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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 connection of a mosin head group to an actin filament during muscle contraction (the sliding filament theory).
Cross bridge
Collecting duct
Nuclear localization sequence
Semiconservative replication
2. Plasma with the clotting factors removed. Serum is often used in diagnostic tests because it does not clot.
Serum
Dermis
Bronchioles
Chorion
3. A cytoplasmic protein that recognizes the signal sequences of proteins destined to be translated at the rough ER. It binds first to the ribosome translating the protein with the signal sequence then to an SRP receptor on the rough ER>
Renal tubule
EPSP
Lacunae
Signal recognition particle (SRP)
4. 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.
Albumin
Gene
First law of Thermodynamics
Blastocyst
5. The specific molecule that binds to a receptor.
Ligand
Siding filament theory
Anticodon
Centriole
6. The removal ( and usually the activation) of a viral genome from its host's genome.
Vitamin
Exclusion
Polysaccharides
Genotype
7. The stoppage of bleeding; blood clotting.
Hemostasis
Chemical synapse
Portal systems
Hardy- Weinberg law
8. The regino of the digestive tract where virtually al digestion and absorption occur. It is subdivided into three regions: the duodenum - the jejunum - and the ileum.
Small intestine
Axon
Oncotic pressure
Phenotype
9. An enzyme that cuts one or both strands of DNa to relieve the excess tension caused by the unwinding of the helix by helicase during replication.
Myofibril
Filtration
H zone
Topoisomerase
10. (Singular:villus). Folds of the intestinal mucosa that project into the lumen of the intestine; vili serve to increase the surface area of the intestine for absorption.
Villi
Macrophage
Synaptic cleft
Integral membrane protein
11. A genetic cross between an organism displaying a recessive phenotype (homozygous recessive) and an organism displaying a dominant phenotype (for whic the genotype is unknown) - done to determine the unknown genotype.
Analogous structures
Plaque
Testcross
Cornea
12. An alkaline - fructose - rich fluid produced by three different glands in the male reproductive tract and released during ejaculation. Semen is very nourishing for sperm.
Cross bridge
Periperal nervous system
Ileocecal valve
Semen
13. Active transport that releies on an established concentration gradient - typically set up by a primary active transporter. Secondary active transport relies on ATP indirectly.
Uterus
Optic nerve
Sclera
Seondary active transport
14. Also known as the cortical reaction - the slow block invovles an increase in intracellular [Ca2+] in the egg - which causes the release of cortical granules near the egg plasma membrane. This results in the hardening of the zona pellucida and its sep
Slow block to polyspermy
Poly- A tail
Aldosterone
Tendon
15. The intracellular process triggered by the binding of a ligand to its receptor on the cell surface. Typically this activates seond messenger pathways.
Signal transduction
Ejection fraction
Partial pressure
Prophase
16. 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
Prophase I
Chitin
Tonsils
Antigen presenting cell
17. A non - protein - but organic - molecule (such as vitamin) that is covalently bound to an enzyme as part of the active site.
Lysozyme
Pulmonary circulation
Prosthetic group
Obligate anaerobe
18. Arise in blood pH due to hyperventilation (excessive breathing) and a resulting decrease in CO2.
Respiratory alkalosis
Distal convoluted tubule
Ovulation
Endocytosis
19. The phase of the cell cycle during which the genome is replicated.
Lysozyme
Pacemaker potential
S phase
Diffusion
20. The portion of the nephron tubule after the loop of Henle - but before teh collecting duct. Selective reabsorption and secretion occur here - most notably regulated reabsorption of water and sodium.
Choroid
Pleural pressure
Distal convoluted tubule
Power stroke
21. A cell characterized by the presence of a nucleus and other membrane - bound organelles. Eukaryotes can be unicellular (protists) or multicellular (fungi - plants and animals).
Promoter
Eukaryotic
Frameshift mutation
Supercoiling
22. A pathway through a plasma membrane that restrics passage based only on the size of the molecules. Pore are made from porin proteins.
Pore
Larynx
mRNA
Thecal cells
23. Enzymes that degrade various macromolecules and that require an acidic pH to function properly. Acid hydrolases are found within the lysosomes of cells.
Purine bases
Tonsils
Acid hydrolases
Disaccharide
24. A normal blood protein produced by the liver - angiotensin is converted to angiotensim I by renin (secreted by kidney when blood pressur falls). Angiotensin I si further onverted to angiotensim II by ACE (angiotensin converting enzyme). Angiotensin I
Angiotensin
Accessory organs
Substrate(s)
Origin of replication
25. The osmotic pressure in the blood vessels due only to plasma proteins (primarily albumin) --> causes water to rush back into capillaries at end.
Interneuron
Accessory glands
Oncotic pressure
Microfilament
26. Also called thryoid hormone - thyroxine is produced and secreted by follicle cells in the thyroid gland. it targets all cells in the body and increases overall body metabolism.
