Anatomy of Plants MCQ Quiz - Objective Question with Answer for Anatomy of Plants - Download Free PDF

Key Points

• Nephridia are excretory organs found in annelids (e.g., earthworms) and not in prawns.
• Nephridia help in osmoregulation and excretion in annelids.
• Prawns use antennal glands (also known as green glands) for excretion.
• The green glands are responsible for eliminating nitrogenous waste in prawns.

Additional Information

• Coxal glands - Scorpions: Coxal glands are excretory organs found in arachnids such as scorpions. These glands help in the removal of nitrogenous wastes.
• Malpighian tubules - Insects: Malpighian tubules are a unique excretory system in insects. They are responsible for the removal of nitrogenous wastes and osmoregulation.
• Flame cells - Flatworms: Flame cells are specialized cells found in flatworms, such as planarians, for excretion and osmoregulation. They form part of the protonephridial system.
• Nephridia - Annelids: Nephridia are tubular excretory organs found in annelids like earthworms. They help in the removal of metabolic waste and maintenance of water balance.

The correct answer is Hypodermis is parenchymatous.

Explanation:

• The monocot stem has a sclerenchymatous hypodermis, a large number of scattered vascular bundles, each surrounded by a sclerenchymatous bundle sheath, and a large, conspicuous parenchymatous ground tissue
• Vascular bundles are conjoint and closed.
• Peripheral vascular bundles are generally smaller than the centrally located ones.
• The phloem parenchyma is absent, and water-containing cavities are present within the vascular bundles.

The correct answer is Monocot roots typically have more than six xylem bundles, while dicot roots have fewer xylem bundles.

Explanation:

• Both monocot and dicot roots have a small, underdeveloped pith: This statement is incorrect. While dicot roots often have a small and less prominent pith, monocot roots generally have a larger, more developed pith.
• Monocot roots typically have more than six xylem bundles, while dicot roots have fewer xylem bundles: This statement is correct. Monocot roots usually have a larger number of xylem bundles (often more than six), while dicot roots typically have fewer, commonly in the range of 2 to 6 xylem bundles.
• The cortex in monocot roots consists of sclerenchyma cells, while in dicot roots it consists of parenchyma cells: This statement is incorrect. In both monocot and dicot roots, the cortex typically consists of parenchyma cells. Sclerenchyma cells may be present in other parts of the plant but not predominantly in the cortex of roots.

The correct answer is Cortex cells contain chloroplasts for photosynthesis.

Concept:

• In Dicot root, the outermost layer is epiblema.
• Many of the cells of epiblema protrude in the form of unicellular root hairs.
• The cortex consists of several layers of thin-walled parenchyma cells with intercellular spaces.
• The innermost layer of the cortex is called endodermis.
• It comprises a single layer of barrel- shaped cells without any intercellular spaces.
• The tangential as well as radial walls of the endodermal cells have a deposition of water-impermeable, waxy material suberin in the form of casparian strips.
• Next to endodermis lies a few layers of thick-walled parenchyomatous cells referred to as pericycle.

Explanation:

• (A) It consists of thin-walled parenchyma cells: This statement is correct. The cortex in dicot roots is primarily made up of thin-walled parenchyma cells.
• (B) The cortex is several layers thick: This statement is correct. The cortex in dicot roots consists of multiple layers of parenchyma cells.
• (C) Cortex cells contain chloroplasts for photosynthesis: This statement is incorrect. The cortex in dicot roots does not contain chloroplasts because it is not involved in photosynthesis. Chloroplasts are typically found in the cells of the leaves and other green parts of the plant where photosynthesis occurs.
• (D) The cortex is located just inside the epiblema: This statement is correct. The cortex is located just inside the outermost layer, the epiblema (or epidermis), of the root.

Therefore, the incorrect statement regarding the cortex in dicot roots is: Cortex cells contain chloroplasts for photosynthesis.

The correct answer is The assertion is false, so is the reason.

Explanation:

• Assertion: The cortex of dicot roots is primarily composed of sclerenchyma cells. This statement is false. The cortex of dicot roots is primarily composed of parenchyma cells, which are involved in storage and the transport of nutrients and water.
• Reason: Sclerenchyma cells are involved in storage and lightweight transport of nutrients. This statement is also false. Sclerenchyma cells provide mechanical support due to their thick lignified walls and are not primarily involved in storage or transport of nutrients.

Therefore, both the assertion and the reason are false.

The correct answer is Ground tissue.

• The term cortex refers to the outermost layer of a structure.
• In the brain, the cortex most often refers to the cerebral cortex, although the cerebellum also has an outer layer called the cerebellar cortex.
• The three types of ground tissue: parenchyma, collenchyma, and sclerenchyma.
  • A function included photosynthesis, storage, regeneration, support, and protection.

Important Points

Additional Information

The correct answer is Epidermis.

