Test your basic knowledge |

MCAT Prep - 2

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. chylomicron concentration in blood after meal
Salivary amylase; both hydrolyze glycosidic linkages
Apoproteins attach to outside of globules; these move to Golgi and are released into interstitial fluid via exocytosis as chylomicrons --->most go to lacteal system
Somatic sensory = dorsal root ganglia (outside spinal cord); somatic effector = ventral horns of spinal cord
Peak at 1-2hr after meal; chylomicrons themselves have half - life of about 1hr after formation in enterocytes

2. Which fats are not absorbed like this
Digestion
Peptide; responsible for luteal surge (driven in part by LH-->testosterone -->estradiol -->LH positive feedback); results in ovulation (follicle bursting) - releasing egg into fallopian tube/oviduct
Homologous chromosomes line up w/ attachment of spindle fibers/microtubule polymers to centromeres via kinetochores; identical in appearance under light microscope to metaphase of mitosis
Smaller - more water soluble short - chain FAs go directly to bloodstream at villi capillaries

3. signal transduction occurs by 2 paths
1) by integral ion channels 2) transmitted by second messenger system
Protein digestion begins in stomach; low pH denatures proteins - kills bacteria; mixes - stores food and destroys it to chyme (BOLUS-->CHYME)
vitreous humor - retina - fovea
Ventrally (picture skeletal vertebrae)

4. overall - fatty - prot - rich food in duod causes
Lysosome
Arrested at primary oocyte; hypothalamus GnRH->FSH released at puberty stims granulosa cell development; granulosa secrete zona pellucida = primary follicle
Amino acid monomers - di - tri absorbed by symport at enterocyte; each AA has slightly diff mechanism; from entero - AAs enter bloodstream where they are taken up by all cells of the body - esp the liver by active or facilitated transport (NEVER PASS
Gastric inhibitory pep; increase of pancreatic - enz activating enzymes (which cleaves zymogens like trypsinogen); increased gall bladder contraction; decreases stomach mobility

5. in mammals - gastrulation involves formation of the
Testosterone and estradiol
Interneurons working to integrate signals received from the peripheral nervous system (sense organs)
Primitive streak - which consists of cells of the MESODERM ****
Glucose = aldose fructose = ketose

6. signal transduction occurs only in
Eukaryotes
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle
Secreted by delta cells of Islets of langerhans; inhibits insulin and glucagon; slows digestion
Membrane - bound - endocytosed bodies

7. What if large intestine isn't working well
Lower blood pH
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals
Determined by whether in front of or behind the lens
Follicular phase: primary - secondary - ovulation (1 week) luteal phase: ovulation - thickening of uterine lining w/corpus luteum secretion - corpus luteum degrades (2 weeks) flow: shedding of uterine lining (4 days)

8. Meiosis II: EQUATIONAL DIVISION
Prophase II: no crossing over b/c there are no homologous chromosomes; nuclear envelope dissolves Metaphase II: chromosomes line up at metaphase plate Anaphase II: sister chromatids separate - migrate to opp poles Telophase II: nuclear envelope reap
Mouth - esophagus - stomach - duodenum - jejunum - ileum - ascending colon - transverse colon - descending colon - sigmoid colon - rectum - anus
Direction of differentiation
Zygote (fertilization in fallopian tubes); morula (up to 8 cells - undifferentiated ie totipotent); blastocyst (4+ days - implants into uterus; HCG secretion stims corpus luteum; gradually placenta replaces HCG as estrogen/progest source; cells not t

9. What is a normal blood glucose range
= catecholamines; fight/flight; vasoconstrictors of internal organs - skin; vasodilators of skel musc; also considered stress hormones; epinephrine - norepinephrine
Night vision
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins
90-140 mg/dl

10. What do villli do
Comes into play in the large intestine - where vitamin b12 is absorbed w/help of E. coli; thus; must travel thru bloodstream to large intestine
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
REABSORPTION: draws off water and ions - increases osmolarity of the medulla while slightly lowering osmolarity of the filtrate -->medulla must have hi osmolarity in order to concentrate urine at collecting duct (final step in nephron)
Has memb - bound organelles - etc...

