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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. A point mutation in which a codon that specifies an amino acid is mutated into a new codon that specifies the same amion acid.
Anterioir pituitary gland
Accessory organs
Silent mutation
Capacitation
2. The division of the autonomic nervous system known as the 'fright or flight' system. It causes a genera increase in body activities such as heart rate - respiratory rate - and blood pressure - and an increase in blood flow to skeleltal muscle. It cau
Secondary sex characteristics
Codominance
Peptide hormone
Sympathic nervous system
3. The first phase of meiosis II. Prophase II is identical to mitotic prophase - except that the number of chromosomes was reduced by half during meiosis I.
Gibbs free energy
Prophase II
Osmotic pressure
Acetylcholine (Ach)
4. A ductless gland that secretes a hormone into the blood
Incomplete dominance
Enteric nervous system
Endocrine gland
Keratin
5. The reduced form of NAD+ (nicotinamide adenine dinucleotide). This is the most common electron carrier in cellular respiration.
NADH
Lysosome
Ligand
Olfactory receptors
6. The allele in a heterozygou genotype that is not expressed; the phenotype resulting from possession of two recessive alleles (homozygous recessive).
Thyroxine
Sex- linked rait
Implantation
Recessive
7. The primary male sex organ. The testes are suspended outside the body cavity in the scrotum and have two functions (1) produce sperm - and (2) secrete testosterone.
Dorsal root ganglion
Testes
Bacilus
Adipocyte
8. The cells of the distal tubule at the juxtaglomerular apparatus. They are receptors that monitor filtrate osmolarity as a means of regulatin filtration rate. If a drop is osmolarity is sensed - the macula densa dilates the afferent arteriole (to incr
Macula densa
Mitosis
Replication
Collecting duct
9. The 'blind spot' of the eye - this is where the axons of the ganglion cells exist the retinal to form the optic nerve. There are no photoreceptors in the optic disk.
Lytic cycle
Gap junction
Optic disk
Lacteals
10. A trop hormone produced by the anterior pituitary gand that targets the adrenal cortex - stimulating it to relase corisol and aldosterone.
Na+/K+ ATPase
Polysaccharides
Thrombus
Adrenocoricotropic hormone (ACTH)
11. A helical protein that winds around actin helices in skeletal and cardiac muscle cells to form the thin filament of the sarcomere. In the absence of Ca2+ - tropomyosin covers the myosin - binding sites on actin and prevents muscle contraction. When c
Neurotransmitter
Exotoxin
Tropomyosin
RNA polymerase
12. A receptor that responds to changes in temperature.
Mullerian inhibiting factor (MIF)
Thermoreceptor
Recombination frequency
Secondary spermatocytes
13. The maximum amount of air that can be forcibly exhaled from the lungs after filling them to their maximum level - typically about 4500 mL
End plate potential
Vital capacity
Catabolism
Aorta
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
Graafian follicle
Acrosome
Pyruvic acid
Hypodermis
15. The portion of the brain responsible for visual and auditory startle reflexes.
Calmodulin
Erythropoietin
Optic disk
Midbrain
16. 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
Point mutation
Power stroke
Erythropoietin
Organogenesis
17. 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.
Resting membrane potential
First law of Thermodynamics
Heterochromatin
Menstruation
18. The specific molecule that binds to a receptor.
Ligand
Primary active transport
Reduction
Anaphase II
19. A protein channel in the nuclear envelope that llows the free passage of molecules smaller than 60 kD.
Metaphase II
Nuclear pore
Downstream
A band
20. One type of eukaryotic mRNA processing in which introns are removed from the primary transcript and exons are ligated together. SPlicing of transcripts can be different in different tissues.
Splicing
Mucosa
Frank Starling mechanism
Humoral immunity
21. A clump of gray matter (unmyelinated neuron cell bodies) found in the peripheral nervous system.
Enterogasterone
Cerebral cortex
Ganglion
Homozygous
22. Oil - forming glands found all over the body - especially on the face and neck. The product (sebum) is released to the skin surface through hair follicles.
Posterior pituitary gland
Osteoblast
Simple diffsuion
Sebaceous gland
23. An organelle bounded by a double membrane (double lipid bilayer) called the nuclear envelope. The nucleus contains the genome and is the site of replication and transcription.
Villi
Differentiation
Nucleus
Chemical synapse
24. A hormone produced and secreted by teh adrenal medulla that prolongs and increases teh effects of the sympathetic nervous system.
Epinephrine
Sinoatrial (SA) node
Medium
Epistasis
25. A long projection on a bacterial surface involved in an attachment - e.g. - the sex pilus attaches F+ and F- bacteria during conjugation.
Phenotype
Memory cell
Pilus
Labor contractions
26. Aromatic bases found in DNa and RNA that have a single - ring structure. They include cytosine - thymine - and uracil.
