<span>The structure of the feet and legs varies greatly among frog species, depending in part on whether they live primarily on the ground, in water, in trees or in burrows. Frogs must be able to move quickly through their environment to catch prey and escape predators, and numerous adaptations help them to do so. Most frogs are either proficient at jumping or are descended from ancestors that were, with much of the musculoskeletal morphology modified for this purpose. The tibia, fibula, and tarsals have been fused into a single, strong bone, as have the radius and ulna in the fore limbs (which must absorb the impact on landing). The metatarsals have become elongated to add to the leg length and allow the frog to push against the ground for a longer period on take-off. The illium has elongated and formed a mobile joint with the sacrum which, in specialist jumpers such as ranids and hylids, functions as an additional limb joint to further power the leaps. The tail vertebrae have fused into a urostyle which is retracted inside the pelvis. This enables the force to be transferred from the legs to the body during a leap </span>
<span>The muscular system has been similarly modified. The hind limbs of ancestral frogs presumably contained pairs of muscles which would act in opposition (one muscle to flex the knee, a different muscle to extend it), as is seen in most other limbed animals. However, in modern frogs, almost all muscles have been modified to contribute to the action of jumping, with only a few small muscles remaining to bring the limb back to the starting position and maintain posture. The muscles have also been greatly enlarged, with the main leg muscles accounting for over 17% of the total mass of the frog.</span>
Answer:
The correct answer is option b, that is, four-field approach.
Explanation:
Anthropology refers to the study of human beliefs, behavior, and adaptations. In order to completely comprehend any aspect of human behavior, the field of anthropology adopts a four-field approach. The four sub-disciplines of anthropology are archaeology, cultural anthropology, biological anthropology, and linguistic anthropology.
In archaeology, materials are used generally from past cultures, in order to understand and illustrate human behavior and adaptive strategies via time. Biological anthropology refers to the study of humans as biological species, the research areas comprise diversity in modern human populations, human evolution, and medical anthropology.
The cultural anthropology explores patterns of behavior and belief in historical and contemporary cultures all over the globe. The linguistic anthropology studies and documents languages in terms of acquisition, structure, and use in the transmission of culture. As can be seen that each of the sub-disciplines focuses on distinct characteristics of human adaptation, however, when taken together in a four-field approach it offers a powerful tool for gaining a complete understanding of any aspect of human behavior.
<span>10% rule (efficiency between trophic levels): limits how long an ecosystem's food chain can be
Predator/prey
cost benefit analysis (i.e. foraging) -- cost is risk of being eaten or
killed along the way, benefit is energy/nourishment obtained: limits
distribution of predator v. prey
Immigration/Emigration with other populations and ecosystems
Island
biogeography: size of land and distance from another
population/ecosystem (mainland): limits population size and variability
on island</span>
I believe it is the nucleus.
