(CNN) -- Here are summaries of five of the biggest cases awaiting rulings by the Supreme Court. Decisions will be released between now and the end of June.
AFFIRMATIVE ACTION: Fisher v. University of Texas at Austin
AT ISSUE: A challenge to the school's race-conscious admissions policies.
THE CASE: Abigail Fisher individually sued the flagship state university after her college application was rejected in 2008 when she was a high school senior in Sugar Land, Texas.
THE ARGUMENTS: Fisher claims she was turned away in part because she is white, despite being more qualified than some minority applicants. The school defends its policy of considering race as one of many factors -- such as test scores, community service, leadership and work experience -- to ensure a diverse campus.
THE OUTCOME: It appears the conservative majority has the votes to strike down the school's policy in some form, and it's a good bet Justice Anthony Kennedy is writing the opinion. His moderate-conservative outlook could mean a limited ruling: striking down this university's efforts but allowing affirmative action to continue in some circumstances.
THE IMPACT: The appeal raises anew thorny, unresolved questions over race and remedies. Justice Elena Kagan did not hear this case because she had dealt with the issue while she was President Barack Obama's solicitor general. That would make a 4-4 tie possible, meaning the university would prevail, but no important precedent would be established. The high court will revisit the issue this fall in a separate appeal on whether Michigan's voter-approved ban on affirmative action is constitutional.
VOTING RIGHTS: Shelby County, Alabama v. Holder; Nix v. Holder
AT ISSUE: The continued use by the federal government of the key enforcement provision of the landmark Voting Rights Act of 1965.
THE CASE: Section 5 gives federal authorities open-ended oversight of states and localities with a history of voter discrimination. Any changes in voting laws and procedures in the covered states must be "pre-cleared" with Washington.
THE ARGUMENTS: The provision was reauthorized in 2006 for another quarter-century, and counties in Alabama and North Carolina subsequently filed suit, saying the monitoring was overly burdensome and unwarranted. All or parts of 16 states are currently covered under the provision. Other states are not covered by the pre-clearance provision even if they, too, might discriminate against minority voters.
In a separate high court case from three years ago, the conservative majority suggested -- but never fully affirmed -- that the continued use of Section 5 may soon be nullified. "Things have changed in the South. Voter turnout and registration rates now approach parity," Chief Justice John Roberts wrote in 2009. "Past success alone, however, is not adequate justification to retain the pre-clearance requirements. The Act imposes current burdens and must be justified by current needs."
THE OUTCOME: The conservative majority again appears to have the votes to strike down or severely gut Section 5. The court could then encourage Congress and the Obama administration to fashion a new enforcement policy that would meet constitutional scrutiny.
THE IMPACT: The high court's decision to accept these appeals for a full review came in a presidential election year that incorporated newly redrawn voting boundaries, based on the updated census. This ruling would likely impact next year's mid-term elections.
SAME-SEX MARRIAGE (Two separate issues)
Defense of Marriage Act: Windsor v. U.S.
AT ISSUE: Whether the federal Defense of Marriage Act violates equal protection guarantees in the Fifth Amendment's due process clause as applied to same-sex couples legally married under the laws of their states.
THE CASES: Edith "Edie" Windsor was forced to assume an estate tax bill much larger than those other married couples would have to pay. Because her partner was a woman, the federal government did not recognize the same-sex marriage legally, even though their home state of New York did. The law known as DOMA defines marriage for federal purposes as a union between a man and woman only.
The legal issue is whether the federal government can deny tax, health and pension benefits to same-sex couples in states where they can legally marry. Federal appeals courts in New York and Boston struck the benefits provision, with judges in one case saying, "If we are right in thinking that disparate impact on minority interests and federalism concerns both require somewhat more in this case than almost automatic deference to Congress' will, this statute fails that test."
THE ARGUMENTS: Federal courts have not yet addressed the federal law's other key provision: states that do not allow same-sex marriages cannot be forced to recognize such unions performed in other states. Traditionally, marriages in one jurisdiction are considered valid across the country.
