Answer:
DD or Dd
Explanation:
Dimples is the dominant trait (D). Your friend has dimples so that means he or she should have at least one allele of the dominant trait to express that trait. So your friend would either be homozygous dominant (DD) or heterozygous dominant (Dd). Notice that there is a recessive allele in the second. Even with that present, dimples would be still expressed.
A closed system is a system that makes no physical or chemical exchanges with its environment. Of these systems provided as choices (tree, human, clock, car), only a clock does not make exchanges with the environment, except for energy.
Therefore, of that list, only a clock would be a closed system.
Hope that helped! =)
All animals cannot make their own food, they are consumer
