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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. The movement of a substance across a membane via pressure. In the kidney - filtration refers specifically to the movement of plasma across the capillary walls fo the glomerulus - into the capsule and tubule of the neprhon. Filtration at teh glomerulu
Neuron
Filtration
Peripheral membrane protein
G- protein linked receptor
2. The amount of blood returned to heart by the vena cavae.
Osteocyte
Conjugation
Epitope
Venous returns
3. The return of membrane potential to normal resting values after a depolarization of hyperpolarization.
Ejaculation
Telencephalon
Repolarization
Creatine Phosphate
4. An embryonic structure particularly important in egg - laying animals because it contains the yolk - the only source of nutrients for the embryo developing inside the egg. In humans - the yolk sac is very small (since mammals get their nutrients via
Hfr bacterium
Yolk sac
Activation energy (Ea)
Loose connective tissue
5. A form of genetic recombination in bacteria in which plasmid and/or genomic DNA is transferred from one bacterium to the toher through a conjugation bridge.
Bowman's capsule
Nondisjunction
Conjugation
Synapsis
6. An ion channel that is oepend or closed based on the electrical potential across the plasma membrane. Once opened - the channel allows ions to cross the membrane according to their concentration gradients. Examples are the Na+ and K+ voltage - gated
Pancreas
Aorta
Calmodulin
Voltage - gated ion channel
7. A type of synapse at which a chemical (a neurotransmitter) is released from teh axon of a neuron into the ysnaptic cleft where it binds to receptors on the next structure in sequence - either another neuron or an organ.
Fertilization
Replication
Chemical synapse
Secondary spermatocytes
8. One of several different nutrietns that must be consumed in the diet - and generally not synthesized in the body. Vitamins can be hdyrophobic (fat - solube) or hydrophilic (water - soluble).
Osteocyte
Somatic nervous system
Vitamin
Parasite
9. The division between neighboring cardiac muscle cells. Intercalcated discs include gap junctions - which allow the cells to function as a unit.
Intercalcated discs
Vital capacity
Effector organ
RNA polymerase
10. In skeletal and cardiac muscle tissue - a filament composed of bundles of myosin molecules. The myosin head groups attach to the thick filaments and pull the toward the center of the sarcomere during muscle contraction.
Active transport
Plasma
hick filament
Fluid mosaic model
11. The portion of the brain responsible for visual and auditory startle reflexes.
Midbrain
Cross bridge
Leak channel
Urinary sphincter
12. 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
Hemostasis
Polyspermy
Myosin light - chain kinase (MLCK)
Hardy- Weinberg law
13. 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
Posterior pituitary gland
Pulmonary artery
Pepsin
Operator
14. A non - protein - but organic - molecule (such as vitamin) that is covalently bound to an enzyme as part of the active site.
Seminiferous tubules
Peptidoglycan
Prosthetic group
Cofactor
15. A portion of DNA that codes for some product - usually a protein - including all regulatory sequences. Some genes code for rRNA and tRNA - which are not translated.
Peptidoglycan
Competitive inhibitor
Gene
Granulosa cells
16. A nonliving - intracellular parasite. Viruses are typically just pieces of nucleic aid surrounded by a protein coat.
Virus
Meiosis
Interstitial cell
Nodes of Ranvier
17. A molecule (usually a protein) capable of initiating an immune repsonse (antibody production).
Thymus
Golgi apparatus
H zone
Antigen (Ag)
18. The primary enzyme in peroxisomes; catalse catalyzes the hydrolysis of hydrogen peroxide (H2O2) into water and oxygen.
Osteocyte
Catalase
Collagen
Start site
19. A bacterium having a spiral shape (plural = spirochetes)
Epiglottis
Temporal summation
Spirochete
Linker DNA
20. A hormone tha tcontrols the release of another hormone.
Functional synctium
Tropic hormone
Bohr effect
Lag phase
21. 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
Pleiotropic gene
Endospore
Tropic hormone
Zona pellucida
22. The normal configuration of double - stranded DNA in which the 5' end of oen strand is paired with the 3' end of the other
Hypothalamus
Penetration
Prolactin
Antiparallel orientation
23. The hollow center of an osteon - also known as a Haversian canal. The central canal contains blood vessels - lymphatic vessels - lymphatic vessels - and nerves. Bone is laid down around the central canal in concentric rings called lamellae.
Hepatic portal vein
Exon
Central canal
Epithelial tissue
24. The resistance to blood flow in the systemic circulation. Peripheral resistance increases if arteries constrict (diameter decreases) - and an increase in peripheral resistance leads t o an increase in blood pressure.
Uniporter
Trophoblast
Peripheral resistance
Pore
25. Hardy crystals consisting of calcium and phosphate that form the bone matrix.
Small intestine
Placenta
Hydroxyapatite
Golgi apparatus
26. The fourth and final phase of meiosis II. Telophase II is identical to mitotic telophase - except that the number of chromosomes was reduced by half during meiosis. I.