Key Points

• Root hairs are slender projections originating from epidermal cells that function in nutrient and water uptake as well as in anchoring the root in the soil.
• In wild-type Arabidopsis, root hairs are formed by epidermal cells termed trichoblasts which overlie the boundary between two cortical cells

Additional Information

The correct answer is a type of epidermal tissue.

Key Points

• Stomatal guard cells are a type of epidermal tissue.
• The epidermal tissue system forms the outermost covering of the whole body plant.
• In the epidermal tissue system, the epidermis is the outermost layer of the main plant body.
• This layer is interrupted by stomata.
• The stomata are openings in the epidermis of most of the aerial parts of the plants, especially in the leaves.
• Each stomata is composed of two bean-shaped cells called guard cells, which enclose the stomatal pore.
• The stomatal guard cells are generally much smaller in size as compared to other epidermal cells.
• Stomatal guard cells help to regulate the rate of transpiration during photosynthesis by opening and closing the stomata. 

Concept:

1. Pith: 

It is the innermost part of tree consisting of cellular tissue which is used for nourishment of tree in young age.

2. Sapwood: 

It is the outer annual ring between heartwood and cambium layers. It is the living, outermost portion of a woody stem or branch.

3. Heartwood: 

The inner annual rings surrounding the pith are known as heartwood. It imparts rigidity to the tree.

4. Cambium Layer: 

It is a thin layer of sap between sapwood and the inner bark.

5. Inner bark: 

It gives protection to the cambium layer

6. Outer bark: 

It is the outermost part of the tree

7. Medullary sheath:

A thin radial fibres extending from pith to the cambium layer. 

The correct answer is xerophytes.

Key Points

• Xerophytes are plants found in the desert area.
• They require the least amount of water. In deserts there is a scarcity of water thus the plants have to take their water from the underground water level.
• Their stomata are of sunken type (deep-seated) like cup – shape depression as it helps them to prevent the loss of water through transpiration.
• Examples of xerophytes are – Aloe vera, Pineapple, Cactus, etc.

• The stomata are minute pores that occur in the epidermis of the plants.
• Each stoma remains surrounded by two kidneys or bean-shaped epidermal cells the guard cells.
•  The stomata may occur on any part of a plant except the roots.
• The epidermal cells bordering the guard cells are called accessory cells or subsidiary cells.
• The number and types of stomata vary in different plant species based on their Habitat.

Additional Information

• Hydrophytes are plants that are either partially or fully submerged into water.
• Partially submerged hydrophytes like Lilly have stomata present on their upper leaf surface (lower pat is submerged in water).
• Fully submerged hydrophytes like water ferns do not have stomata, instead of stomata, the plant's surface cells are capable of absorbing water, nutrients, and dissolved gases in the water.
• Mesophytes have generally stomata present on the lower surface of the epidermis
• Examples are corn(maize), clover, cucurbit, etc
• Parasite: The organism that lives on or inside other living organisms, to derive their food are called parasites. Amarbel (Cuscuta) is a ''parasite''.

Concept:

• Xylem and phloem are collectively termed vascular bundles. These may or may not have cambium.
• There are two types of vascular bundles:

      1.Conjoint vascular bundle - Xylem & phloem are present on the same radii.

• These can be further divided into three types (a) Collateral (b) Bicollateral & (c) Concentric

      2. Radial vascular bundle - Xylem & phloem are present on different radii in an alternate manner.

• Examples: Most of the roots (Dicot, a monocot, gymnosperm, fern-root)

Explanation:

• Conjoint Collateral vascular bundle: In this type of vascular bundle xylem and phloem are present on the same radius and phloem is present towards the periphery.
• These are of two types:

1. Open vascular bundle: If the cambium is present between the xylem and phloem, then it is said to be an open vascular bundle. Eg. Dicot stem.
2. Closed vascular bundle: When the cambium is absent between the xylem and phloem, then it is said to be a closed vascular bundle. Eg. Monocot stem

• The cambium present between the xylem and phloem in the open type of vascular bundle is responsible for the secondary growth like a woody stem in dicot plants.
• Thus, the correct option will be ''The presence of open vascular bundle is responsible for making the stem woody in dicot plants''.

Concept: 

• Interfascicular cambium is a continuous ring formed by the meristematic activity of the cells of medullary rays present next to intrafascicular cambium.
• Cork cambium is a meristematic tissue, which divides and replaces the broken cells of epidermal and cortex layer due to the high activity of vascular cambium.

​​​Explanation:

Option 1:

• Cell division is defined as the process where
• After mitosis, plant cells divide in half by forming a new cell wall (cell plate) between daughter nuclei.
• Both interfascicular cambium and cork cambium are not formed by cell division.
• Therefore, this is the incorrect option.

