PLEASE HELP EMERGENCY PLEASE!! How does the respiratory system keep your body alive? *

by supporting and protecting your organs

by helping you to produce hormones to help your body function

by transmitting signals between different parts of the body

by taking in oxygen and cleaning out waste gases like carbon dioxide

(This is 7th grade science)

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Which statement best describes a keystone species? o a. it has littlelmenetic variation. it has an extremely high population. 0 b. 0 c. it remains unaffected by all environmental changes. od. it has a strong influence on the ecosystem. 0 e. it's the first species to populate a new ecosystem.

According to this food web which of the following would be considered primary consumers