An ecosystem is most likely to return to its original condition after which of these occurs? a new predators are introduced to control a pest population. b a marsh is filled in to make space for a new parking lot. c tall prairie grass burns after being struck by lightning. d flood waters erode the banks of a narrow stream.

a new predators are introduced to control a pest population.

Explanation:

An ecosystem is a biotic community in which the living beings interact with their non-living physical environment and among themselves so as to sustain their lives.

Among the options given the ecosystem is most likely to return to its' original condition after pest infestation when new predators are introduce to control these pests. The ecosystem will come back to the stable state after the pests are irradicated.

fertilization, pictured in figure 24.23a is the process in which gametes (an egg and sperm) fuse to form a zygote. the egg and sperm each contain one set of chromosomes. to ensure that the offspring has only one complete diploid set of chromosomes, only one sperm must fuse with one egg. in mammals, the egg is protected by a layer of extracellular matrix consisting mainly of glycoproteins called the zona pellucida. when a sperm binds to the zona pellucida, a series of biochemical events, called the acrosomal reactions, take place. in placental mammals, the acrosome contains digestive enzymes that initiate the degradation of the glycoprotein matrix protecting the egg and allowing the sperm plasma membrane to fuse with the egg plasma membrane, as illustrated in figure 24.23b. the fusion of these two membranes creates an opening through which the sperm nucleus is transferred into the ovum. the nuclear membranes of the egg and sperm break down and the two haploid genomes condense to form a diploid genome.

explanation:

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.