7. Which structures open and close the stoma to allow gas exchange and reduce water loss in leaves? A. epidermis B. vascular tissue C. guard cells D. spongy mesophyll loots and Stems

## Step 1<br />The question is asking about the structures in leaves that open and close the stomata to allow gas exchange and reduce water loss. The stomata are small openings on the surface of leaves that allow gases to be exchanged between the plant and the atmosphere.<br /><br />## Step 2<br />The options provided are:<br />A. Epidermis<br />B. Vascular tissue<br />C. Guard cells<br />D. Spongy mesophyll<br /><br />## Step 3<br />The epidermis is the outermost layer of cells covering the plant. It does not control the opening and closing of the stomata.<br /><br />## Step 4<br />Vascular tissue is responsible for the transport of water, nutrients, and sugars throughout the plant. It does not control the opening and closing of the stomata.<br /><br />## Step 5<br />Guard cells are specialized cells in the epidermis of leaves, stems, and other organs that are used to control the opening and closing of the stomata. They do this by changing shape in response to environmental conditions.<br /><br />## Step 6<br />Spongy mesophyll is a type of tissue in the interior of leaves where gas exchange occurs. It does not control the opening and closing of the stomata.