11. The apical side of the villi...
Most absorption occurs in sm intestine
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
Faces the lumen
Epithelial tissue near semniferous tubules

12. smooth ER main function
Needs time for bile - lipase - micelle migration - enterocyte uptake
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)
Interstitial fluid (eg prostaglandins - cytokines)
Synthesizes lipids (including steroids); detoxifies drugs; is continuous with lumen

13. Some PNS nerves are found in brain - spinal cord
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord
Result is proton secreted into lumen - bicarbonate into interstitial fluid (diffuses into blood); result is also increased blood pH and decreased pH stomach
Eg spinal nerve - cranial nerve; Not All Nervous Tissue In Brain - SC Is CNS Tissue
Growth 1 (G1) phase: STRUCTURAL ProteinS - ENZYMES; This is a very active period - where the cell synthesizes its vast array of proteins - including the enzymes and structural proteins it will need for growth. In G1 stage each of the chromosomes cons

14. examples of different cavities... (compartments for viscera)
***starting with adipose tiss: FFAs are transported in the blood by albumin (major component of blood plasma); one albumin typically carries three fatty acid molecules but can hold up to 30 FAs
Break down TAGs to monoglycerides and free fatty acids
The renal corpuscle
pericardial cavity - pleural cavity (contains lungs) - peritoneal cavity (abdominal)

15. The path from blood plasma to urine

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

16. Between meals most fats appear in blood as
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc
Pepsin - secreted by chief cells in the stomach epithelial lining and active at low pH - breaks down proteins to polypeptides. Protein hydrolysis is aided by the highly acidic environment (hi gastric acid from parietal cells). Polypeptides are squirt
Chyme (by combined activity of exocrine glands)
Ups bicarbonate secretion by pancreas; raises pH to 6.0

17. Embryology
It is the animal counterpart of starch; it is more highly- branched - thus releases more glucose monomers upon repeated hydrolysis than starch
Lower blood pH
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals
Zygote - morula (first four days) - blastocyst (4 day+; implants in uterine lining) - gastrula (2 week) - neurula (3 week)...

18. zygotic life cycle
(haploid organism) many fungi and protozoa; individuals are typically haploid; fertilization may occur with immediate meiosis back to haploid state
Hormones --->stimulate exocrine glands - acetylcholine (increases all secretion of gastric pits) - gastrin (from G cells) - histamine (increases HCl secretion of parietals) ...Ach increases all secretions; gastrin increases gastric acid (parietal cel
REABSORPTION: draws off water and ions - increases osmolarity of the medulla while slightly lowering osmolarity of the filtrate -->medulla must have hi osmolarity in order to concentrate urine at collecting duct (final step in nephron)
Corpus luteum; secretes estradiol - progesterone throughout pregnancy OR if no pregnancy - for about 2 weeks (till menstruation = shedding of uterine lining)

19. 90% digestion - absorption occurs in...
Pancreas; active at sm intestinal pH; hydrolyzes peptide bonds of (pepsin - digested) peptides
Inner lining of blood vessels
Night vision
Small intestine; duodenum is smallest and does most DIGESTION; jejunum is medium and does most ABSORPTION; ileum is biggest and does most absorption along with jejunum

20. Glucose is a .... sugar; fructose is a .... sugar
Peptide; prolactin promotes milk production; prolactin release is stimulated by act of suckling - which in turn inhibits menstrual cycle
Oxytocin and ADH (aka vasopressin)
Thru tight junctions by favorable osmotic gradient
Glucose = aldose fructose = ketose

21. FSH - LH - HCG - inhibin are...
Determined by whether in front of or behind the lens
Organs
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
Peptides

22. light detection via GPCRs
Sensory (afferent - dorsal) - motor (efferent - ventral)
Photon (hv)- rhodopsin - conformation change - GPCR- Na less permeable - hyperpolarized rod cells - generates AP= photobleaching at visible light wavelengths (390-700nm)
Visceral layer= parietal layer; serous membrane is the container of the coelom/peritoneal cavity
All carbs absorbed at enterocytes are carried to liver by portal vein

23. Thus inhibiting parietal cells could do What to blood pH
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP
(haploid organism) many fungi and protozoa; individuals are typically haploid; fertilization may occur with immediate meiosis back to haploid state
Lower blood pH
Small intestine; duodenum is smallest and does most DIGESTION; jejunum is medium and does most ABSORPTION; ileum is biggest and does most absorption along with jejunum

24. food in duod stims release of gastrointestinal hormones
Gall bladder - pancreatic secretions increase - arrive via ampulla of vater (duct glands); insulin secretion increases (fed state; ductless glands)
Facilitated diffusion from hi to lo conc
Bacterial flagellin: hollow filament (not microtub); euk: 9+2 microtubule w/dynein bridges
Salivary amylase (weak); sm intest amylase (breaks down large polysaccharides)

25. hypothalamus - AP - ACTH - cortisol release from adrenal cortex
Gastrulation occurs: formation of three primary germ layers = differentiation
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose
Micelles; micelles transport lipase products to enterocytes for absorption at brush border
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc

26. What Changes - Doesn't Change as a result of movement of molecules across membranes in the proximal tubule
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
Changes: volume of filtrate does not change: osmolarity of filtrate --->reabsorbed ions like sodium carry water across membrane
Glands w/ducts: Exocrine glands
Increases surface area of food ball (bolus)

