Why is it impossible for offspring to show recessive trait if one parent is homozygous for the dominant trait?

Imagine that a mouse has white fur because of a mutation in its dna. which of the following conclusions can be drawn

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.

Nh3 +02-no + h20 is unbalanced what is the balanced equation