Answer: Possession of Valves
Explanation: Veins possess valves which ensures that blood flows in only one direction. Valves helps blood to flow back to the heart against gravitational force.
Arteries don't have valves because the pressure originating from the heart is capable of causing the blood to flow in one direction.
Explanation:
A gene is the basic physical and functional unit of heredity. Genes are made up of DNA. Some genes act as instructions to make molecules called proteins.
Answer:
C
Explanation:
The genes contain codes that specify proteins, which produce traits.
