Tag: internal structure of stem(dicot and monocot)

Questions Related to internal structure of stem(dicot and monocot)

For a critical study of secondary growth in plants, which one of the following pairs is suitable?

botany internal structure of root, stem and leaf internal structure of dicot stem internal structure of stem(dicot and monocot) anatomy of stem

  1. Wheat and maiden hair fern

  2. Sugarcane and sunflower

  3. Teak and pine

  4. Deodar and fern

Show answer
Correct Option: C
Explanation:

Secondary growth occurs due to cell division in cambia or lateral meristems resulting in thickening of stems and roots. This is the characteristic feature of dicotyledons, gymnosperms and vascular system plants. Teak and pine belong to these systems and study of secondary growth is possible in these plants.

So, the correct answer is 'Teak and pine'

If the dicot stem is stained for starch, the most intense colouration would develop in

botany internal structure of root, stem and leaf internal structure of dicot stem internal structure of stem(dicot and monocot) anatomy of stem

  1. epiblema

  2. phloem

  3. endodermis

  4. pith

Show answer
Correct Option: C
Explanation:

Epiblema is the outer layer of the roots also known as epidermal cells of roots which perform the function of absorption.

Phloem is the conducting strands or tissues for the transport of food and minerals and is thus responsible for the nutrient supply of plants.
Endodermis is the layer in the center that surrounds the cortex of roots and stems. it is the layer which surrounds the vascular bundles. It is also called a starch sheath which has starch grains in the stems of dicots.
Pith is the central part of roots and stems which help in the nutrients supply.
So, the correct option is 'Endodermis'.

Select the correct option:

Given are a few peculiar parts/structures found in plants Cucurbita stem, potato tuber, walnut shell, jute fibres.
Identify the tissue responsible for the distinguishing feature in each part respectively and select the correct option

botany internal structure of root, stem and leaf internal structure of dicot stem internal structure of stem(dicot and monocot) anatomy of stem

  1. Collenchymatous hypodermis, Parenchyma, Sclerenchyma, Phloem

  2. Collenchymatous hypodermis, Sclerenchyma,Parenchyma, Phloem

  3. Parenchymatous hypodermis, Parenchyma, Sclerenchyma, Xylem

  4. Collenchymatous hypodermis, Parenchyma, Sclerenchyma, Xylem

Show answer
Correct Option: A
Explanation:
  1. Cucurbita stem: Collenchyma is the tissue of primary body. The cell walls show localized thickenings. It occurs chiefly in the hypodermis of dicot stems( e.g. Cucurbita, Helianthus).
    2. Potato tuber: Parenchyma is cell and tissue type in which the cells have only thin primary walls. The cotyledon of many leguminous plants contains protein and starch in their parenchyma cells. Protein and starch are present in the parenchyma of potato tuber.
    3. Walnut shell: Sclerenchyma consists of thick-walled dead cells. It usually occurs in hard parts of plant bodye.g. hard endocarp of Walnut, almond and coconut).
    4. Jute fibres: Phloem fibres are also called bast fibres and most occur in secondary phloem. The fibres of primary phloem have both cellulose and lignified thickenings.
    So, the correct answer is 'Collenchymatous hypodermis, Parenchyma, Sclerenchyma, Phloem'.

Read the following statements and select the correct option.


Statement 1: Annual rings are distinct in plants growing in temperate regions
Statement 2: In temperate regions, the climatic conditions are not uniform through the year

botany internal structure of root, stem and leaf internal structure of dicot stem internal structure of stem(dicot and monocot) anatomy of stem

  1. Both statements $1$ and $2$ are correct

  2. Statements $1$ is correct but statements $2$ is incorrect

  3. Statement $1$ is incorrect but statement $2$ is correct

  4. Both statements $1$ and $2$ are incorrect

Show answer
Correct Option: A
Explanation:

More distinct annual rings are formed in that regions, where climatic variations are sharp. More distinct annual rings are formed in temperate plants as the climatic conditions of temperate regions are not uniform.

Thus, both the statements are correct.
So, the correct option is (A).

