In ferns the spores develop on a. the tip of the gametophyte. b. the underside of the gametophyte. c. the roots of the gametophyte. d. the underside of the sporophyte.

The correct answer is option D-the underside of the sporophyte.

Explanation:

Ferns are pteridophytes which evolved earlier than the flowering plants. They do not produce seeds and reproduce through spores.

These spores are usually present on the underside of fern leaf also called "fronds" in sporophytic structures called sori. When these spores are ripened they are released from the capsule which germinates to produce prothallus, a gametophyte from which gametes are produced.

Thus, option D-the underside of the sporophyte is the correct option.

this protocol provides a detailed procedure for total protein extraction for western blot analysis from achieved samples following trizol isolation of rna.

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.