National parks can be a double-edged sword because . -the crowds of people that are attracted can disrupt the ecosystem
-it often costs too much to visit them
- the parks are not necessarily interesting
-they do not generate any revenue

In the african savanna,more wildebeests are born than the environment can support. which is most likely to happen over a period of years as a result

This is a situation in which genes are attached to an organism's sex chromosomes; the sex of an organism influences the expression of a gene.

Define the apical impulse and describe its normal location, size, and duration. which abnormal conditions may affect the location of the apical impulse? explain the mechanism producing normal first and second heart sounds. describe the effect of respiration on the heart sounds. describe the characteristics of the first heart sound and its intensity at the apex of the heart and at the base. describe the characteristics of the second heart sound and its intensity at the apex of the heart and at the base.