In rats, the allele for long whiskers is dominant to the allele for short whiskers. At another gene locus, a dominant allele produces whiskers and the recessive allele produces a rat with no whiskers. The alleles at these 2 gene loci assort independently. Two rats that are heterozygous at both gene loci are crossed. What percentage of the offspring do you expect will have whiskers? ( Enter the number only without the percent sign. For example, enter 100% as 100 and enter 12.5% as 12.5 )

1. emigration the movement of people from one place to another 2. immigration a situation in which resources are being used up at a faster rate than they can be replenished 3. migration the leaving of one's homeland to settle in a new place 4. overpopulation the movement of people to a new country 5. sustainable development a situation in which the birth rate is not sufficient to replace the existing population 6. underpopulation the ability to meet current needs without reducing the ability to meet future needs 7. unsustainable development the increase in the population of a city 8. urbanization a situation in which the number of people exceeds the available natural resources in an area