Which of the following statements is incorrect?
botany internal structure of root, stem and leaf internal structure of dicot stem internal structure of stem(dicot and monocot) anatomy of stem

  1. In a dicot stem, the pericycle is usually multiplayered

  2. Wood is the common name used for secondary xylem

  3. Peripheral cytoplasm, a large vacuole and a prominent nucleus; all are absent in a mature sieve tube element

  4. Lenticels are the aerating pores present in bark of plants and are associated with gaseous exchange

Show answer
Correct Option: C
Explanation:

The cells of the seive tube elements contains protoplasm. a large vacuole however nucleus is lost at maturity. The conduction of food material takes between the cells through seive plants. The flow of food (sucrose), its loading etc is controlled by companion cells. Each seive tube cell is associated with one companion cell.

So, the correct answer is 'Peripheral cytoplasm, a large vacuole and a prominent nucleus; all are absent in a mature sieve tube element'

Hypodermis is _______ in sunflower stem and _________ in maize stem.

botany internal structure of root, stem and leaf internal structure of dicot stem internal structure of stem(dicot and monocot) anatomy of stem

  1. Parenchymatous, Collenchymatous

  2. Collenchymatous, Sclerenchymatous

  3. Sclerenchymatous, Collenchymatous

  4. Sclerechymatous, Parenchymatous

Show answer
Correct Option: B
Explanation:

Hypodermis is a distinctive layer of mechanical tissue present in some dicot and monocot stems. It is collenchymatous and present as 3-4 layers. It provides mechanical support and elasticity, also stores food.

In maize the hypodermis consists of a few layers of sclerenchymatous cells, interspersed by chlorenchyma cells. It provides mechanical support to the plant.
So, the correct answer is 'Collenchymatous, Sclerenchymatous'

The outermost portion of the cortex in stems of flowering plants is ______ and it is ______ in monocotyledonous stems.

botany internal structure of root, stem and leaf internal structure of dicot stem internal structure of stem(dicot and monocot) anatomy of stem

  1. (i) General cortex (ii) Parenchymatous

  2. (i) Endodermic (ii) Collenchymatous

  3. (i) General cortex (ii) Sclerenchymatous

  4. (i) Hypodermis (ii) Sclerenchymatous

Show answer
Correct Option: A
Explanation:

Cortex is the outermost layer of the stem or root of the plant. It is surrounded by a parenchymatous layer. The cortex is unspecialized cells which help as conducting tissue in the plants.

So,the correct option is '(i) General cortex (ii) Parenchymatous

In which structure peripheral vascular bundles are generally smaller than centrally located ones?

botany internal structure of root, stem and leaf internal structure of dicot stem internal structure of stem(dicot and monocot) anatomy of stem

  1. Dicot stem

  2. Monocot stem

  3. Dicot root

  4. Monocot root

Show answer
Correct Option: A,B
Explanation:

Peripheral vascular bundles are generally smaller than the centrally located ones because the phloem parenchyma is absent and the water containing cavities are present in the vascular bundles which are both in monocot and dicot stem.


So, the correct options are 'Monocot stem' and 'Dicot stem'.

Monocot roots differ from dicot roots in having 

botany internal structure of root, stem and leaf internal structure of dicot stem internal structure of stem(dicot and monocot) anatomy of stem

  1. Open vascular system

  2. Presence of root hair

  3. Number of xylem / phloem strands

  4. Presence of cortex

Show answer
Correct Option: C
Explanation:

Most of the features of the dicot and monocot roots are similar except the vascular bundles. In the dicot root, there are 2-6 bundles of xylem and phloem alternating whereas in monocots the number of xylem and phloem strands are more than 8. Further, the xylem vessels in dicots are polygonal and those of monocots are oval.

Therefore, the correct answer is option C.

In a dicot stem, pericycle gives rise to

botany internal structure of root, stem and leaf internal structure of dicot stem internal structure of stem(dicot and monocot) anatomy of stem

  1. Interfascicular cambium

  2. Phellogen

  3. Secondary cortex

  4. Secondary wood

Show answer
Correct Option: B
Explanation:
  • In dicot stem, the secondary vascular tissues originate as a result of the cambial activity. 
  • The cambial cells divide tangentially again and again and produce secondary tissues. 
  • Some of the cells of single-layered pericycle become meristematic, which divides and form a few layers of cells, phellogen.
  • Hence, In a dicot stem, pericycle gives rise to Phellogen.
  • So, the correct answer is 'Phellogen'.