27. almost all cells can store Some glycogen - but...
After morula - with blastocyst (+8 cell count)--->totipotent to embryonic stem cell and so on
Formed in kidney (nephron) - sent thru renal pelvis - down ureter to bladder - drained by urethra'
Steroid; target tissue is distal convoluted tubule of nephron and collecting duct; increases blood mineral concentration; potassium - protons secreted (blood pH increases); sodium - chloride reabsorbed (BP increases)
Only musc and esp ** liver can store large amounts

28. sporic life cycle
Beta cells
Tight regulation of parietal cells needed b/c gastric acid secretion is E- intensive; parietal cells are hi in mitochons
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae
(diploid and haploid individuals = ALTERNATION of GENERATIONS) a fusion of gametic and zygotic life cycles

29. important because in meiosis germ - line cells begin as 46 2N w/ 23 pairs of homologous chromosomes which are replicated in S phase of interphase to 23 pairs of sister chromatids = still 46 2N
(haploid organism) many fungi and protozoa; individuals are typically haploid; fertilization may occur with immediate meiosis back to haploid state
Growth 1 (G1) phase: STRUCTURAL ProteinS - ENZYMES; This is a very active period - where the cell synthesizes its vast array of proteins - including the enzymes and structural proteins it will need for growth. In G1 stage each of the chromosomes cons
Urine enters kidneys via artery - to arteriole - capillary bed - glomerulus - Bowman's capsule - proximal tubule - loop of henle (concentrates medulla) - distal tubule - collecting tubule - collecting duct (renal pyramids) - renal calyx - renal pelvi
Drugs - toxins - bile pigments (color the urine) - uric acid - antibiotics

30. Cell bodies of SYMP postganglionic neurons lie far from effector...
Eg spinal nerve - cranial nerve; Not All Nervous Tissue In Brain - SC Is CNS Tissue
Testosterone upon stim by LH
Glucocorticoid (cortisol); mineralocorticoid (aldosterone)
Within the paravertebral ganglion - running parallel to spinal cord

31. peroxisome is derived from this
Peptide; prolactin promotes milk production; prolactin release is stimulated by act of suckling - which in turn inhibits menstrual cycle
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots
ER
1) by integral ion channels 2) transmitted by second messenger system

32. insulin secreted by
Beta cells
Glucose
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
1) by integral ion channels 2) transmitted by second messenger system

33. A contracted iris occurs with what kind of stimulation
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome
Sympathetic: dilates pupil (for night hunting)
Many modern drugs are ligands for GPCRs
Neurons may perform one of three functions....

34. On what surface of the retina is the eye most sensitive
Contains hydrolytic enzymes; thus - digests endocytosed substances; derived from golgi
Fovea (highest amount of cones)
Peptide; stims growth of nearly all cell of body; all other anterior pituitary horms have specific targets; upregulates anabolic pathways; use of fat for energy goes up (fat - burning); increases AA transport across cell membrane (nutrient uptake)
Ganglion

35. At post - two weeks ovulation
'Increased absorptive area is useful because digested nutrients (including sugars and amino acids) pass into the villi through diffusion - which is effective only at short distances. In other words - **increased surface area (in contact with the flui
At the collecting duct: becomes more permeable to water which passively diffuses *into the medulla* concentrating the urine
Carry signals to musc OR Gland
Corpus luteum degrades into corpus albicans

36. STOMACH: no absorption
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
Stores blood: when expanded liver serves as blood reservoir for body - filters blood: Kupfer cells phagocytize bacteria picked up from intestines - destroys bad RBCs: also done by Kupfer cells - detoxifies blood: detoxified chemicals are excreted eit
Protein digestion begins in stomach; low pH denatures proteins - kills bacteria; mixes - stores food and destroys it to chyme (BOLUS-->CHYME)
Gall bladder - pancreatic secretions increase - arrive via ampulla of vater (duct glands); insulin secretion increases (fed state; ductless glands)

37. components of interstitial fluid
Glycosaminoglycans - prots - AAs - lipids
Apoproteins attach to outside of globules; these move to Golgi and are released into interstitial fluid via exocytosis as chylomicrons --->most go to lacteal system
Interneurons working to integrate signals received from the peripheral nervous system (sense organs)
Nitrogen

38. FLAT PG: FSH
Nourishes follicle growth; stimulates granulosa cell growth around primary oocyte at puberty = primary follicle; also - stimulates Sertoli cells in males
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)
- parietal cells (**oxyntic= hi oxygen consumption - hi E??): have hi conc mito; need lots of energy to create proton gradient; thus - responsible for extremely harsh pH conditions in stom; denaturing conditions - chief cells (peptic): synthesize pep

