Answer:
1/4
Explanation:
Given that the disease cystic fibrosis is caused by a recessive allele (f), the individuals with genotype "ff" will express the disease. Both "FF and Ff" genotype will give the individuals a normal phenotype.
Both the parents are carrier (Ff) for the disease. They have 3/4 probability of getting a healthy child and 1/4 probability of getting a child with cystic fibrosis.
Astronomers use light years to measure distances in space because space is so massive and distances so far that conventional numbering is inadequate and unmanageable. One light year is a distance measurement equivalent to six trillion miles.
The correct answers are:
A. The southwest was covered with sand dunes. This period increased aridity in the southwest of the USA
.
D. Much of the northern United States was ice covered. During the last glacial period, the north of USA was covered by ice, in especial during the Last Glacial Maximum (LGM)
.
These answers are not correct:
B. Canada was covered with ice thousands of feet thick. During this period, Canada was almost completely covered in ice (97%); however, the ice was not so thick
.
C. Florida received heavy rains. Florida was drier during this period.