Select which of the following statements are true about ions:
a positively charged particle and a negatively charged particle attract each other
two negatively charged particles attract each other
a positively charged particle and a negatively charged particle repel each other
two positively charged particles attract each other

Charges of opposite sign attract one another

Charges of the same sign repel each other

so statement 1 and 4 is true.

regents of the university of california v. bakke, 438 u.s. 265 (1978), was a landmark decision by the supreme court of the united states. it upheld affirmative action, allowing race to be one of several factors in college admission policy.

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.