Las proteínas con estructura cuaternaria se caracterizan porque para su formación se deben unir varias cadenas polipeptídicas y forman una sola molécula, son ejemplo de ellas: I. Cápside del virus de la poliomielitis II. Hexoquinasa III. Hemoglobina IV. Gastrina

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation:

explanation:

on disadvantage of hydroelectric power is the cost. another disadvantage of using hydroelectric power is finding a water source powerful enough to harvest hydroelectric power.

i think its the first one

well for one plants are always the producer, so a is the answer. a wolf is more of the consumer(predator) and the deer is the prey so i know those two are out of the question. also mushrooms are fungi/fungus so a is the producer.