Relication fork(s)
Telophase II
Perfusion
Penetration
27. Ribosomal RNA; the type of RNA that associates with ribosomal proteins to make a functional ribosome. It is thought that the rRNA has the peptidyl transferase activity.
Secondary spermatocytes
Na+/K+ ATPase
Synapse
rRNA
28. The sphincter that separates the final part of the small intestine (the ileum) from the fron part of the large intestine (the cecum). It is typically kept contracted (closed) so that chyme can remain in the small intestine as long as possible. The il
Ileocecal valve
Nodes of Ranvier
Common bile duct
Juxtaglomerular cells.
29. The valve that controls the release of feces from the recturm. It has an internal part made of smooth muscle (thus involuntary) and an external part made of skeletal muscle (thus voluntary).
Cytokinesis
Anal sphincter
Hair cells
Anterioir pituitary gland
30. Bacteria that have a thin peptidoglycan cell wall covered by an outer plasma membrane. They stain very lightly (pink) in Gram stain. Gram - negative bacteria are typically more resistant to antibiotics than Gram - positive bacteria.
Gram - negative bacteria
F1 generation
Diencephalon
Aminoacyl tRNA
31. A neuron with a single axon and multiple dendrites; the most common type of neuron in the nervous system.
Tropic hormone
Multipolar neuron
Gibbs free energy
Productive cycle
32. The force required to resist the movement of water by osmosis. Osmotic pressure is essentialy a measure of the concentration of a solution. A solution that is hyighly concnetrated has a strong tendency to draw water into itself - so the pressure requ
Ligament
Recessive
Osmotic pressure
Peptide bond
33. An **organic molecuel taht associates non - covalently with an enzyme - and that is required for the proper functioning of the enzyme.
NADH
Osmotic pressure
Coenzyme
Jejunum
34. The interior of a mitochondrion (the region bounded by the inner membrane). - The matrix is the site of action of pyruvate dehydroganse complex and the Krebs cycle.
I band
Gustatory receptors
Matrix
Pupil
35. The organ that carries out teh command sent along a particular motor neuron
Effector organ
Urinary sphincter
Purine bases
Outer ear
36. (1) The integration of input (EPSPs and IPSPs) from many presynaptic neruons by a single postsynaptic neuron - either temporaly or spatially. Summation of al input can either stimulate the postsynaptic neuron and possibly lead to an action potential
Antidiuretic hormone (ADH)
Codominance
Effector organ
Summation
37. Peptidyl - tRNA site; the stie on a ribosome where the growing peptide (attached to a tRNA) is found during translation.
P site
Dermis
Estrogen
Induction
38. The release of milk from the mammary glands via contraction of ducts within the glands. Contraction is stimulated by oxytocin - which is released from the posterior pituitary when the baby begins nursing.
Cardiac output
Milk letdown
Antiparallel orientation
Ligand
39. The phase of the cell cycle during which the genome is replicated.
Spatial summation
Coenzyme
S phase
Centriole
40. (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
Secretion
Oxaloacetate
Cardiac muscle
Cortisol
41. A fibrous protein found on the intracellular side of the plasma membrane (also associated with the Golgi complex) that helps invaginate the membrane. Typically cel surface receptors are associated with clathrin - coated pits at the plasma membrane bi
Distal convoluted tubule
Cochlea
Clathrin
Allosteric regulation
42. Early embryonic ducts that can develop into male internal genitalia under the proper stimulation (testosterone).
Cardiac output
Jejunum
Follicular phase
Wolffian ducts
43. Transfer RNA; the type of RNA that carries an amino acid from the cytoplasm to the ribosome for incorporation into a growing protein.
Blastocyst
tRNA
Noncompetitive inhibitor
Replication
44. The smallest (and final) fibers in the cardiac conduction system. The Purkinje fibers transmit the cardiac impulse to the ventricular muscle.
Bacteriophage
Melanin
Purkinje fibers
Labia
45. An organism that will use oxygen (aerobic metabolism) if it is available - and that can ferment (anaerobic metabolism) if it is not.
Renal absorption
Facultative anaerobe
Alimentary canal
Microvilli
46. The first branches of the trachea. There are two primary bronchi - one for each lung.
Facultative anaerobe
Pinocytosis
Hemoglobin
Primary bronchi
47. A protein embedded in the lipid bilayer of a cell. These are typicallly cell surface receptors - channels - or pumps.
Heterotroph
Liver
Adenine
Integral membrane protein
48. An amphipathic molecule secreted by cells in the alveoli (type 2 alveolar cells) tha reducs surface tension on the inside of the alveolar walls. This prevents the alveoli from collapsing upon exhale and sticking together - thus reducing the effort re
Synaptic cleft
Linker DNA
Inducible enzymes
urfactant
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.
Amino Acid
Osteocyte
Dynein
Spongy bone
50. A layer of connective tissue underneath the epidermis of the skin. The dermis contains blood vessels - lymphatic vessels - nerves - sensory receptors - and glands.
Dermis
Yolk sac
Transversion mutation
Elastin