Anatomy of the Dicotyledonous Stem
A transverse section of a young dicotyledonous stem reveals a beautifully stratified organ. Reading it from the outside inward — epidermis, cortex, pericycle, vascular ring, pith — is the central skill this quiz develops.
In this quiz you will be tested on:
- The epidermis with its thin cuticle, trichomes and stomata
- The three-zoned cortex: collenchymatous hypodermis, parenchyma, and the starch sheath
- The semi-lunar sclerenchymatous pericycle and the medullary rays
- Vascular bundles arranged in a ring — conjoint, open, with endarch protoxylem
- The central pith of rounded parenchyma with large intercellular spaces
Each question is supported directly by the lesson material. Read each option carefully — the distractors are designed to test precise anatomical vocabulary.
Q1. In a transverse section of a typical young dicotyledonous stem, which layer forms the outermost protective boundary?
The lesson states that the epidermis is the outermost protective layer of the stem, covered with a thin layer of cuticle.
Q2. The epidermis of the young dicot stem is covered with a thin layer of which substance?
The epidermis is covered with a thin layer of cuticle, a waxy covering that limits uncontrolled water loss.
Q3. Which structures may the epidermis of the dicot stem bear, according to the lesson?
The lesson states that the epidermis, covered with a thin cuticle, may bear trichomes and a few stomata.
Q4. The hypodermis of the young dicot stem consists of a few layers of which type of cells?
The outer hypodermis consists of a few layers of collenchymatous cells just below the epidermis, which provide mechanical strength to the young stem.
Q5. What is the main function of the collenchymatous hypodermis in the young dicot stem?
The lesson states that the collenchymatous hypodermis provides mechanical strength to the young stem.
Q6. The cortical layers below the hypodermis consist of rounded, thin-walled parenchymatous cells with which feature?
The cortical layers below the hypodermis consist of rounded thin-walled parenchymatous cells with conspicuous intercellular spaces.
Q7. The innermost layer of the cortex of the dicot stem is called the endodermis, and it is also referred to as which of the following?
The cells of the endodermis are rich in starch grains, and the layer is therefore also referred to as the starch sheath.
Q8. In the dicot stem, the pericycle is present in the form of which structure?
The pericycle is present on the inner side of the endodermis and above the phloem in the form of semi-lunar patches of sclerenchyma.
Q9. The few layers of radially placed parenchymatous cells found between the vascular bundles of the dicot stem constitute which structure?
In between the vascular bundles there are a few layers of radially placed parenchymatous cells, which constitute the medullary rays.
Q10. Which arrangement of vascular bundles is stated to be a characteristic of the dicot stem?
A large number of vascular bundles are arranged in a ring, and this ring arrangement is a characteristic of the dicot stem.
Q11. Each vascular bundle of the dicot stem is described by which combination of terms?
The lesson states that each vascular bundle is conjoint, open, and with endarch protoxylem.
Q12. The central portion of the dicot stem is occupied by the pith, which consists of which type of cells?
The pith consists of a large number of rounded, parenchymatous cells with large intercellular spaces occupying the central portion of the stem.
Q13. Which sequence correctly reads the layers of a young dicot stem from the outside inward?
Reading the section from the outside inward gives epidermis, cortex, pericycle, vascular ring and pith.
Q14. The cortex of the dicot stem is described as consisting of three sub-zones. Which set correctly names them?
The cortex consists of three sub-zones: the outer hypodermis, the cortical parenchyma below it, and the innermost endodermis.
Q15. The pericycle of the dicot stem lies on the inner side of the endodermis and above which tissue?
The lesson states that the pericycle is present on the inner side of the endodermis and above the phloem in the form of semi-lunar patches of sclerenchyma.