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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. Excitatory postsynaptic potential; a slight depolarization of a postsynaptic cell - bringing the membrane potential of that cell closer to the threshold for an action potential.
EPSP
Genetic code
Uracil
Origin of replication
2. The portion of an integral membrane protein that passes through the lipid bilayer.
Transmembrane domain
Nucleosome
Lipoprotein
Totipotent
3. The phase of mitosis during which the cell physically splits into two daugter cells. Cytokinesis begins near the end of anaphase - and is completed during telophase.
Peripheral membrane protein
Phenotype
Cytokinesis
Guanine
4. 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
Progesterone
Inhibin
Functional synctium
Formed elements
5. A string of several hundred adenine nucletodies added to the 3' end of the eukaryotic mRNA.
Periplasmic space
Exclusion
Retina
Poly- A tail
6. The portion of the ear consisting of the pinna and the external auditory canal. The outer ear is separated from the middle ear by the tympanic membrane (the eardrum).
Lag phase
Outer ear
Ejaculation
Transduction
7. A cell surface receptor associated with an intracellular protein that binds and hydrolyzes GTP. When GTP is bound - the protein is active - and can regulate the activity of adenylyl cyclease; this modifies the intracellular levels of second messenger
Semen
G- protein linked receptor
Islets of Langerhans
Bone marrow
8. A passageway leading from behind the nasal cavity to the trachea. The pharynx is divided into three regions - named for their location. The nasopharynx is behind the nasal cavity - the oropharynx is behind the oral cavity - and the laryngopharynx is
Midbrain
Hardy- Weinberg law
Trophoblast
Pharynx
9. A blood protein produced by the liver. Albumin helps to mantain blood osmotic pressure (oncotic pressure)
Smooth muscle
Submucosa
Allosteric regulation
Albumin
10. The return of membrane potential to normal resting values after a depolarization of hyperpolarization.
Cofactor
Oxaloacetate
Labia
Repolarization
11. The allele in a heterozygous genotype that is expressed; the phenotype resulting from either a heterozygous genotype or a homozygous dominant genotype.
Dominant
Exocytosis
Homozygous
Osteoclast
12. The layer of connective tissue directly under the mucosa of an open body cavity.
Optic disk
Effector organ
A band
Submucosa
13. 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
Actin
Gibbs free energy
Somatic nervous system
Fascicle
14. Steroid hormones secreted from the adrenal cortex. The two major classes are teh mineralocorticoids and glucocorticoids. Aldosterone is the principal mineralocorticoid - and cortisol is the principal glucorcorticoid.
Midbrain
Cilia
Corticosteroids
Peroxisome
15. A rigid structure at the top of the trachea (so it is part of trachea - I assume) made completely out of cartilage. The larynx has three main functions: (1) its rigidness ensures that the trachea is held open (provides an open airway). (2) the epiglo
Larynx
Accessory organs
Follicle
Aminion
16. The contribution of an individual gas to the total ppressure of a mixture of gases. Partial pressures are used to describe the amounts of the various gases carried in the bloodstream.
Partial pressure
Osmosis
Actin
Mullerian ducts
17. A protein channel in a cell membrane that is specific for a particular ion - such as Na+ or K+. Ion channels may be constitutively open (leak channels) - or regulated (voltage - gated or ligand - gated).
Aorta
Nociceptors
Ion channel
Somatic nervous system
18. The 28 days of the menstrual cycle as they apply to the events in the uterus. The endometrial cycle is also known as the uterine cycle - and has the three subphases: menstruation - the proliferative phase - and the secretory phase.
Endometrial cycle
Sarcolemma
Telophase I
Myosin light - chain kinase (MLCK)
19. The primary androgen (male sex steroid). Testosterone is a steroid hormone produced and secreted by the interstitial cells of the testes. It triggers the development of secondary male sex characteristics during puberty (including spermatogenesis) and
Pancreatic duct
Avascular
Frameshift mutation
Testosterone
20. A toxin that secreted by a bacterium into its surrounding medium that help the bacterium compete with other species. Some exotoxins cause serious disease in humans (botulism - tetanus - diptheria - toxic shock syndrome).
Exotoxin
Ligament
Renin
Auxotroph
21. A microscopic space between the axon of one neuron and the cell body or dendrites of a secon neruon - or between the axon of a neuron and an organ.
Dense connective tissue
Duodenum
Chemoreceptor
Synaptic cleft
22. The period of human development from implantation through 8 weeks of gestation. Gastrulation - neurulation - and organogenesis occur during this time period. The developing baby is known as embryo during this time period.
Optic nerve
Spatial summation
Epistasis
Embryonic stage
23. All the genetic information in an organism; all of an organism's chromosomes.
Outer ear
Adenohypophis
Genome
Mucosa
24. Bacteria that have a thick peptido glycan cell wall - and no outer membrane. They stain very darkly (purple) in Gram stain.
Tonsils
Ventricle
Renal tubule
Gram - positive bacteria
25. Plasma with the clotting factors removed. Serum is often used in diagnostic tests because it does not clot.
Mesoderm
Penetrance
Serum
Accessory glands
26. A region within the nucleus where rRNA is transribed and ribosomes are partially assembled.
Motor unit recruitment
Coenzyme
Nucleolus
Antigen (Ag)
27. 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
Lipoprotein
Pepsin
Intercalcated discs
Oxidative phosphorylation
28. Mendels' first law. The Law of Segregation states that the two alleles of a given gene will be separate from one another during gamete formation (meiosis).
Fermentation
Diaphysis
Active site
Law of Segregation
29. A chemical secreted by a T cell (usually the helper Ts) that stimulates activation and proliferation of other immune system cells.
Hematopoiesis
Lymphokine
Cardiac output
Ligand
30. 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.
Trachea
Autonomic nervous system (ANS)
Universal donor
Cholesterol
31. A point mutation in which a condon that specifies an amino acid is mutated into a stop (nonsense) codon.
Nonsense mutation
Antiporter
Vasa recta
Serum
32. The first phase of meiosis I. During prophase I the replicated chromosomes condense - homologous chromsomes pair up - crossing over occurs between homologous chromosomes - the spindle is formed - and the nuclear envelope breaks apart into vesicles. P
Missense mutation
Prophase I
Ribosome
Convergent evolution
33. 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
Soma
Peptide hormone
Catabolism
Gram - positive bacteria
34. A chemical released by the axon of a neuron in response to an action potential that binds to receptors on a postsynaptic cell and causes that cell to either depolarize slightlly (EPSP) or hyperpolarize slightly (IPSP). Examples are acetylcholine - no
Collecting duct
Anticodon
Neurotransmitter
Vagal tone
35. 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
Voltage - gated ion channel
Lysozyme
Universal donor
Enteric nervous system
36. A peptide hormone produced and secreted by the alpha cells - of the pancreas. It tartes primarily the liver - stimulating the breakdown of glycogen - thus increasing blood gluocse level.s
Myelin
Systemic circulation
Homozygous
Glucagon
37. One of the two small chambers in the heart that receive blood and pass it on to the ventricles. The right atrium receives deoxygenated blood from teh body through the superior and inferiro vena cavae - adn the left atrium receives oxygenated blood fr
Atrium
Oval window
Rule of multiplication
Bohr effect
38. The pressure measured in the arteries while the ventricles are relaxed (during diastole).
Diastolic pressure
Depolarization
Inflammation
Villi
39. 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.
Neuromuscular junction
Luteinizing Hormone (LH)
Pancreas
rRNA
40. A large - mature - ovarian follicel with a well - developed antrum and a secondary oocyte. Ovulation of the oocyte occurs from this type of follicle.
Graafian follicle
Carbohydrates
Purine bases
Proliferative phase
41. A clear fluid the circulates around through the brain and spinal cord that helps to physially support teh brain and act as a shock absorber - and taht also exchanges nutrients and wastes with teh brain and spinal cord.
Cerebrospinal fluid
mRNA
Signal sequence
Fluid mosaic model
42. The non - specific uptake of liquid particles into a cell by invagination of the plasma membrane and subsequent 'pinching off' a small bit of the extracellular fluid.
Placenta
Enterokinase
Pinocytosis
Tight junction
43. 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.
Chemical synapse
Osmotic pressure
Enteric nervous system
Inner cell mass
44. 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
Anaphase I
Central chemoreceptors
Depolarization
Cyclic AMP (cAMP)
45. An enzyme that transcribes RNa. Prokaryotes have a single RNA pol - while eukaryotes have three; in eukaryotes - RNA pol I transcribes rRNA - RNA pol II transcribes mRNA - and RNA pol III transcribes tRNA.
White matter
RNA polymerase
Hepatic portal vein
Mullerian inhibiting factor (MIF)
46. The enzyme that breaks down acetylcholine in the synaptic cleft.
Interneuron
Acetylcholinesterase (AChE)
F (fertility) factor
Atrioventricular valves
47. Movement that is directed by chemical gradients - such as nutrients or toxins. (seen in some bacteria)
Thymine
Microfilament
Chemotaxis
Power stroke
48. Molecules made from monosaccharides that serve as the primary source of cellular energy -. Carbohydrates can also act as cell surface markers (good thing to remember).
Functional synctium
Universal acceptor
Repressible enzyme
Carbohydrates
49. A fibrous - connective - tissue protein taht has the ability to recoil to its original shape after being stretche.d Elastin is found in great amounts in lung tissue - arterial tissue - skin - and the epiglottis.
Bulbourethral galnds
Dermis
Binary fission
Elastin
50. The depolarization of the egg plasma membrane upon fertilization - designed to prevent the entry of more than one sperm into the egg.
Fast block to polyspermy
Telomere
Saltatory conduction
Tendon