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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 layer of ciliated - mucus - covered cells in the respiratory tract.The cilia continually beat - sweeping contaminated mucus upward toward the pharynx.
Synapsis
Mucocilliary escalator
tRNA loading
Small intestine
2. The plasma membrane of a muscle cell.
Sarcolemma
Interphase
Androgens
Luteinizing Hormone (LH)
3. An immune organ located near the heart. THe thymus is the site of T cell maturation and is larger in children and adolescents.
Thymus
Spatial summation
hCG
Optic nerve
4. A nucleotide sequence on DNA that contians three elemtns: a coding sequence for one or more enzymes - *a coding sequence for a regulatory protein - and upstream regulatory sequences where the regulatory proteins can bind. An example is the lac operon
Operon
Crossing over
Calcitonin
Goblet cells
5. 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
Exocrine gland
Plasma
Meiosis
Motor end plate
6. The volume of blood pumped out the heart in a single contraction.
Platelets
Lagging strand
Steroid hormone
Stroke volume
7. The first step in viral infection. Attachemen of a virus to its host is very specific and is also known as adsorption.
Attachment
Lymph node
Phosphofructokinase
Calcitriol
8. A red blood cell; they are filled with hemoglobin - and teh function of the erythrocytes is to carry oxygen in the blood.
Menstruation
Diaphysis
Erythrocyte
Placental villi
9. A globular protein that ssociated with tropomyosin as part of the thin filament of the sarcomere. Troponin binds Ca2+ - which causes the conformaiton change in tropomyosin required to expose the myosin - binding sites on actin and initiate muscle con
Desmosome
Mullerian ducts
Anal sphincter
Troponin
10. 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
Exotoxin
Residual volume
Skeletal muscle
Pyruvic acid
11. A hormone produced and secreted by teh adrenal medulla that prolongs and increases teh effects of the sympathetic nervous system.
Epinephrine
Diastolic pressure
Ovary
Ligase
12. The primary membrane lipid. Phospholipids consist of a glycerol molecule esterified to two fatty acid chains and a phosphate molecule. Additional - highly hyrohpilic groups are attached to the phosphate - making this molecule extremely amphipathic.
Aorta
Centromere
Total lung capacity
Phospholipid
13. A point mutation in which a codon that specifies an amino acid is mutated into a new codon that specifies the same amion acid.
Silent mutation
Epithelial tissue
Synaptic cleft
Bacteriophage
14. The portion of the hindbrain that controls respiratory and blood pressure - and specialized digestive and respiratory functions such as vomiting - sneezing - and coughing.
Medulla oblongata
Primary spermatocytes
Villi
Kinase
15. A molecule composed of two monosaccharides. Common disaccharides include maltose - sucrose - and lactose.
Disaccharide
Bile
Prolactin
Repressible enzyme
16. The failure of homologous chromosomes or sister chromatids to separate properly during cell division. This could ocur during anaphase I of meiosis (homologous chromosomes) [--> leaving 2 gametes w/ 2 copies and 2 gametes w/ no copies of chromosome] -
Obligate aerobe
Alveoli
Nondisjunction
Facultative anaerobe
17. Mal sex hormones. Testosteron is the primary androgen.
Fimbriae
Androgens
Submucosa
Spermatogenesis
18. In the autonomic division of the PNS - a neuron that has its cell body located in the autonomic ganglion (where a preganglionic neuron synapses with it) and whose axon synapses with the target axon.
Diastole
Purkinje fibers
Purine bases
Postganglionic neuron
19. An organ that develops during pregnacy - derived in part from the mother and in part from the zygote. The placenta is the site of exchange of nutrients and gases between the mother's blood and the fetus' blood. The placenta is formed during the first
Bile
Ileum
Placenta
Oxytocin
20. A type of lipoprotein; the form in which absorbed fats from the intestines are transported to the circulatory system.
Chylomicron
Facultative anaerobe
Hypodermis
Uracil
21. The membrane surrounding the DNA in eukaryotic cells made of two lipid bilayers.
Chemotroph
Ileocecal valve
Nuclear envelope
Myofiber
22. An integral protein that selectively allows molecules across the plasma membrane. See also entries under 'ion channel' - 'voltage - gated channel' - and 'ligand - gated channel'.
Cardiac output
Glycolipid
Obligate aerobe
Channel protein
23. The largest artery in teh body; the aorta carries oxygenated blood away from the left ventricle of the heart.
T tubules
Bacteriophage
Sarcolemma
Aorta
24. The first phase of the uterine (endometrial) cycle - during which the endometrium from the previous cycle is shed off. Estrogen and progesterone levels are low during this time period. Menstruation typically lasts from day 1 to day 5 of the cycle.
Menstruation
Poly- A tail
Pyloric sphincter
Diastole
25. A flexible piece of cartilage in the larynx that flips downward to seal teh trachea during swallowing.
Soma
Noncompetitive inhibitor
Epiglottis
Proliferative phase
26. The 3D site of an enzyme where substrates (reactants) bind and a chemical reaction is facilitated.
Leading strand
Urethra
Meninges
Active site
27. 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
Fibrinogen
Neuron
Aminoacyl tRNA
28. A group of blood proteins that bind non - specifically to the surface proteins of foreign cells (such as bacteria) - ultimately leading to the destruction of the foreign cell - part of the innate immunity.
Topoisomerase
Rule of multiplication
Semilunar valves
Complement system
29. A long projection on a bacterial surface involved in an attachment - e.g. - the sex pilus attaches F+ and F- bacteria during conjugation.
Homologous chromosomes
Channel protein
Albumin
Pilus
30. A sensory receptor that responds to hcanges in pressure; for example - there are baroreceptors in the carotid arteries and the aortic ach that monitor blood pressure.
Baroreceptor
Cholecystokinin (CCK)
Thalamus
Nuclear localization sequence
31. The pressure measured in the arteries during contraction of the ventricles (during systole).
Systolic pressure
MHC
Antiporter
Macula densa
32. The modifaction of enzyme activity through interactino of molecules with specific sites on the enzyme other than the active site (called allosteric sites)
Secondary oocyte
Telophase II
Allosteric regulation
Systemic circulation
33. A globular protein found in muscle tissue that has the ability to bind oxygen. Myoglobin helps to store oxygen in the muscle for use in aerobic respiration (it does not move - just stays there). Muscles that participate in endurance activities (inclu
Cortex
Myoglobin
Diaphysis
Residual volume
34. An RNA polymerase that creates a primer (made of RNA) initiate DNa replication. DNA pol binds to the primer and elongates it.
Osteon
Actin
Lactic acid
Primase
35. A bundle of skeletal muscle cells. Fascicles group together to form skeletal muscles.
Transmembrane domain
Milk letdown
Fascicle
Functional synctium
36. Also called simply - 'islet cells' these are the endocrine cells of the pancreas. Different cell types wihtin the inslets secrete insulin - glucagon - and somatostatin
Avascular
Nuclear localization sequence
Islets of Langerhans
Gonadotropin releasing hormone (GnRH
37. The specialized cells of the heart that spontaneously initiate action potentials and transmit them to the cardiac muscle cells. The cells of the conduction system are essentially cardiac muscle cells - but lack the contractile fibers of the muscle ce
Cardiac conduction system
Temporal summation
Proliferative phase
Fascicle
38. A type of lymphocyte that can recognize (bind to) an antigen adn secrete an antibody specific for that antigen. When activated by binding an antigen - B cells mature into plasma cells (that secreted antibody) and memory cells (that patrol the body fo
Primary active transport
B cell
Nucleosome
Cortisol
39. A structure composed of a ribose molecule linked to one of the aromatic bases. In a deoxynucleoside - the ribose is replaced with deoxyribose.
Pupil
Peroxisome
Interleukin
Nucleoside
40. A contractile protein. In skeletal and cardiac muscle - actin polymerizes (along with other proteins) to form the thin filaments. Actin is involved in many contractile activities - such as cyotkinesis - pseudopod formation - and muscle contraction.
Actin
Sarcolemma
Universal acceptor
MHC
41. A hormone secreted by the samll intestine (duodenum) in response to the presence of fats. It promotes release of bile from the gallbladder and pancreatic juice from the pancreas - and reduces stomach motility.
Cholecystokinin (CCK)
Spirochete
Telophase II
Preganglionic neuron
42. The percentage of individuals with a particular genotype that actually displays the phenotype associated with the genotype.
Testcross
Penetrance
Homozygous
Leak channel
43. A mutation caused by an insertion or deletion of base pairs in a gene sequence in DNA such that the reading frame of the gene (and thus teh amino acid sequence of the protein) is altered.
Telophase
Respiratory alkalosis
Primary active transport
Frameshift mutation
44. A substance secreted by embryonic testes that causes the regression of the Mullerian ducts.
Mullerian inhibiting factor (MIF)
Repressor
Dominant
Nonsense mutation
45. A type of white blood cell; leukocytes are either B or T cells and are involved in disease defense.
Corpus callosum
Haploid organism
Hypothalamus
Leukocyte
46. 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
Antidiuretic hormone (ADH)
Thermoreceptor
Baroreceptor
H zone
47. One of the four aromatic bases found in DNA and RNA. Cytosine is a pyrimidine; it pairs with guanine.
Testes
Anaphase I
Acinar cells
Cytosine
48. The first part of the large intestine.
Iris
Exocytosis
Cecum
Humoral immunity
49. Toward the 3' end of an RNA transcript (the 3' end of the DNA coding strand). Stop codons and (in eukaryotes) the pol - A tail are found 'downstream.'
Adenohypophis
Transmembrane domain
Downstream
Menstruation
50. A receptor that responds to light
Photoreceptor
Cerebral cortex
Gibbs free energy
Glomerulus