Which scenario would be most appropriate to study using a natural experiment? * the effects of an herbicide on human health the influence of sleep on exam performance the effects of an earthquake on blood pressure

C. the effects of an earthquake on blood pressure

Explanation:

Natural experiments are observational studies in which participants are randomly assigned to groups that allow the researcher to draw causal relationships between an event and a factor. These experiments are used in studies where it would be unethical and unacceptable to subject human participants to such conditions. It is most times applied in epidemiological studies.

Since the researcher cannot control an earthquake which is a natural occurrence, this can be rightly described as a natural experiment. Controls are not used in this type of experiment.

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:

carbon

explanation: