This diagram represents a cross section of (circle one): monocot stem dicot stem monocot root dicot root leaf Label: epidermis ground tissue vascular bundles This diagram represents a cross- section of (ciroie one): monocot stem dicot stem monocot root dicot root leaf Label: epidermis corte pth endodermis pencycle xylem phioem
The Correct Answer and Explanation is :
To determine whether the diagram represents a monocot stem, dicot stem, monocot root, dicot root, or leaf, consider the following characteristics:
- Monocot Stem:
- Vascular bundles scattered throughout the ground tissue.
- No clear division between cortex and pith.
- Dicot Stem:
- Vascular bundles arranged in a ring.
- Clear separation of cortex (outer) and pith (inner).
- Monocot Root:
- A central core of parenchyma cells (pith) surrounded by a ring of vascular bundles.
- Endodermis and pericycle are prominent.
- Dicot Root:
- Vascular tissue forms a cross or star-shaped xylem in the center.
- Phloem surrounds the xylem arms, with an endodermis and pericycle encircling them.
- Leaf:
- Differentiation into upper and lower epidermis with mesophyll tissue (palisade and spongy layers) and vascular bundles forming veins.
Correct Answer:
Based on the labels provided, such as epidermis, cortex, pith, endodermis, pericycle, xylem, and phloem, the diagram represents a dicot root.
Explanation:
A dicot root cross-section can be identified by the following:
- The epidermis is the outermost protective layer.
- Beneath the epidermis is the cortex, composed of parenchyma cells that store nutrients.
- The endodermis surrounds the vascular cylinder, controlling water and solute movement.
- Inside the endodermis is the pericycle, a layer of cells that gives rise to lateral roots.
- The xylem (water-conducting tissue) forms a central star or cross shape.
- The phloem (food-conducting tissue) is located between the arms of the xylem.
The distinguishing feature of a dicot root is the star-shaped arrangement of xylem at the center, surrounded by phloem, endodermis, and pericycle. These traits contrast with monocot roots, where vascular bundles are arranged in a ring around a central pith.