Lysosome
Pyrimidine bases
Spatial summation
Adrenergic tone
27. A statistical rule stating that the probability of either of two indpendent (and mutually exclusive) events ocuring is the sum of their individual probabilities minus the probability of them both occuring together.
Neurotransmitter
Norepinephrine
Heterozygous
Rule of addition
28. A neuron with a single axon and multiple dendrites; the most common type of neuron in the nervous system.
Incomplete dominance
Multipolar neuron
Tonsils
Lysogenic cycle
29. The modifaction of enzyme activity through interactino of molecules with specific sites on the enzyme other than the active site (called allosteric sites)
Formed elements
Efferent arteriole
Fibroblast
Allosteric regulation
30. An integral protein that selectively allows molecules across the plasma membrane. See also entries under 'ion channel' - 'voltage - gated channel' - and 'ligand - gated channel'.
Sertolli cells
Corpus luteum
Channel protein
Operator
31. The removal ( and usually the activation) of a viral genome from its host's genome.
Atrioventricular (AV) node
Thyroid stimulating hormone (TSH)
Adenohypophis
Exclusion
32. 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
Tight junction
Poly- A tail
Determination
G- protein linked receptor
33. The final phase of the digestive tract - also called the colon. The primary funcion of the large intestine is to reabsorb water and to store the feces.
Large intestine
Lipoprotein
Telophase I
Spirochete
34. A blood protein produced by the liver. Albumin helps to mantain blood osmotic pressure (oncotic pressure)
Creatine Phosphate
Capilary
Albumin
Euchromatin
35. 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
Cerebellum
Catabolism
Origin of replication
Loop of Henle
36. The most common class of bone in the body - long bones have a well - defined shaft (the diaphysis) and two well - defined ends (the epiphyses).
H zone
Long bone
Nuclear pore
Erythropoietin
37. One of the four basic tissue types in the body (epithelial - connective - muscle - and nervous). Epithelial tissue is a lining and covering tissue (e.g. skin - the lining of the stomach and intestines - the lining of the urinary tract - etc. ) or a g
Serum
Epithelial tissue
Hyperpolarization
Acinar cells
38. Muscle tissue that is attached to the bones. SKeletal muscle is striated multinucleate - and under voluntary control.
Skeletal muscle
Ptyalin
Lacunae
Heterochromatin
39. The first branches of the trachea. There are two primary bronchi - one for each lung.
Diastole
FSH
Primary bronchi
Epitope
40. 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
Activation energy (Ea)
Epidermis
Universal donor
Signal transduction
41. The osmotic pressure in the blood vessels due only to plasma proteins (primarily albumin) --> causes water to rush back into capillaries at end.
Oncotic pressure
Sebaceous gland
Peptide bond
Facilitated diffusion
42. A specialized region at the ends of eukaryotic chromosmes that contains several repeats of a particular DNA sequence. These ends are maintained (in some cells) with the help of a special DNA poymerase called telomerase. In cells that lack telomerase
Telomere
Coronary vessels
Mullerian ducts
Serum
43. The third phase of the uterin (endometrial) cycle - during which the rebuilt endometrium is enhanced with glycogen and lipid stores. The secretory phase is primarily under the controll of progestone and estrogen (secreted from the copus luteum during
Secretory phase
Aldosterone
Resolution
Sarcoplasmic reticulum
44. An organs in the abdominal cavity with two roles. The first is an exocrine role: to produce digestive enzymes and bicarbonate - which are delivered to the small intestine via the pancreatic duct. The second is an endocrine role: to secrete insulin an
Replication
Gonadotropin releasing hormone (GnRH
Mesoderm
Pancreas
45. One of the four aromatic bases found in DNA and RNA. Guanine is a purine; it pairs with cytosine.
Respiratory acidosis
Diencephalon
Guanine
Phosphofructokinase
46. The fourth of meiosis I. Telophase I is identical to mitotic telophase - except that the number of chromosoms is now reduced by half. After this phase the cell is considered to be haploid. Note however - that the chromosomes are still replicated - an
Repolarization
Golgi apparatus
Telophase I
Anal sphincter
47. The smallest (and final) fibers in the cardiac conduction system. The Purkinje fibers transmit the cardiac impulse to the ventricular muscle.
Inner cell mass
Purkinje fibers
Diaphysis
Na+/K+ ATPase
48. A hormone produced from vitamin D that acts in essentially the same manner as parathyroid hormone.
Calcitriol
Erectile tissue
Glomerulus
Partial pressure
49. A sweat gland located in the dermis of the skin. Sweat consists of water and ions (including Na+ and urea) and is secreted with temperatures rise.
Wolffian ducts
Periplasmic space
Sudoriferous gland
Placenta
50. A large system of folded membranes within a eukaryotic cell that has ribosomes bound to it - giving a rough appearnce. These ribosomes synthesize proteins that will ultimately be secreted from the cell - incorporated into the plasma membrane - or tra
Diastolic pressure
Rough endoplasmic reticulum
Myofiber
Alveoli