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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 portion of the cell membrane at the neuromusclar junction; essentially the postsynaptic membrane at the synapse.
Motor end plate
Stomach
Coccus
Endosymbitoic theory
2. The subdivision of the nervous system consisting of the brain and spinal cord.
Central Nervous System
Peripheral chemoreceptors
Fimbriae
Channel protein
3. 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
Urinary sphincter
Restriction endonuclease
Phosphofructokinase
Myometrium
4. 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.
Ciliary muscles
Vas deferens
Cholesterol
Proprioreceptor
5. The neurotransmitter used by the sympathetic division of the ANS at the postganglionic (organ - level ) synapse.
Norepinephrine
MHC
Macrophage
Hemophilia
6. The prokaryotic ribosome - binding site on mRNA - found 10 nucleotides 5' to the start codon.
Hardy- Weinberg law
Synaptic cleft
Gray matter
Shine - Dalgarno sequence
7. Plasma with the clotting factors removed. Serum is often used in diagnostic tests because it does not clot.
RNA dependent RNA polymerase
Serum
Peptide bond
Amino acid acceptor site
8. A situation in which the expression of one gene prevents expression of all allelic forms of another gene - e.g. - the gene for male pattern baldness is epistatic to the hair color gene.
Gap junction
Glucagon
Periplasmic space
Epistasis
9. (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
Summation
Pinocytosis
Chorion
Parasite
10. A neuron that carries information (action potentials) away from the central nervous system; a motor neuron.
Meiosis
Medulla
Efferent neuron
Complement system
11. The process by which neighboring cells can influence the determination (and subsequent differentiation) of a cell.
Chorion
Gap phase
Induction
Rods
12. Pain receptors. Nociceptors are found everywhere in the body except for the brain.
Thrombus
Lag phase
Nociceptors
Fascicle
13. Paired masses of lymphatic tissue near the back of the throat that help trap inhaled or swallowed pathogens.
Tonsils
Secondary immune response
P site
Cytokinesis
14. The product of glycolysis; 2 pyruvic acid (pyruvate) molecules are produced from a single glucose molecule. In the absence of oxygen - pyruvic acid undergoes fermentation and is reduced to either lactic acid or ethanol; in the presence of oxygen - py
Epithelial tissue
Phospholipid
Pyruvic acid
Obligate aerobe
15. One of the four aromatic bases found in DNA and RNA; also a component of ATP - NADH - and FADH2. Adenine is apurine; it pairs with thymine (in DNA) and with uracil (in RNA)
Epiglottis
Erythropoietin
Adenine
Log phase
16. An enzyme inhibitor that competes with substrate for binding at the active site of teh enzyme. When the inhibitor is bound - no product can be made.
Lymphatic system
Pyruvate dehydrogenase complex
Neurotransmitter
Competitive inhibitor
17. The layer of granulosa cells taht surround an oocyte after is has been ovulated.
Corona radiata
Norepinephrine
Hypophysis
Pore
18. An **organic molecuel taht associates non - covalently with an enzyme - and that is required for the proper functioning of the enzyme.
Pulmonary edema
Somatic nervous system
Facultative anaerobe
Coenzyme
19. One of the two peripheral nervous system supporting (glial) cells. Schwann cells from he myelin sheath on axons of peripheral neurons.
Sclera
Cardiac muscle
Myosin
Schwann cell
20. A tropic hormone produced by the anterior pituitary gland that targets the thyroid gland - stimulating it to produce and release thyroid hormone.
Cardiac output
Catabolism
Thyroid stimulating hormone (TSH)
Poycistronic mRNA
21. The period of time during which the ventricles of the heart are contracted.
Systolic pressure
A band
Lymphokine
Systole
22. The portion of an integral membrane protein that passes through the lipid bilayer.
Pepsin
Ejaculation
Transmembrane domain
Inspiration
23. The valve that regulates the passage of chyme from the stomach into the small intestine.
Chemical synapse
Nondisjunction
Receptor - mediated endocytosis
Pyloric sphincter
24. A hormone derived from cholesterol. Steroids are generally hydrophobic and can easily cross the plasma membrane of cells - thus receptors for steroids are found intracellularly. Once this steroid binds to its receptor - the receptor - steroid complex
Steroid hormone
A band
Heterotroph
Tight junction
25. The first substrate in teh Krebs cycle - produced primarily from the oxidation of pyruvate by the pyruvate dehydrogenase complex - however acetyl - CoA is also produced during fatty acid oxidation and protein catabolism.
Activation energy (Ea)
Translation
Acetyl - CoA
Iris
26. MRna that codes for several different proteins by utliizing different reading frames - nested genets - etc. Polycistronic mRNa is a characteristic of prokaryotes.
Poycistronic mRNA
Symporter
Population
Inhibin
27. 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
Aldosterone
Gibbs free energy
Peptidoglycan
Lumen
28. The movement of a particle (the solute) in a solution from its region of high concentration to its region of low concentration ( or down it concentration gradient).
Supercoiling
Progesterone
Menstruation
Diffusion
29. A phase in the cycle between mitosis and S phase (G1) or between S phase and mitosis (G2). During gap phases the cell undergoes normal activity and growth; G1 may include preparation for DNA replication and G2 includes preparation for mitosis. Note t
Inspiration
Channel protein
Gap phase
Hypothalamic - pituitary portal system
30. The combination of alleles of an organism carries. In a homozygous genotype - both alleles are the same - whereas in a heterozygous gentorype the alleles are different.
Genotype
Repolarization
Tendon
Endometrial cycle
31. The division of the inner cell mass of a blastocyst (developing embryo) into the three primary germ layers. Gastrulation occurs during weeks 2-4 of gestation.
Osteon
Gastrulation
Spatial summation
Homozygous
32. Specif ic defense of the body by antibodies - secreted into the blood by B- cells.
Heterochromatin
Acetyl - CoA
Humoral immunity
Exocytosis
33. The white portion of teh tough outer layer of the eyeball
F (fertility) factor
Sclera
Secondary oocyte
Haploid organism
34. An enzyme whose transcription can be stimulated by an abundance of its substrate (as opposed to repressible enzyme). Usually in catabolism.
Inducible enzymes
Nucleus
Cristae
Fermentation
35. A drop in blood pH due to hypoventilation (too little breathing) and a resulting accumulation of Co2.
Saprophyte
Internodal tract
Respiratory acidosis
Hemoglobin
36. Identical copies of a chromosome - produced during DNA replication and held together at the centromere Sister chromatids are separated during anaphase of mitosis.
Sister chromatid
Cardiac conduction system
Efferent neuron
Chemotroph
37. A point mutation in which a pyrimidine is susbstituted for a pyrimidine - or a purine is substituted for a purine.
Circular smooth muscles
Transition mutation
Lag phase
Bronchioles
38. The allele in a heterozygous genotype that is expressed; the phenotype resulting from either a heterozygous genotype or a homozygous dominant genotype.
Enteric nervous system
Slow block to polyspermy
Thalamus
Dominant
39. DNA that is densely packed around histones. The genes in heterochromatin are generally inaccessible to enzymes and are turned off.
Heterochromatin
Ligament
Active site
Symporter
40. The region of teh brain that coordinates and smooth skeletal muscle activity.
Antiporter
Cerebellum
Enterogasterone
Pulmonary artery
41. 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
Artery
Phagocytosis
Downstream
Thrombus
42. A thick - transpartent coating rich in glycoproteins that surrounds an oocyte.
Renal tubule
Skeletal muscle
Zona pellucida
Afferent neuron
43. The loop of the nephron that dips downward into the renal medulla. The loop of Henle sets up a concentration gradient in the kidney such that from the cortex to the renal pelvis osmolarity increases. The descending limb of the loop of Henle is permea
Milk letdown
Induction
Telencephalon
Loop of Henle
44. A receptor that responds to changes in body position - such as stretch on a tendon - or contraction of a muscle. These receptor allow us to be consciously aware of the position of our body parts.
Diffusion
Motor unit
Hydroxyapatite
Proprioreceptor
45. The step in the sliding filament theory during which yosin undergoes a conformaitonal change to its low energy state - in the process dragging the thin filaments (and the attached Z lines) toward the center fo the sarcomere. NOte that power stroke re
Signal recognition particle (SRP)
Serum
Anaphase I
Power stroke
46. An organelle surrounded by a double=membrane (two lipid bilayers) where ATP production takes place. The interior (matrix) is where PDC and the Krebs cycle occur - and the inner membrane contains the enzymes of the electron trasport chain and ATP synt
Homeostasis
Penetration
Ribosome
Mitochondrion
47. 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
Collagen
Auxotroph
Epithelial tissue
48. The amount of energy required to produce the transition state of a chemical reaction. If the activation energy for a reaction is very high - the reaction occurs very slowly. Enzymes (and other catalysts) increase reaction rates by reducing activation
Reduction
Excretion
Choroid
Activation energy (Ea)
49. The ball of capillaries at the beginning of the nephron where blood filtration takes place.
Phototroph
Glomerulus
Alimentary canal
Innate immunity
50. 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
Edema
Sinoatrial (SA) node
Troponin
Voltage - gated ion channel