THE OUTCOME: There are many options. The simplest solution would be for the court to dismiss the appeal on standing grounds, or who has a right to bring a case before the court. That would leave the lower courts or the other branches to decide who would defend DOMA. But if the court strikes down the benefits provision -- the only part of DOMA at issue here -- that would create many unanswered questions, especially in those states that currently ban gay marriage.
THE IMPACT: The Obama administration, in a rare move, has refused to defend a federal law in court. That left the GOP-controlled House of Representatives to file the legal appeals to the high court, creating unusual questions about standing.
California ballot measure (Proposition 8): Hollingsworth v. Perry
AT ISSUE: Whether the Constitution's 14th Amendment guarantee of "equal protection" prevents states from defining marriage as being only between one man and one woman.
THE CASE: The "Prop 8" case, as it has become known, has been down a complicated legal road. California's Supreme Court ruled same-sex marriages were legal in 2008. After the statewide ballot measure banning them passed with 52% of the vote later that year, gay and lesbian marriages were put on hold. Then a federal appeals court in San Francisco ruled the measure unconstitutional. In its split decision, the panel found Proposition 8 "works a meaningful harm to gays and lesbians" by denying their right to civil marriage.
THE ARGUMENTS: California is the only state that accepted, then revoked, same-sex marriage as a legal right. The measure's supporters asked the justices to preserve the will of the voters in this politically charged social issue. Opponents of Prop 8 seek a court-ordered expansion of the "traditional" views of marriage.
THE OUTCOME: With so many options, the simplest one would be to "DIG" it -- dismiss the case as "improvidently granted," meaning the larger constitutional issues would not be settled, at least now. That could throw the case back to the lower courts to sort out the jurisdictional issues and perhaps allow another voter referendum next year on gay marriage. A sweeping ruling on whether same-sex marriage is a fundamental constitutional right seems unlikely.
THE IMPACT: Currently, same-sex marriage is allowed in nine states and the District of Columbia. Rhode Island, Delaware and Minnesota's recently passed laws take effect this summer. It is estimated about 120,000 legally married same-sex couples live in the United States.
Another seven or so states recognize civil unions or broad domestic partnerships, providing state-level spousal rights to same-sex couples. Obama, who previously opposed same-sex marriage, said he now supports it.
PATENTS - Association for Molecular Pathology v. Myriad Genetics
AT ISSUE: Whether human genes are patentable. Can "products of nature" be treated the same as "human-made" inventions and held as the exclusive intellectual property of individuals and companies?
THE CASE: A Utah-based company was sued over its claim of patents on two human genes. Myriad Genetics isolated and identified related types of biological material, BRCA-1 and BRCA-2, whose mutations are linked to increased hereditary risk for breast and ovarian cancer. With its development of synthesized gene clones, Myriad is the only company that can perform tests for potential abnormalities.
THE ARGUMENTS: On one side, many scientists and companies argue that patents encourage medical innovation and investment that save lives. On the other, patient rights groups and civil libertarians counter that the patent holders are "holding hostage" the diagnostic care and access to information available to high-risk patients.
The patent system was created more than two centuries ago with a dual purpose: offering temporary financial incentives for those at the ground floor of innovative products and ensuring that one company does not hold a lifetime monopoly that might stifle competition and consumer affordability.
THE OUTCOME: The court signaled during oral arguments it might strike a middle ground by blocking companies from patenting "natural" genes themselves but allowing them to patent the discovery of something valuable about the gene, such as a test to detect breast cancer.
The high court has long allowed patent protection for the creation of a new process or use for natural products. Whether "isolating" or "extracting" genes themselves qualifies for such protection is now the issue.
THE IMPACT: The issue gained greater public attention when actress Angelina Jolie announced this month she had undergone a double mastectomy after taking the BRCA tests from Myriad. In what could be a guide to the justices in Myriad, the high court last term rejected a patent claim on a doctor's medical diagnosis of a patient's reaction to a drug.