Answer:
The third diagram shows Refraction of waves.
Explanation:
Refraction is a phenomenon, which occurs in a wave when it travels from one medium to another medium, and during Refraction there is slight or greater change in direction of the wave.
hence, the wave will pass through the surface and displaces from its actual path.
that's why the most appropriate diagram showing Refraction is third one ( c ) .
Answer:
The correct answer is D. Reduced levels of circulating estrogens.
Explanation:
Estrogens prevent the loss of calcium and ensure its proper mineralization, thus preventing the bones from becoming brittle, maintaining the consistency of the skeleton and preventing osteoporosis. Osteoporosis is a skeletal disease in which there is a decrease in bone mass density. Thus, the bones become more porous, the number and size of the cavities or cells that exist inside them increases, they are more fragile, they resist shocks worse and they break more easily. Menopause is the definitive cessation of ovarian function that, externally, results in the disappearance of the menses and usually occurs around 50 years (the interval goes from 45 to 55 years). It is the gradual loss of calcium in the bones, which accelerates in the first years of menopause due to estrogen deficiency. At the beginning of the disease, there are no symptoms and, as it progresses, there is a tendency to suffer fractures, which leads to a decrease in height.
Natural selection is the process by which individuals with characteristics that are advantageous for reproduction in a specific environment leave more offspring in the next generation, thereby increasing the proportion of their genes in the population gene pool over time. Natural selection is the principal mechanism of evolutionary change, and is the most important idea in all biology. Natural selection, the unifying concept of life, was first proposed by Charles Darwin, and represents his single greatest contribution to science.
Natural selection occurs in any reproducing population faced with a changing or variable environment. The environment includes not only physical factors such as climate or terrain, but also living factors such as predators, prey, and other members of a population.
Mechanism of Natural Selection
The mechanism of natural selection depends on several phenomena:
• Heredity: Offspring inherit their traits from their parents, in the form of genes.
• Heritable individual variation: Members of a population have slight differences among them, whether in height, eyesight acuity, beak shape, rate of egg production, or other traits that may affect survival and reproduction. If a trait has a genetic basis, it can be passed on to offspring.
• Overproduction of offspring: In any given generation, populations tend to create more progeny than can survive to reproductive age.
• Competition for resources: Because of excess population, individuals must compete for food, nesting sites, mates, or other resources that affect their ability to successfully reproduce.
Given all these factors, natural selection unavoidably occurs. Those members of a population that reproduce the most will, by definition, leave more offspring for the next generation. These offspring inherit their parents' traits, and are therefore also likely to succeed in competition for resources (assuming the environment continues to pose the same challenges as those faced by parents). Over several generations, the proportion of offspring in a population that are descended from the successful ancestor

Uloborid spider eggs and spiderlings. In any given generation, populations tend to create more offspring than can survive to reproductive age.
increases, and traits that made the ancestor successful therefore also increase in frequency. Natural selection leads to adaptation, in which an organism's traits conform to the environment's conditions for existence.
Answer:
The answer is D. The loss of biodiversity caused changes to food webs in the turtle ecosystems.
Explanation:
