D, light can travel in the air or a vacuum and the speed is constant whether the light source is stationary or moving.
Answer:
Suffling of genetic material increases genetic variation in offspring which is important for evolution.
Explanation:
Genetic shuffling or genetic recombination helps in the formation of new trait combinations which increase the genetic variation in the population and this genetic variation is very much important for the evolution of species.
In sexual reproduction, the genetic shuffling occurs during the formation of gametes when the two homologous chromosomes exchange their genetic material with each other. This increase variation in gametes.
Fusion of two different gametes in sexual reproduction also helps in increasing the genetic variation in the offspring.
The culprit is an "arctic outbreak" that originated just above the US-Canada border, which is freezing temperatures across much of the US territory.
<h3>Arctic outbreak</h3>
"Bursts" of cold air like this are usually confined to the Arctic region thanks to a series of low-pressure systems, says the NWS. However, one of these waves advanced through Canada and "escaped" to the US.
According to experts heard by Reuters, it is a vast mass of icy air in the atmosphere, which brings with it frigid temperatures - which can be prolonged if storms form.
From this information we can conclude that according to the US Weather Service (NWS), the culprit is an "arctic outbreak" that originated just above the US-Canada border, which is freezing temperatures across much of the US territory.
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