Answer:
c. mid-adulthood
Explanation:
This stage of life when gray hairs become overwhelming in number and he has more gray hairs than brunette( brown hair) is called middle adulthood. Middle adulthood spans from 20 to 40 years of life which may be defined differently for different culture and country.
Robert is in his late mid adulthood somewhere near 40 at this age hair generally grow grey.
Answer: DNA
Explanation:
DNA also referred to as deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Almost every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus.
Answer:
According to the pyramid of energy, the energy content is maximum in autotrophs or producers. Autotrophs are the plants which prepare their food by photosynthesis. They are the primary producers and primary source of food energy. The flow of energy is unidirectional from producer to consumer level.
Explanation:
Smoking is a huge factor that drives this disease, specifically tobacco.
the answer is c. hydrogen bonding