Embryology and Evolution

A. Describe how embryological similarities across vertebrate species give some evidence of those species having descended from a common ancestor. B. Describe how biochemical analyses have helped provide support for a generalized theory of evolution. Provide references

Behaviour of Fish Experiment

Two recently discovered fish species, both found in waters off a small island. The two species are very similar in general structure, but there are two key differences between them. In species A, males are brightly patterned with blue, red, and purple scales, whereas the females are drab, and males are much larger than females. In species B, males and females are the same size, and both are a dull brown color that blends in with the sandy bottom. You have decided to do an in-depth study of these two species, but to get your research grant, you must first develop some predictions about what you will find. What differences in behavior do you predict (list as many as you can think of)? How migh... click for more

Ecology Experiments Involving Habitat and Species Analysis

A. An ecologist studying desert plants performed the following experiment. She staked out two identical plots that included a few sagebrush plants and numerous small annual wildflowers. She found the same five wildflower species in similar numbers in both plots. The she enclosed one of the plots with a fence to keep out kangaroo rats, the most common herbivores in the area. After two years, four species of wildflowers were no longer present in the fenced plot, but one wildflower species had increased dramatically. The unfenced control plot had not changed significantly in species composition. Using the concepts discussed in the chapter, what do you think happened? B. Imagine that you hav... click for more

Doctors and nurse are constantly exposed to many infectious patients. Why are doctors and nurses not continuously ill?

A. Doctors and nurse are constantly exposed to many infectious patients. Why are doctors and nurses not continuously ill? B. Why is the lymphatic system a “highway” for the spread of certain metastatic cancers? C. Erythrocyte-structure and function Erythrocytes (mature red blood cells) lose their mitochondria, nucleus, ribosomes and many cytoplasmic enzymes during development. How does this affect the shape of the cell? How does its structure relate to its function? D.Humoral versus cell mediated immunity Describe humoral immunity and cell-mediated immunity. Include in your answer the types of immune cells involved in each, the location of antibodies and receptors that bind foreig... click for more

Bio Question

Birds and mammals have a four-chambered heart, with two ventricles and two atria, but other modern reptiles have a three-chambered heart, with just one ventricle. Paleontologists debate whether dinosaurs had a typical “reptile-like” heart or a “birdlike” heart. Long-necked sauropod dinosaurs could have had unusual circulatory demands because their head may have been raised far above their heart. The farther the head is above heart, the greater the systolic pressure needs to be for blood to reach the brain. For example, the long-necked dinosaur Brachiosaurus may have carried it head as much as 6 m (20 feet) above its heart. It is estimated that such an anatomy demanded a systolic blood pressu... click for more