MORPHOLOGY OF FLOWERING PLANTS MCQs for NEET UG BIOLOGY — Hard, Page 3

61 Hard

Understanding +4 | -1

In which of the following, parthenocarpy makes no sense?

View answer and explanation

Correct option: D

Pomegranate

Option D (Pomegranate) is correct because parthenocarpy, the development of fruit without fertilization, is not advantageous in pomegranates as the edible part consists of seeds, which are absent in parthenocarpic fruits.

Solution approach

Correct Answer + Core Reason: Pomegranate. Parthenocarpy is not useful in pomegranate because the edible part is the seed.

Step-by-Step Solution:

Step 1: Define parthenocarpy: Development of fruit without fertilization.

Step 2: Consider the edible part of each fruit:
- Banana: Fleshy pericarp (developed without seeds)
- Orange: Juicy segments (developed around seeds, but parthenocarpy still results in edible fruit)
- Lemon: Juicy segments (similar to orange)
- Pomegranate: Arils (fleshy seed coverings)

Step 3: Evaluate the impact of parthenocarpy on each fruit. Parthenocarpy in banana, orange, and lemon still results in an edible fruit, even without seeds. However, in pomegranate, the edible part *is* the seed. Without fertilization, there are no seeds, and thus no edible part.

Step 4: Conclude that parthenocarpy makes no sense in pomegranate.

Why other options are wrong:
- Option A (Banana): Parthenocarpy is common and desirable in bananas, as it results in seedless fruits.
- Option B (Orange): Parthenocarpy can occur in oranges, resulting in seedless varieties, which are still edible.
- Option C (Lemon): Similar to oranges, parthenocarpy in lemons can produce seedless fruits that are still edible.

Key Concepts:
- Parthenocarpy
- Fruit development
- Edible parts of fruits

Memory Aids:
- Parthenocarpy = No seeds

Quick Tips:
- Consider the edible part of the fruit and whether it depends on seed development.

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False Fruits are found in

View answer and explanation

Correct option: D

All

Option D (All) is correct because apple, strawberry, and cashew nut are all examples of false fruits.

Solution approach

Correct Answer + Core Reason: All. Apple, strawberry, and cashew nut are all false fruits.

Step-by-Step Solution:
Step 1: The question asks to identify the plants that produce false fruits.
Step 2: Recall the definition of a false fruit: A fruit in which some of the fleshy part is derived not from the ovary but from some other part of the flower.
Step 3: Apple, strawberry, and cashew nut are all examples of false fruits.

Why other options are wrong:
- Option A: Apple is a false fruit, but the question asks for all examples.
- Option B: Strawberry is a false fruit, but the question asks for all examples.
- Option C: Cashew Nut is a false fruit, but the question asks for all examples.

Key Concepts:
- True vs. False Fruits

Memory Aids:
- Remember that in false fruits, parts other than the ovary contribute to the fruit structure.

Quick Tips:
- Understand the difference between true and false fruits.

63 Hard

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Assertion : Roots contain nodes but no leaves or buds.

Reason : Root branches arise endogenously.

View answer and explanation

Correct option: D

If the assertion is false but reason is true

Option D (If the assertion is false but reason is true) is correct. Roots do not contain nodes, but root branches arise endogenously.

Solution approach

Correct Answer + Core Reason: If the assertion is false but reason is true. Roots do not have nodes, and root branches originate from the pericycle (endogenously).

Step-by-Step Solution:

Step 1: Analyze the Assertion: Roots contain nodes but no leaves or buds. This is incorrect; roots do not have nodes.

Step 2: Analyze the Reason: Root branches arise endogenously. This is true; root branches originate from the pericycle, which is an internal tissue.

Step 3: Determine if the assertion and reason are true and if the reason explains the assertion.

Why other options are wrong:
- Option A (If both the assertion and the reason are true and the reason is a correct explanation of the assertion): The assertion is false.
- Option B (If both the assertion and reason are true but the reason is not a correct explanation of the assertion): The assertion is false.
- Option C (If the assertion is true but the reason is false): The assertion is false and the reason is true.

Key Concepts:
- Root anatomy
- Root branching
- Endogenous origin
- Plant morphology

Memory Aids:
- Roots = No nodes
- Endogenous = Inside (origin of root branches)

Quick Tips:
- Remember the key features of root structure and branching.

64 Hard

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Scaly bulb stem modification is seen in

View answer and explanation

Correct option: B

Lilium

Option B (Lilium) is correct because Lilium (lily) exhibits a scaly bulb stem modification, where the bulb consists of overlapping scales.

