Answer:
I think it will be C (viewpoint)
The mutation will occur on the X chromosome. Males are more susceptible to sickle cell amenia because they only carry one X chromosome instead of two when compared to a set of female chromosomes. If a female only has the mutation on one chromosome the disease will not appear. However, when a male recieves the mutation on the X chromosome, the disease would appear, because they only have one X chromosome.
1/4 recessive can be expected for the recessive trait of mono hybrids from the F2 generation.
Option D
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Explanation:</u></h3>
Mono hybrid cross is defined as the crossing between two plants considering the two different alleles of a particular character. It was 1st performed by Father of Genetics, Sir Gregor Mendel. The mono hybrid cross done by him considered the character tallness of garden pea plants, of which one was tall and other was short.
He crossed them to get all tall plants in 
Filial generation. Now as he self bred those plants, he got the tall and short plants in ratio of 3:1. Thus he proved that the recessive trait of mono hybrids is 
of the total population of F2 generation.
The correct answers is:
is formed when fuel is burned at high temperatures
<em>Nitrogen dioxide is another toxic gas that forms when fuels are burned at high temperatures.</em>
is the most abundant gas in the atmosphere
<em>The most abundant gas is nitrogen. Over 78 percent of the air we breathe is nitrogen (N)</em>
can cause acid rain
<em>Both nitrogen dioxide and sulfur dioxide can cause acid rain. The damage done by acid rain is devastating to the plants and animals in an ecosystem.</em>
is a major pollutant in the air
<em>AQI measures five major pollutants, including carbon monoxide, nitrogen dioxide (NO2), and sulfur dioxide (SO2).</em>
Wrong answers:
is a waste product of photosynthesis
<em>The waste product of photosynthesis is oxygen.</em>