​Option 2:

• Cell differentiation is the process through which cells from the same source generate cell groups with different morphological and functional features over time.
• Interfascicular cambium and cork cambium is not formed by cell differentiation.
• Therefore, this is the incorrect option.

​Option 3:

• Cell dedifferentiation is defined as a temporary process in which cells become less specialized and return to an earlier cell state.
• Under some circumstances, a differentiated cell can regain its ability to divide.
• Cell dedifferentiation results in the formation of interfascicular cambium and cork cambium.
• Therefore, this is the correct answer.

​​Option 4:

• A mature plant cell loses its ability to divide after being dedifferentiated.
• Both the interfascicular cambium and cork cambium are not formed due to the process of redifferentiation.
• Therefore, this is the incorrect option.

​The correct answer is option 3.

Concept:

• Epidermis is the layer of cells present on the outside of plant structures such as stem, root, leaf, flower, fruit and seed.
• Epidermis comprises pavement cells, guard cells and subsidiary cells.
• Functions - 
  • Provides a barrier against water loss, infection and mechanical injury.
  • Helps regulate gas exchange.
  • Regulates transpiration.
  • Increases water absorption, etc.

Important Points

• Hair-like projections that extend from the epidermis are called trichomes.

Trichomes - 

• ​Trichomes are referred to as leaf hair.
• These can be singular or multicellular.
• The shape of trichomes helps in identifying a plant species.
• Trichomes are controlled by trichome specificity genes.
• The chemicals produced by trichomes in their glandular tips protect the plant from being eaten by insects.
• Apart from this, trichomes also produce secondary chemicals that are used as useful products such as fragrances and flavors.
• Some trichomes also contain irritants that can cause rashes in humans.
• In insectivorous plants like Drosera, trichomes secrete exudate that helps in trapping the prey.​

So the correct answer is option 4 (Trichomes).

Key Points

• Epithelial tissue or epithelium is a type of animal tissue that is found covering the outer surface of the body or organs. It is also present as a lining of the various ducts and tubes inside the body.
• It has a free surface that faces either a body fluid or an outside environment.
• The cells of the epithelial tissue lie on a thin layer of supportive tissue membrane called the basement membrane.
• There is no intercellular space between the compactly placed cells of the epithelial tissue.
• Epithelial tissue does not have blood vessels. Hence it is non-vascular.
• The main function of epithelial tissue is to protect other tissues.
• It may perform different functions depending on its location. E.g. Absorption in the digestive system, Secretion in gland cells, etc.
• Epithelial tissue has great regeneration power.
• There are two main types of epithelial tissue depending on the number of layers - Simple epithelium and Compound (Stratified) epithelium.

1. Simple epithelium:

• It is made up of a single layer of cells.
• It functions as a lining for the body cavity, ducts and tubes in the body.
• Simple epithelium is further divided into the following types: 
  1. Squamous epithelium
  2. ​Cuboidal epithelium
  3. Columnar epithelium
  4. ​Ciliated epithelium
  5. Glandular epithelium​​

2. ​​​Compound epithelium:
   • ​It is made up of more than one layer of cells.
   • The main function of compound epithelium is to protect other cells.

Explanation:

• a - always ciliated
  • This option is incorrect with regard to epithelial tissue.
  • Not all types of epithelial tissues bear cilia.
  • Ciliated epithelium is a type of epithelial tissue that bears cilia.
• b - non-vascular
  • This option is correct with regard to epithelial tissue.
  • Epithelial tissues do not have blood vessels.
  • Hence it can be regarded as non-vascular.
• c - with lots of extracellular material​
  • This option is incorrect with regard to epithelial tissue.
  • Epithelial tissues have scanty extracellular material.
  • The extracellular matrix consists of mainly the thin membrane - basement membrane. 
• d -  tightly packed​
  • This option is correct with regard to epithelial tissue.
  • The cells of the epithelial tissue are compactly packed with no intercellular space.

So the correct answer is option 2 - (b) + (d).

Key Points

• Casparian strips are located on the roots of the endodermis of vascular plants.
• It is a band of cell wall material deposited on the radial as well as tangential walls of the endodermis.
• The endodermis is the innermost layer of the cortex. It is made up of parenchymatous cells.

Explanation:

• Casparian strips are made of suberin.
• Suberin is a water-impermeable and waxy material.
• It is a lipophilic, hydrophobic polyester biopolymer.
• It blocks the passive flow of water and solutes into the stele of a plant.
• Suberin prevents water from entering the pericycle.
• Thus, Casparian strips help in producing root pressure.

Additional Information

• Chitin - is the N-acetylglucosamine polymer found in the cell wall of fungi and exoskeletons of Arthropods.
• Cellulose - is a polysaccharide and a structural component of the primary cell wall of plants.
• Pectin - is a heteropolysaccharide present in the primary cell wall and middle lamella of plants.

Hence, the correct option is (4) Suberin.