What is the part of a twig where a leaf once resided but is no longer there?

What is the primary function of roots?

What type of plant tissue is shown in the image below?

Looking at the growth rings in the image below of a stump, about how old is this tree?  

Where do paleobotanists think that plants evolved from?

Which tissue is responsible for food transport in plants?

This type of ground tissue has cells with FIBERS containing lignin, these cells are strong, common in pear tissue as well as coconut shells, known as stone cells or sclereids:

What is the lighter, outer portion of a tree trunk known as? (In the image, this is depicted by Part A, it is simply the lighter part of the wood on the outer rings).  

Which of the following is NOT a type of plant tissue?

  Which of the following issues led to the Cold War between the United States and the Soviet Union?