What is the stalk that joins the leaf to the stem called? quizlit?

Petiole

Petiole is the stalk that joins the leaf to the stem.

The petiole is the supportive and transitional structure of the plant that joins the leaf to a stem. Petioles can be soft and porous, or thick. The petiole functions by conducting the energy that the leaves obtain using photosynthesis to every area of the plant. It also helps to move nutrients and water collected by the plant’s roots to other parts of the plant.

the answer is lactic acid from anaerobic respiration. the acid in lactic acid is what creates sore and burning muscles. if you think about how acid burns that will give you a clue for questions like this.

1. is geographic distribution

2 is increasing complexity

3 is transitional forms