PLEASE HELP ME EMERGENCY PLEASE HELP Which of the below best describes the function of the respiratory system?

To circulate nutrients and gases throughout the body.

To bring oxygen into the body and to remove carbon dioxide from the body.

To break down food to glucose molecules that the cells can use.

(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.

Imagine that certain laws of physics could be ignored and you were able to travel vast distances in moments. now imagine that you traveled to an earth-like planet located light-years away that is known to support life. think about what you’ve learned in this unit and make an argument for what you think would be the dominant type of life form on this planet. consider whether a notochord is required for an organism to manipulate its environment and become a dominant creature.

Nucleic acid certain protein cell membranes certain carbohydrates