39. Where is bile produced
Normally contracted
via symport - secondary transport (ie by pre - established - ATP- intensive) with Na gradient into enterocyte......with no Na gradient (ie without ATP) carbohydrate monomers could not be transported in
In liver (RBC recycling of heme); stored in gall bladder; released via cystic duct to common bile duct (shared w/liver); common bile duct joins up with panc duct...everything feeds into the sm intest at the ampulla of vater**
Apoproteins attach to outside of globules; these move to Golgi and are released into interstitial fluid via exocytosis as chylomicrons --->most go to lacteal system

40. ligands are the messenger compounds that target secondary messenger systems on effectors
Arrested at primary oocyte; hypothalamus GnRH->FSH released at puberty stims granulosa cell development; granulosa secrete zona pellucida = primary follicle
Comes into play in the large intestine - where vitamin b12 is absorbed w/help of E. coli; thus; must travel thru bloodstream to large intestine
Many modern drugs are ligands for GPCRs
Lower blood pH

41. mucus cells line the stomach...
Below hypothalamus
Moves down thru esophageal sphincter
- parietal cells (**oxyntic= hi oxygen consumption - hi E??): have hi conc mito; need lots of energy to create proton gradient; thus - responsible for extremely harsh pH conditions in stom; denaturing conditions - chief cells (peptic): synthesize pep
Contain rough ER and Golgi to make mucous; mucous is full of **glycoprots (sticky) and electrolytes*; protects epithelial tiss of stomach from low pH and lubricates stomach

42. Induction affects...
Fallopian tubes
Faces the lumen
Direction of differentiation
Serous membrane (slick - reducing friction) that forms lining of the coelom --> secretes lubricating fluid

43. What is endothelium?
Which is why lactase - maltase - dextrinase - sucrase are on brush border
Combined via conjunction of pancreatic duct and common bile duct; common bile duct originates at **cystic duct where gall bladder and liver secretions combine ..cystic duct+common bile duct+pancreatic duct --->into duodenum
Estrogen: steroid; stims LH in luteal surge; causes growth of female sex organs progesterone: prepares/maintains uterus for pregnancy
Inner lining of blood vessels

44. physiology of gall bladder - liver and pancreatic secretions
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
Combined via conjunction of pancreatic duct and common bile duct; common bile duct originates at **cystic duct where gall bladder and liver secretions combine ..cystic duct+common bile duct+pancreatic duct --->into duodenum
Called a tract in the CNS; bundling together of axons/dendrites thru which many diff signals pass; many many neurons are bundled together into a single nerve
Peristalsis (esophagus) and segmentation (bi - directional=mixing)

45. keep in mind that enterocyte is like a regular euk cell
Which is why lactase - maltase - dextrinase - sucrase are on brush border
Ups bicarbonate secretion by pancreas; raises pH to 6.0
Has memb - bound organelles - etc...
Mostly reabsorbed to liver

46. What force is acting upon chyme to move it forward down sm intestine
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)
Comes into play in the large intestine - where vitamin b12 is absorbed w/help of E. coli; thus; must travel thru bloodstream to large intestine
Peristalsis (esophagus) and segmentation (bi - directional=mixing)
The wall of the body or of a body cavity or hollow structure

47. Local vs long - distance mediators
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases
Water flows from the tubule - concentrating the filtrate - raising BP
Paracrine (local) - endocrine (longer distance)
Smaller - more water soluble short - chain FAs go directly to bloodstream at villi capillaries

48. What is the path of a sound wave that enters the ear?
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)
Water flows from the tubule - concentrating the filtrate - raising BP
Outer ear= pinna (auricle)- external auditory canal - eardrum (tympanic membrane) inner ear= malleus - incus - stapes - ...oval window - cochlea - where sound is transduced into neural signal...enters cochlea at scala vestibuli - where pressure chang

49. What is the net effect of the loop of Henle
Vitamin K - b12 - thiamin - riboflavin
Glucose and ketone bodies (not from glycogen stores)
Secrete intrinsic factor; important for absorbing vitamin B12 in sm intest
REABSORPTION: draws off water and ions - increases osmolarity of the medulla while slightly lowering osmolarity of the filtrate -->medulla must have hi osmolarity in order to concentrate urine at collecting duct (final step in nephron)

50. cholinergic receptors: NICTONIC and MUSCARINIC Nicotinic: neuromuscular effectors (ionotropic) Muscarinic: PARA effectors (GPCRs) Adrenergic: SYMP effectors (GPCRs)
Liver is the control center for blood glucose; is fed by portal vein from sm intest
Lots of energy; eg neurons have hi glucose need for 3Na out 2K in ATPase; stomach epithel tiss needs E for parietal cells to pump protons into lumen and bicarbonate into blood
Hypothalamus --->AP--->target tissues eg TSH - thyroid - T3/T4 release - increase basal metabolic rate
**only para effectors have muscarinic receptors; symp effectors are adrenergic (epi - norepi); **neuromuscular junction uses nicotinic receptors