Answer:
Brown is the dominant gene and white is the recessive gene.
Explanation:
If brown were to be dominant then the mice would most likely all be brown unless the got both a white from mom and dad which is most likely due to brown being recessive the dad could be part white you just wouldn't see it. And since the mother is white all of the mice get a white gene from the mom and since the dad most likely has a white gene hidden inside of him only tow mice became fully white while the siblings were brown.
Hope this helps.
The answer would be the last one because a deletion changes every codon configuration that follows it and thus changes the amino acid that codes for that codon
Answer: Four pulmonary veins.
Explanation: Oxygen and nutrient rich blood will flow from the lungs back into this part called the left atrium (Or as some will call it, the left upper chamber in the heart). From there, it goes through four pulmonary veins.
Hope I could help! :)