Answer:
Greenhouse gases from human activities are the most significant driver of observed climate change since the mid-20th century.1 The indicators in this chapter characterize emissions of the major greenhouse gases resulting from human activities, the concentrations of these gases in the atmosphere, and how emissions and concentrations have changed over time. When comparing emissions of different gases, these indicators use a concept called “global warming potential” to convert amounts of other gases into carbon dioxide equivalents.
Explanation:
Why does it matter?
As greenhouse gas emissions from human activities increase, they build up in the atmosphere and warm the climate, leading to many other changes around the world—in the atmosphere, on land, and in the oceans. The indicators in other chapters of this report illustrate many of these changes, which have both positive and negative effects on people, society, and the environment—including plants and animals. Because many of the major greenhouse gases stay in the atmosphere for tens to hundreds of years after being released, their warming effects on the climate persist over a long time and can therefore affect both present and future generations.
In the block to polyspermy, entry of the sperm's contents causes calcium ion levels in the oocyte's cytoplasm to rise, triggering the cortical reaction.
In biology, polyspermy describes the fertilization of an egg by more than one sperm. Diploid organisms normally contain two copies of each chromosome, one from each parent.
The cell resulting from polyspermy, on the other hand, contains three or more copies of each chromosome—one from the egg and one each from multiple sperm. Usually, the result is an unviable zygote. This may occur because sperm are too efficient at reaching and fertilizing eggs due to the selective pressures of sperm competition.
The cortical reaction is a calcium-dependent exocytotic process in which the content of secretory granules is released into the perivitellin space immediately after fertilization, which serves to prevent polyspermic fertilization.
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Answer:
c) small plants grow but eventually replaced by larger plants.
At least one set of sister chromatids did not separate
compare the length of DNA among the member of a species. The modern taxonomy do the comparing of the length of DNA among the members of a species, that is to classify organisms.
