What is the most common cause of a lowered immune system?

Apaleontologist finds a plant fossil that shows that the plant had seeds. what can the paleontologist conclude?

Which of the following typically characterizes a tropical rainforests

Below are the three main organs that make up the plant body. what is the main function of the structure that is identified as b in the picture above? it anchors the plant.it produces food.it absorbs nutrients.it supports the plan