How does the principle of independent assortment apply to chromosomes?

If 2 identical twins marry another set and they both have children. Would their children not only be cousins, but brother and sister? How many chromosomes would a baby with Monosomy disorder have?

Aneuploidy is an abnormal # of chromosomes. What is the difference between male and female chromosomes? When during the cell cycle are chromosomes visible?

What is the name given to the duplicated pair of chromosomes? What is the the exchange of genes between homologous chromosomes called? How many chromosomes are shown in a normal human karyotype?

What is the number of chromosomes in each phase of mitosis? What ways are homologous chromosomes similar? What are chromosomes made of?

Chromosomes are 50% protein and 50% DNA. What is the haploid number of a carrot with 8 chromosomes? Where in the cell are chromosomes located?

When during the cell cycle are chromosomes visible? What are chromosomes made of? Chromosomes are 50% protein and 50% DNA.

What can be used to determine whether a person has inherited the normal number of chromosomes? What is the number of chromosomes in meiosis? What is the difference between male and female chromosomes?

What ways are homologous chromosomes similar? When do chromosomes form 'tetrads'? Chromosomes form tetrads during prophase I.

How many chromosomes would a baby with Monosomy disorder have? Aneuploidy is an abnormal # of chromosomes. What is the the exchange of genes between homologous chromosomes called?

"Franklin seriously realized it would be beneficial to make better use of daylight, but he didn't really know how to implement it," Prerau said. It wasn't until World War I that daylight savings were realized on a grand scale. Germany was the first state to adopt the time changes, to reduce artificial lighting and thereby save coal for the war effort.

Friends and foes soon followed suit. In the U.S. a federal law standardized the yearly start and end of daylight saving time in 1918—for the states that chose to observe it. During World War II the U.S. made daylight saving time mandatory for the whole country, as a way to save wartime resources.

Between February 9, 1942, and September 30, 1945, the government took it a step further. During this period daylight saving time was observed year-round, essentially making it the new standard time, if only for a few years. Since the end of World War II, though, daylight saving time has always been optional for U.S. states.

But its beginning and end have shifted—and occasionally disappeared. During the 1973-74 Arab oil embargo, the U.S. once again extended daylight saving time through the winter, resulting in a one percent decrease in the country's electrical load, according to federal studies cited by Prerau. Thirty years later the Energy Policy Act of 2005 was enacted, mandating a controversial monthlong extension of daylight saving time, starting in 2007.

But does daylight saving time really save any energy? Daylight Saving Time: Energy Saver or Just Time Suck? In recent years several studies have suggested that daylight saving time doesn't actually save energy—and might even result in a net loss.

Environmental economist Hendrik Wolff, of the University of Washington, co-authored a paper that studied Australian power-use data when parts of the country extended daylight saving time for the 2000 Sydney Olympics and others did not. The researchers found that the practice reduced lighting and electricity consumption in the evening but increased energy use in the now dark mornings—wiping out the evening gains. Likewise, Matthew Kotchen, an economist at the University of California, saw in Indiana a situation ripe for study.

Prior to 2006 only 15 of the state's 92 counties observed daylight saving time. So when the whole state adopted daylight saving time, it became possible to compare before-and-after energy use. While use of artificial lights dropped, increased air-conditioning use more than offset any energy gains, according to the daylight saving time research Kotchen led for the National Bureau of Economic Research in 2008.

That's because the extra hour that daylight saving time adds in the evening is a hotter hour. "So if people get home an hour earlier in a warmer house, they turn on their air conditioning," the University of Washington's Wolff said. In fact, Hoosier consumers paid more on their electric bills than before they had made the annual switch to daylight saving time, the study found.

But other studies do show energy gains. In an October 2008 daylight saving time report to Congress, mandated by the same 2005 energy act that extended daylight saving time, the U.S. Department of Energy asserted that springing forward does save energy. Extended daylight saving time saved 1.3 terawatt hours of electricity.

That figure suggests that daylight saving time reduces annual U.S. electricity consumption by 0.03 percent and overall energy consumption by 0.02 percent. While those percentages seem small, they could represent significant savings because of the nation's enormous total energy use. What's more, savings in some regions are apparently greater than in others.

California, for instance, appears to benefit most from daylight saving time—perhaps because the state's relatively mild weather encourages people to stay outdoors later. The Energy Department report found that daylight saving time resulted in an energy savings of one percent daily in the state. But Wolff, one of many scholars who contributed to the federal report, suggested that the numbers were subject to statistical variability and shouldn't be taken as hard facts.

And daylight savings' energy gains in the U.S. largely depend on your location in relation to the Mason-Dixon Line, Wolff said. "The North might be a slight winner, because the North doesn't have as much air conditioning," he said. "But the South is a definite loser in terms of energy consumption.

Daylight Saving Time: Healthy or Harmful? For decades advocates of daylight savings have argued that, energy savings or no, daylight saving time boosts health by encouraging active lifestyles—a claim Wolff and colleagues are putting to the test. "In a nationwide American time-use study, we're clearly seeing that, at the time of daylight saving time extension in the spring, television watching is substantially reduced, and outdoor behaviors like jogging, walking, or going to the park are substantially increased," Wolff said.

But others warn of ill effects. Till Roenneberg, a chronobiologist at Ludwig-Maximilians University in Munich, Germany, said his studies show that our circadian body clocks—set by light and darkness—never adjust to gaining an "extra" hour of sunlight at the end of the day during daylight saving time. "The consequence of that is that the majority of the population has drastically decreased productivity, decreased quality of life, increasing susceptibility to illness, and is just plain tired," Roenneberg said.

One reason so many people in the developed world are chronically overtired, he said, is that they suffer from "social jet lag.".