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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. (singular alveolus.) Tiny sacs - with walls only a single cell layer thick found at the end of the respiratory bronchiole tree. Alveoli are the site of gas exchange in the respiratory system.
Aldosterone
Alveoli
Ligament
Ureters
2. The principal mineralocorticoid secreted by teh adrenal cortex. This steroid hormone targets the kidney tubules and increases renal reabsorption of sodium [and excretion of potassium]. (this causes ADH to be secreted & increased water comes out - inc
Nondisjunction
Aldosterone
Skeletal muscle
Nucleotide
3. Photoreceptors in the retina of the eye that respond to dim light and provide us with black and white vision.
Prosthetic group
Symporter
Ectoderm
Rods
4. 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).
Choroid
Platelets
Adrenergic tone
Coccus
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.
Basement membrane
Conjugation
Adipocyte
Memory cell
6. Also known as the Bundle of His - this is the first portion of the cardiac conduction system - after the AV node.
Atrioventricular valves
Choroid
Lipoprotein
Atrioventricular bundle (AV) bundle
7. The basic functional and structural unit of the nervous system. The neuron is a highly specialized cell - designed to transmit action potentials.
Seminal vesicles
Dorsal root ganglion
Neuron
Cerebellum
8. The process of breaking down large molecules into smaller precursors - e.g. digesion of starch into glucose.
Catabolism
Poly- A tail
Cerebellum
Gram - positive bacteria
9. The tube that connects the middle ear acity with the pharynx; also known as the Eustachian tube. Its fucntion is to equalize midle ear pressure with atmospheric pressure so that pressure on boths sides of the tympanic membrane is the same.
Auditory tube
Saprophyte
Noncompetitive inhibitor
Repolarization
10. 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.
Basilar membrane
Gastrulation
Follicle
Temporal summation
11. A chemical derived from vitamin A found in the pigment proteins of the rod photoreceptors of the retina. Retinal changes conformation when it absorbs light - triggering a series of reactions that ultimately result in an action potential being sent to
Retinal
Portal systems
Signal sequence
Gallbladder
12. The first (approximately 5%) of the small intestinte.
Duodenum
Mutualism
Anabolism
ATP synthase
13. 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.
Telophase II
Neuron
Fetal stage
Baroreceptor
14. A point mutation in which a pyrimidine is substitued for a purine - or vice versa.
Transversion mutation
RNA polymerase
Pulmonary circulation
Replication bubbles
15. Major Histocompatability complex - a set of proteins found on the plasma membranes of cells that help display antigen to T cells. MHC I is found on all cells and displays bits of proteins from within the cell; this allows T cells to monitor cell cont
MHC
Dynein
Ileocecal valve
Haploid organism
16. The movement of a hydrophobic molecule across the plasma membrane of cell - down its concentration gradient. Since the molecule can esialy interact with the lipid bilayer - no additional help (such as a channel or pore) is required.
Simple diffsuion
Phagocytosis
Homologous chromosomes
Fermentation
17. The ability of tissues to regulate their own blood flow in the absence of neural stiulation. THis is generally accomplished via metabolic wastes (such as CO2) that act as vasodilators.
Glycolipid
Local autoregulation
Proximal convoluted tubuel
Organogenesis
18. An organism that requires the aid of a host organism to survive - and that harms the host in the process.
Parasite
hnRNA
Innate immunity
T cell
19. A concentrated region of white blood cells found along the vessels of the lympatic system.
Nodes of Ranvier
Androgens
Primary oocytes
Lymph node
20. Hardy crystals consisting of calcium and phosphate that form the bone matrix.
Reduction
Dendrite
Hydroxyapatite
End plate potential
21. A hormone secreted by the small intestine (duodenum) in response to the presence of food. It decreases the rate at which chyme leaves the stomach and enters the small intestine.
Enterogasterone
Somatic nervous system
Renal absorption
G- protein linked receptor
22. The plasma membrane of a muscle cell.
Diploid organism
Na+/K+ ATPase
rRNA
Sarcolemma
23. 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
White matter
Integral membrane protein
Promoter
urfactant
24. The curled structure in the inner ear that contains the membranes and hair cells that transduce sound waves into action potentials.
Conjugation
Aqueous humor
Adenine
Cochlea
25. A haploid but immature cell resulting from the second meiotic division f spermatogenesis. Spermatids undergo significant physical changes to become mature sperm (spermatozoa).
Spermatid
Large intestine
Hemoglobin
Synaptic cleft
26. Movement of a hydrophilic molecuel across the plasma membrane of a cell - down its concentration gradient - through a channel - pore - or carrier molecule in the membrane. Because the hydrophilic nature of the molecule - it requires a special path th
Jejunum
Facilitated diffusion
Genome
Transduction
27. The environment in which or upon Which bacteria grow. It typically contains a sugar source and any other nutrients that bacteria may require. 'Minimal medium' contain nothing but glucose.
Tropic hormone
Medium
Electrical synapse
Nucleolus
28. 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).
Anal sphincter
Hemoglobin
Gram - positive bacteria
Thalamus
29. MRNA that codes forsingle type of protein - such as is found in eukaryotic cells.
rRNA
Monocistronic mRNA
Epiphysis
Cardiac conduction system
30. The portion of the brain responsible for visual and auditory startle reflexes.
Testes
Maternal inheritance
Seminiferous tubules
Midbrain
31. A long - coiled duct on the outside of the testis in which sperm mature.
Operator
Epididymis
Corticosteroids
Inflammation
32. The three glands in the male reproductive system that reproduce semen: the seminal vesicles - the prostate - and the
Tympanic membrane
Corpus callosum
Intercostal muscles
Accessory glands
33. The normal configuration of double - stranded DNA in which the 5' end of oen strand is paired with the 3' end of the other
Lipid
Synaptic cleft
Systole
Antiparallel orientation
34. A person with blood type AB+. Because this person's red blood cells possess all of the typical blood surface proteins - they will not display an immune reaction if transfused with any of the other blood types.
Total lung capacity
Seminiferous tubules
Spirochete
Universal acceptor
35. A prokaryotic enzyme used to twist teh single circular chromosome of prokaryotes upon itself to form supercois. Supercoiling helps to compact prokaryotic DNa and make it sturdier.
Gyrase
Hemoglobin
Medulla
P site
36. The small artery that carries blood toward the capillaries of the glomerulus.
Na+/K+ ATPase
Intercostal muscles
Nucleotide
Afferent arteriole
37. The outermost layer of teh skin. The epidermis is made of epithelial tissue that is constantly dividing at the bottom; teh cells migrate to teh surface (dying along the way) to be sloughed off at the suface.
Epidermis
Lytic cycle
Interstitial cell
Splicing
38. The movement of molecules through the plasma membrane against their concentration gradients. Active transport requires input of cellular energy - often in the form of ATP. An example is the Na+/K+ ATPase in the plasma membrane of all cells.
Hemoglobin
Attachment
Cilia
Active transport
39. 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
Synapsis
Tidal volume
Sudoriferous gland
40. A flexible piece of cartilage in the larynx that flips downward to seal teh trachea during swallowing.
Smooth Endoplasmic Reticulum
Pepsin
Soma
Epiglottis
41. DNA replication in prokaryotes - so named because as replication proceeds around the single - circular chromosome - it takes on the appearnce of the Greek letter theta.
Antibody (Ab)
Antigen (Ag)
Theta replication
Depolarization
42. A substance secreted by embryonic testes that causes the regression of the Mullerian ducts.
Nucleolus
Erythropoietin
Mullerian inhibiting factor (MIF)
Dense connective tissue
43. A form of evolution in which the same organism is placed into different environments with different selection pressures. This causes organisms to evolve differently - to diverge from their common ancestor. The resulting (new) species may share struct
Divergent evolution
Transduction
Productive cycle
T cell
44. The flow of blood through a tissue; ischeia is when there is no blood flow - anoxia when there is no O2 available (ischemia is more dangerous b/c of waste build - up)
hnRNA
Perfusion
Hair cells
Primary active transport
45. Something that acts to oppose the action of something else. For example - muscles that move a join in oppoiste direction are said to be antagonists.
Ectoderm
Antagonist
Carbonic anhydrase
Diastolic pressure
46. 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
Follicular phase
Law of Independent Assortment
Polysaccharides
Trachea
47. The portion of the placenta derived from the zygote.
Chymotrypsin
Shine - Dalgarno sequence
Adrenal medulla
Chorion
48. The mechanism of contraction in skeletal and cardiac muscl cells. It is a series of four repeated steps: (1) myosin binds actin - (2) myosin pull actin toward the center of the sarcomere (3) myosin releases actin - and (4) myosin resets to its high -
Compact bone
Thalamus
Testosterone
Siding filament theory
49. An ion channel specific for potassium found in the plasma membrane of all cells in the body. Leak channels are constitutively open and allow their specifi ion to move across the membrane according to its gadient. Potassium leak channels allow potassi
Uniporter
Potassium leak channel
Matrix
Nodes of Ranvier
50. Very small air tubes int eh respiratory system (diameter 0.5 - 1.0 mm). The walls of the bronchioles are made of smooth muscle (thus involunatry) to help regulate air flow.
Corticosteroids
Bronchioles
Purkinje fibers
Sertolli cells