As red blood cells age . a. they will eventually be excreted by the digestive system b. ATP production increases c. iron will be excreted by the kidneys d. membranes "wear out" and the cells become damaged

a. they will eventually be excreted by digestive system.

Explanation:

The average life span of healthy red blood cells (RBCs) is 120 days. After 120 days, RBCs are transported to spleen which is also known as graveyard of RBCs. In the spleen RBCs are broken into iron and bile pigment by several digesting enzymes. The iron is transported back to the red bone marrow to use it for the formation of new RBCs. The non-iron portion of heme goes through a series of chemical conversions that eventually end up in the large intestine which is what gives feces its characteristic brown color.

her next move would be to use agarose gel electrophoresis to separate the dna molecules of varying length and create a dna fingerprint.

osteogenesis imperfecta (oi) refers to a congenital ailment of bones. in the condition, the bones become brittle or fragile. this ailment is a general result of the defect or mutations in the genes (colia1 or colia2). this mutation results in imperfect collagen formation either in quantity or quality wise.  

there are eight kinds of oi defects, and each kind varies with certain distinctions in symptoms. the usual symptoms include frequent bone fractures, loss of hearing in infants, protruding eyes, discoloration of the white in the eyes, respiratory issues, loosening of the joints, short stature, and other symptoms.