer. Peripheral proteins typically associate with embedded proteins through hydrogen bonding or electrostatic interactions.
hnRNA
Endometrium
Anaphase
Peripheral membrane protein
32. The rapid mitotic division of a zygot that being within 24-36 hours after fertilization
Eukaryotic
Endotoxin
Cleavage
Adipocyte
33. Microscopic outward folds of the cells lining the small intestine; microvilli serve to increase the surface area of the small intestine for absorption.
Transcription
Phospholipid
Longitudinal muscle
Microvilli
34. A diploid cell that can undergo mitosis to form more spermatogonium - and can also be triggered to undergo meiosis to form sperm.
Spermatogonium
Residual volume
Bronchioles
Upsteam
35. The period of exponential growth of bacterial population.
Chorion
Phagocytosis
Log phase
Sphygmomanometer
36. The movement of air into the respiratory tract. Inspiration is an active process - requiring contraction of the diaphragm.
Auxotroph
Inspiration
Luteinizing Hormone (LH)
Primary oocytes
37. Active transport that relies directly on the hydrolysis of ATP.
FSH
Uracil
Primary active transport
Large intestine
38. A small gland encircling the male urethra just inferior to the bladder (only reproductive structure not paired). Its secretion contain nutrients and enzymes and account for approximately 35% of the ejaculate volume.
Trypsin
Plaque
Vestibular glands
Prostate
39. A layer of collagen fibers that separates epithelial tissue from connective tisse (example of epithelial cells in digestive tract) - they are actual connective tissue.
Longitudinal muscle
Basement membrane
Stomach
Organ of Corti
40. (1) In the GI tract - organs that play a role in digestion but not directly part of the alimentary canal. These include the liver - the gallbladder - the pancreas - adn the salivary glands.
Wolffian ducts
Telophase II
Microtubule
Accessory organs
41. A looser - more porous type of bone tissue found at the inner core of the epiphyses in long bones and all other bone types. Spongy gone is filed with red bone marrow - important in blood cell formation.
Androgens
Spongy bone
Metaphase
Actin
42. A cyclic version of adenosine monophosphate - where the phosphate is esterified to both the 5' and 3' carbons - forming a ring. Cyclic AMP is an important intracellular signaling moelcule - often called the 'second messenger.' It serves to activate c
Cyclic AMP (cAMP)
Semen
Ovulation
Yolk sac
43. A type of cell division (in diploid cells) that reduces the number of chromosomes by half. Meiosis usualy produces haploid gametes in organisms that undergo sexual reproduction. It consists of a single interphase (G1 - S - and G2) followed by two set
Operon
Meiosis
Hemizygous gene
Fluid mosaic model
44. A four - carbon molecule that binds with the two - carbon acetyl unit of acetyl - CoA to form citric acid in the first step of the Krebs cycle.
5' cap
Mucosa
Oxaloacetate
Chemical synapse
45. 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
Chief cells
Release factor
Log phase
Anterioir pituitary gland
46. The structure in the cochlea of the inner ear made up of the basilar membrane - the auditory hair cells - and the tectorial membrane. The Organ of Corti is the site where auditory sensation is detected and transduced to action potentials.
Steroid hormone
Tendon
Epiphysis
Organ of Corti
47. The secretion of a cellular product to the extracellular medium through a secretory vesicle.
Melanin
Thymine
Exocytosis
Mitochondrion
48. The portion of the cell membrane at the neuromusclar junction; essentially the postsynaptic membrane at the synapse.
Goblet cells
Receptor - mediated endocytosis
Totipotent
Motor end plate
49. 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
Autosome
RNA polymerase
T cell
Labor contractions
50. A lipid bilayer that surrounds the capsid of an animal virus. the envelope is acquired as teh virus buds out through the plasma membrane of its host cell. Not all annimal viruses possess and envelope.
Uracil
Enterogasterone
Envelope
Smooth muscle