Thyroxine
Transition mutation
Tonsils
Corpus luteum
27. Aromatic bases found in DNa and RNA that have a single - ring structure. They include cytosine - thymine - and uracil.
Pyrimidine bases
Diastole
Hypothalamus
Gram - positive bacteria
28. DNA that is densely packed around histones. The genes in heterochromatin are generally inaccessible to enzymes and are turned off.
Heterochromatin
Amylase
Secondary immune response
Zymogen
29. The central structure of the diencephalon of the brain. the thalamus acts as a relay station and major integrating area for sensory impulses.
Thalamus
Local autoregulation
Codon
Optic disk
30. DNA that is loosely packed around histones. This DNA is more accessible to enzymes and the genes in euchromatin can be activated if needed.
Allosteric regulation
Euchromatin
Medulla oblongata
Nucleolus
31. Extremely small pseudo - cells in the blood - important for clotting. They are not true cells - but are broken - off bits of a larger cell (a megakaryocyte).
Genetic code
Platelets
Semiconservative replication
Relication fork(s)
32. Also called vasopressin - this hormone is produced in the hypothalamus and secreted by teh posterior pituitary gland. It tartes teh kidney tubules - increasing their permeability to water - adn thus increasing water retention by the body. Also raises
Osteoclast
Substrate(s)
Antidiuretic hormone (ADH)
Resolution
33. Pepsinogen - secreting cells foudn at teh bottom of the gastric glands
Metaphase
Optic disk
Chief cells
Activation energy (Ea)
34. A subphase of male orgasm - a reflex reaction triggered by the presence of semen in the urethra. Ejaculation is a series of rhythmic contractions of muscles near teh base of teh penis that increase pressure in the urethra - forcing the semen out.
Active site
Hypodermis
Parasite
Ejaculation
35. The pressure measured in the arteries during contraction of the ventricles (during systole).
Lower esophageal sphincter
Krebs cycle
Systolic pressure
Motor unit recruitment
36. A protein hormone secreted by sustenacular cells of the testes that acts to inhibit the release of FSH and LH from the anterior pituitary.
Pyruvic acid
Heterozygous
Longitudinal muscle
Inhibin
37. 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
Afferent neuron
Epitope
Thrombus
Auxotroph
38. The first phase of the ovarian cycle - during which a follicle (an oocyte and its surroudning cells) enlarges and matures. This phase is under the control of FSH from the anterior pituitary - and typically lasts from day 1 to day 14 of the menstrual
Syncytium
Yolk sac
Neuralation
Follicular phase
39. Heterogeneous nuclear RNA; the primary transcript made in eukaryotes before splicing.
Diploid organism
hnRNA
hCG
Glucagon
40. DNA replication in which each of the parental strands is read to make a complementary daughter strand - ethus each new DNa molecule is composed of half the parental molecule paired with a newly synthesized strand.
Centromere
Simple diffsuion
Semiconservative replication
I band
41. An **inorganic molecule that associates non - covalently with an enzyme and that is required for the proper functioning of the enzyme
Internodal tract
Steroid hormone
Allele
Cofactor
42. 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.
Calmodulin
Sebaceous gland
Synapsis
Peripheral membrane protein
43. The first step in viral infection. Attachemen of a virus to its host is very specific and is also known as adsorption.
Capacitation
Attachment
Corona radiata
Accessory glands
44. Chemoreceptors on the tongue that respond to chemicals in a food.
Calcitonin
Gustatory receptors
Myosin
Oxytocin
45. The monomer of a carbohydrate. Monosaccharides have the general chemical formula CnH2nOn - and common monosaccharides include glucose - fructose - galactose - and ribose.
Autoimmune reaction
Tropic hormone
Preganglionic neuron
Monosaccharide
46. A generic connective tissue cell that produces fibers; the progenitor of all other connective tissue cell types.
Telencephalon
Semilunar valves
Desmosome
Fibroblast
47. A substance secreted by embryonic testes that causes the regression of the Mullerian ducts.
Ovary
Synovial fluid
Purkinje fibers
Mullerian inhibiting factor (MIF)
48. Also known as the neurohyophysis - the posterior pituitary is made of nervous tisssue and stores and secretes two hormones made by the hypothlamus; oxtytocin and ADH. The posterior pituitary is controlled by action potentials from the hypothalamus.
Active site
Bronchioles
Ciliary muscles
Posterior pituitary gland
49. An immune reaction directed against normal (necessary ) cells.Fo example - diabets melitus (typeI) is an autoimmun reaction directed against teh beta cells of the pancrease (destorying them and preventing insulin secretion) and aginst insulin itself.
Menstruation
Phospholipid
Autoimmune reaction
Complement system
50. An ion channel that is opened or closed based on the binding of a specific ligand to teh channel. Once opened - the channel allows the ion to cross the plasma membrane according to its concentration gradient. An examples is the acetylcholine receptor
Bipolar neuron
Ligand - gated ion channel
Antigen presenting cell
Effector organ