MCAT Review Cards - Biology

Question 1

what is the funtion of the collecting duct

Answer 1

has a variable permeabiity , which allows reabsorption of the right amout of H2O depending on the body’s needs.

Question 2

Allele

Answer 2

a variant form of a gene located at the same position on a chromosome.

Question 3

Amine hormones

Answer 3

small hormones derived from the amino acid tyrosine and tryptophan

Question 4

Total Lung Capacity

Answer 4

amt of air in the lungs after taking the deepest breath possible

Question 5

Muscle relaxation

Answer 5

Occurs when Ach is degraded by acylcholinesterase, terminating the signal and allowing Ca2+ to return to the sarcoplasmic reticulum

Question 6

Cell Differentitation

Answer 6

At the G1 check point, cells choose whether or not to divide

Question 7

Transduction

Answer 7

transfer of genetic material using a bacteriophage

Question 8

Platelets

Answer 8

aka Thrombocytes are components of blood whose fxn is to react to bleeding from blood vessel injury by clumping thereby initiating a blood clot

Question 9

single twitch

Answer 9

when only one muscle fiber responds to a breif stimulus

Question 10

Transverse Tubule ( T- Tubule)

Answer 10

extensions of the cell mbn that penetrate into the center of the skeletal and cardiac muscle cells

Question 11

Myofibrils

Answer 11

Sarcomeres attached end-to-end

Question 12

Red Skeletal Muscle

Answer 12

are slow-twitch fibers and carry out oxidative phosphylation

Question 13

myocytes

Answer 13

each contain myofibrils

Question 14

Frequency summation

Answer 14

addition of multiple twitches before the muscle has chance to fully relax

Question 15

CCK

Answer 15

Stimulates bile release from the gallbladder, realease of pancreatic juices, promotes satiety

Question 16

Secretin

Answer 16

stimulates the release of pancreatic juices and slows motility

Question 17

creatine phosphate

Answer 17

adds a phosphate to ADP –> atp

Question 18

Cardiac muscle cells

Answer 18

connected with intercalated discs that contain gap junctions

Question 19

Muscle Contraction

Answer 19

begins at the neruomuscular junction , where the efferent neuron releases Ach which binds to receptors on the sarcolemma and causes depolarization.

Question 20

Cell Mediated Cytotoxic immunity

Answer 20

produces an immune response that does not involve antibodies ( involves activation of phagocytes, T-cells, and release of cytokines in response to an antigen)

Question 21

T4

Answer 21

Is a precursor to T3 ; T4 = thyroxine ; T3 = Triiodothyroinine ; regulates metabolism

Question 22

Passive immunity

Answer 22

transfer of antibodies to an indvidual

Question 23

juxtacrine signaling

Answer 23

when a cell signals another cell that is directly adjcent or attached

Question 24

Proximal Convuluted Tubule

Answer 24

site of bulk reabsorption of glucose, amino acids, soluable vitamins, salt, and H2O

Question 25

vasa recta and loop of Henle

Answer 25

flow in opposite directions, creating a coutercurrent mutlipier system that allows maximal reabsoprtion of water

Question 26

Tendons

Answer 26

attach bones to muscles

Question 27

Calcitonin

Answer 27

released by the thyroid gland and builds bone ; Increase Ca2+ in bone, increases Ca2+ excretion from kidneys ; decreases Ca2+ in blood, decreases Ca2+ absorption in gut

Question 28

Thin Skin Epidermis

Answer 28

outer to inner : Strat Corneum, Granulosum, Spinosum, Basale

Question 29

Peptide hormone

Answer 29

hormone that consitsts of amino acids ;

Question 30

Osteon

Answer 30

cheif structural unit of compact (cortical) bone.

Question 31

Cell determination

Answer 31

Committing to become one type of cell, Factors: Cell position in the body, signaling, gene expression

Question 32

GPCR

Answer 32

mbn receptor that transfers a signal from outside the cell to the inside of the cell

Question 33

Hypodermis

Answer 33

lies btwn the dermis and underlying tissues and organs. It consists of mostly adipose tissue , site of storage for body fat

Question 34

Aldosterone

Answer 34

increases Na+ reabsorption in the distal convoluted tubule and collecting duct, increases H2O reabsorption and increase BP

Question 35

Excretory (urine) pathway:

Answer 35

Bowman's space --> Proximal Convluted tubule --> Descending limb loop oof Henle --> ascending limb of the loop of henle --> distal convoluted tubule --> collecting duct --> renal pelvis --> ureter --> bladder --> urethra.

Question 36

Cartilage

Answer 36

connective tissue that is firm but flexible and connects bones together

Question 37

pacreatic acinar cells

Answer 37

fxnal unit of exocrine pancreas. Synthesizes, stores, and scretes digestive enzymes ; Pancreatic juices contain bicarb, amaylase, peptidases, lipase

Question 38

B cells

Answer 38

mature into plasma cells that produce antibodies