1.

B

2.

B

It is the leaf that is an appendage that is determinate in growth. The shoot apex also produces a stem (C) but that is not an appendage. The lateral shoot (A) which is the same as the axillary shoot (D) are appendages of the shoot apex, but they are indeterminate in growth.

3.

D

The way roots provide sufficient surface area, and one that can increase, by a system of cylinders that grow from their tips and branch by producing more cylinders that grow from their tips. The root system provides good anchorage (C) but that is not its main or primary purpose. The system does allow roots to go deeper (B) but this is not the driving force--plants produce roots in all directions and many need not go deeper for water, just further out in all directions.

4.

A

The principal role of cotyledons is nutrition, both the absorption of nutrients late in embryo and seed development and the provision of nutrients during germination. The seed coats (B) form from the integuments of the ovule; the root is protected by the root cap (C) and leaf primordia (D) form from the shoot apex in the embryo.

5.

B

Secondary growth, and in particular the vascular cambium, produces more conducting tissue, both xylem and phloem. The cork cambium adds cork cells to replace the epidermis, which has to the pushed off by the new tissue forming inside. Secondary growth does make the stem thicker and stronger (A) but that is not its first function. Leaves and flowers (C) come from the shoot apex--they are primary growth, not secondary. The stem tissue between leaves (D) comes from growth of that region and is primary growth.

6.

A

When you peel bark, you are breaking the tissue at its weakest point, where the vascular cambium is. (The cells are dividing and meristematic and very thin walled and easily broken.) Outside the vascular cambium includes all the phloem and all the periderm, or corky, layers. Since the phloem tissues carry the nutrients from the leaves to the roots, if you peel off a strip of bark around the entire diameter of a tree, the roots will starve and the tree will die. Deer often do this in the winter.

7.

A

By definition, wood is secondary xylem. Phloem is soft tissue and easy rots away when a tree is cut down; you would never build anything from phloem tissue.

8.

B

It is often called the transpiration-cohesion theory. The atmosphere is drier than the interior of the leaf and the evaporation of water from leaves causes the leaf cells to develop a more negative water potential and pull water from each other and eventually from the water-containing vessels and tracheids in the xylem tissue.

9.

C

Only the sieve cell is alive, functioning and without a nucleus. The guard cell (D) is alive and has a nucleus. The sieve cell (C) is dead when mature and lacks a nucleus and everything else except a cell wall. The cork cell (B) may or may not be dead when mature; if alive, it has its nucleus.

10.

D

The pressure flow theory states that solutes entering the sieve cell cause water to follow. Pressure builds up and both water and solute flow along the tube. There is "room" because cells at some other point, called the sink, are removing compounds/solutes. For the other choices: (A) guard cells contract and expand when they lose or gain water from adjacent cells but that water is never pumped anywhere else. (B) The cell surrounding the sieve cell-companion cell actively pump the solute into the them; the sieve cells do not pump. (C) Water does not evaporate at the sink. It enters the supply of water in the neighboring cells.

11.

A

In C-4 plants, the bundle sheath cells have the Calvin cycle where the radioactive carbon is incorporated into sugars. The carbon dioxide is first trapped in the mesophyll cells (B) by the Hatch and Slack cycle, but that generates only organic acids. It is these organic acids that travel to the bundle sheath and give up the carbon dioxide to the Calvin cycle. The sieve cells (C) receive the sugar after the Calvin cycle has manufactured it and the epidermal cells (D) never photosynthesize.