An alleles is dominant is heterozygote when it is

An allele is dominant and heterzygote (Pp) when a dominant allele (P) is crossed with a recessive allele (p).

Explanation:

A dominant allele is the one with a particular dominant character or phenotype which dominates even though there are other alleles found.  

A heterozygous allele results from two different alleles coding for a gene.

A heterozygous dominant allele (Pp) results from the crossing of a dominant allele (P) with a recessive allele due to complete masking of the recessive allele (p).

For example, when dominant brown eyes are crossed with recessive blue eyes, in a heterozygous dominant allele results in brown eyes and masks the recessive blue eyes.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint

a. 35°c

b. 25°c

c. 10°c

d. 40°c