Solution approach

Correct Answer + Core Reason: Lilium. Lilium exhibits a scaly bulb stem modification.

Step-by-Step Solution:

Step 1: Define bulb stem modification.

Step 2: Identify different types of bulbs.

Step 3: Scaly bulbs consist of overlapping scales without a tunic.

Step 4: Lilium (lily) is a classic example of a scaly bulb.

Why other options are wrong:
- Option A: Allium (onion, garlic) has a tunicated bulb, not a scaly bulb.
- Option C: Scilla also has a tunicated bulb.
- Option D: Ginger is a rhizome, a horizontal underground stem, not a bulb.

Key Concepts:
- Stem modifications
- Bulbs (tunicated vs. scaly)
- Rhizomes

Memory Aids:
- Lilium = Lily = Scaly bulb.

Quick Tips:
- Understand the different types of stem modifications and their examples.

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What type of placentation is seen in sweet pea?

View answer and explanation

Correct option: D

Marginal

Option D (Marginal) is correct because sweet pea exhibits marginal placentation, where the placenta forms a ridge along the ventral suture of the ovary.

Solution approach

Correct Answer + Core Reason: Marginal. Sweet pea exhibits marginal placentation.

Step-by-Step Solution:

Step 1: Define placentation. Placentation refers to the arrangement of ovules within the ovary.

Step 2: Describe Marginal placentation. In marginal placentation, the placenta forms a ridge along the ventral suture of the ovary, and the ovules are borne on this ridge. This type of placentation is characteristic of legumes like sweet pea.

Step 3: Describe Basal placentation. In basal placentation, the placenta develops at the base of the ovary, and a single ovule is attached to it. Example: sunflower, marigold.

Step 4: Describe Axile placentation. In axile placentation, the placenta is axial, and the ovules are attached to it in a multilocular ovary. Example: tomato, lemon, china rose.

Step 5: Describe Free central placentation. In free central placentation, the ovules are borne on a central axis without any septa. Example: Dianthus, Primrose.

Step 6: Conclusion. Sweet pea belongs to the family Fabaceae (legumes), which is characterized by marginal placentation.

Why other options are wrong:
- Option A: Basal placentation is found in plants like sunflower and marigold, not sweet pea.
- Option B: Axile placentation is found in plants like tomato and lemon, not sweet pea.
- Option C: Free central placentation is found in plants like Dianthus and Primrose, not sweet pea.

Key Concepts:
- Placentation types: Marginal, Basal, Axile, Free central

Memory Aids:
- Marginal: Think of peas arranged along the margin of the pod.
- Basal: Think of a base with a single ovule.
- Axile: Think of an axis in the center with multiple compartments.
- Free central: Think of a free-standing central column.

Quick Tips:
- Memorize the definitions and examples of each type of placentation.

66 Hard

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How many of the following organisms show the type of symmetry which is similar
to actinomorphic flowers?
Spongilla, Adamsia, Gorgonia, Pleuroblanchia, Taenia, Cucumaria, Ophiura

View answer and explanation

Correct option: C

5

The correct answer is C (5) because Spongilla, Taenia, and Pleurobranchia exhibit asymmetry or bilateral symmetry, while Adamsia, Gorgonia, Cucumaria and Ophiura show radial symmetry similar to actinomorphic flowers.

Solution approach

Correct Answer + Core Reason: 5. Adamsia, Gorgonia, Cucumaria and Ophiura exhibit radial symmetry, similar to actinomorphic flowers.

Step-by-Step Solution:

Step 1: Define Actinomorphic: Actinomorphic flowers exhibit radial symmetry (can be divided into equal halves by multiple planes).

Step 2: Analyze each organism:
- Spongilla: Asymmetrical
- Adamsia: Radial symmetry
- Gorgonia: Radial symmetry
- Pleurobrachia: Radial symmetry
- Taenia: Bilateral symmetry
- Cucumaria: Radial symmetry
- Ophiura: Radial symmetry

Step 3: Count the organisms with radial symmetry: Adamsia, Gorgonia, Pleurobrachia, Cucumaria, Ophiura. That's 5 organisms.

Why other options are wrong:
- Option A: 7 - Incorrect; not all organisms listed have radial symmetry.
- Option B: 6 - Incorrect; only 5 organisms have radial symmetry.
- Option D: 4 - Incorrect; 5 organisms have radial symmetry.

Key Concepts:
- Symmetry in organisms (radial, bilateral, asymmetry)
- Actinomorphic flowers

Memory Aids:
- Radial symmetry = multiple planes of symmetry
- