Question: Review the images and text about stages 13 (about 32 days) and 23 (about 53-58 days), and compare the limb development
at these stages. Answer: In stage 13, all four limb buds are present. In stage 13, the upper limb buds resemble flippers. In stage 23, the upper limb shows well-formed arm, elbow, wrist, and fingers. In stage 23, the lower limb shows well-formed toes, feet, and knees.
n stage 13, all four limb buds are present. In stage 13, the upper limb buds resemble flippers. In stage 23, the upper limb shows well-formed arm, elbow, wrist, and fingers. In stage 23, the lower limb shows well-formed toes, feet, and knees.
Mantle plumes that form hotspots are thought to be relatively stationary whereas the overlying tectonic plates typically are not. Thus, as a plate moves over the location of a plume eruption, it carries successively older volcanoes with it.
This involves selectively breeding two or more populations of a species or subspecies with desirable traits that are wanted by the humans. The offspring of the populations will bear the desired traits from the population. Breeding can be done over generations. An example is the breeding a cattle population that is resistant to drought and another that produces more milk. The filial generations will bear both traits.
