21. formed from both endoderm and ectoderm: a. pharathryoid glands

b. pharyngeal groove

c. pharyngeal pouch

d. thymus

e. tympanic membrane

22. nephron development begins with migration of cells from around uretric bud tip to region of the uretric stalk. these cells differentiate to form the

a. renal cortex

b. renal vesicle

c. renal pyramid

d. penal papilla

e. renal pelvis

this protocol describes a detailed procedure for intracellular flow cytometry staining.

scientists have discovered that hiv does not cause aids by the virus's direct effect on the host's immune cells, but rather through the cells' lethal influence on one another. researchers from the gladstone institutes have revealed that hiv does not cause aids by the virus's

genetic variation will increase because of a new habitat and food source.

explanation: