Question

The transverse section of a plant shows the following anatomical features- large numbers of scattered vascular bundles surrounded by bundle sheaths, large conspicuous parenchymatous ground tissue, vascular bundles are conjoint and closed, and phloem parenchyma absent. Identify the plant and its part.

• A. Dicotyledonous stem
• B. Dicotyledonous root
• C. Monocotyledonous stem
• D. Monocotyledonous root

Answer 1

The correct option is C

Monocotyledonous stem

The correct option is option C.

The explanation of the correct option:

1. Monocot stems have a circular form, lateral branches, and a layer of dermis enclosing them.
2. They have vascular bundles that are scattered throughout and they gradually begin to produce new vascular bundles as they get older. The structure of the bundles is closed and conjoint.
3. Phloem parenchyma is absent here because the vascular bundles lack cambium and are open, no secondary growth occurs.
4. Bundle sheath and observable parenchymatous tissues protect the tissue layers and plant nutrients are transported by the thick parenchymatous layers.
5. Examples of monocot stems include tulips, onions, lilies, and garlic.

The explanation of the incorrect option:

Option A:

1. Dicotyledonous plants are plants bearing seeds with two cotyledons.
2. A cambium layer, which is made up of meristematic cells, separates the xylem and phloem in the dicot stem. Due to the presence of cambium, the vascular bundles on the stem of a dicot are open.
3. Hence, it is an incorrect option.

Option B:

1. Dicotyledonous root contains the vascular bundles arranged in a ring. The dicot stem contains a variety of vascular bundle types, including conjoint, collateral, endarch, and open. It is composed of xylem, phloem, and cambium.
2. Hence, it is an incorrect option.

Option D:

1. The phloem parenchyma cells which are located between the sieve tubes of the phloem, serve the function to store food. Monocot roots, dicot roots, and dicot stem all include them. Monocot stems do not have them.
2. Hence, it is an incorrect option.

Final answer: Monocotyledonous stem possess large numbers of scattered vascular bundles surrounded by bundle sheaths, large conspicuous parenchymatous ground tissue, vascular bundles are conjoint and closed, and phloem parenchyma absent.