Which type of heat transfer has warm fluids rising and cold fluids sinking?(science)

1. watermelon, papaya, oranges, bananas, and lemons are included in this food group. vitamin c 2. you need 6 or more servings of this food group each day vitamins d and a 3. found in fruit and keeps blood vessels healthy calcium 4. vitamins found in milk bread and grain 5. a mineral that strengthens bones fruit

What is the problem in this article? what solution does the article propose?

As the pea seeds respire, the level of coloured liquid in the left hand part of the capillary tube rises. by referring to what is happening in the apparatus, explain why the level of liquid changes