It means that the trait is heterozygous. Also, "T" is common used as the letter to represent the trait "Tall".
The circulatory system helps the excretory and digestive system do their jobs because the waste from the blood in the circulatory system is eliminated from the body through the excretory system, and the nutrients absorbed by the digestive system are transported through the blood.
Answer: <u>Capillaries
</u>
Explanation: There are two kinds of vessels which carry the blood throughout the body. These are veins and arteries. Now apart from these two, there is a third type which is called as capillaries, which are the connecting vessels between arteries and veins. These are relatively thinner and allow exchange of gases between tissues and the blood. Therefore, arteries and veins are incorrect options.
Heart is the pumping organ, and its function is to pump the blood to every cell of the body, so this can't be correct option.