B. meiosis. This process randomly rearranges the pairs of homologous chromosomes in formation of the sex cells. In addition, there is crossing-over of the chromatids while the homologous chromosomes are synapsed during meiosis I.
B. skeletal and nervous system
<span>Acute exposure to radioactive substances.
Acute exposure is radiation exposure that occurs in a short time period. It can be an exposure that occurs once in your lifetime. This might be that one foot x ray you had because you may have broken your foot. Acute exposure can also be exposures that occur more than once, but very infrequently and for short periods of time. This might be dental x rays you get every few years.</span>
More than 150 years ago, inventors began working on a bright idea that would have a dramatic impact on how we use energy in our homes and offices. This invention changed the way we design buildings, increased the length of the average workday and jumpstarted new businesses. It also led to new energy breakthroughs -- from power plants and electric transmission lines to home appliances and electric motors.
Like all great inventions, the light bulb can’t be credited to one inventor. It was a series of small improvements on the ideas of previous inventors that have led to the light bulbs we use in our homes today.