Nitrogen must be converted into nitrates before organisms can use it. If soil lacks nitrogen fixing bacteria, then it has few nitrates for the plants to take in.
Answer:
1/4
Explanation:
Cystic fibrosis is a recessive disorder and therefore, is expressed only in homozygous recessive genotype. Let's assume that the allele "c" is responsible for the disease in the homozygous state. Since the couple already has a child with cystic fibrosis (cc), they both are heterozygous carriers for the disease.
The genotype of male and female each is "Cc". A cross between Cc x Cc gives progeny in the following phenotype ratio=1/4 diseased: 1/2 normal carriers: 1/4 normal. Therefore, the probability of getting a diseased child for them is 1/4.
During the day the earth is heated by the sun. The earth heats the air and the air rises. As the hot air rises the cold air from the ocean takes its spot. In the night the opposite happens and the earth is cooled and the cool air rises so the warm air from the ocean takes the cold air's place. I hope this helps!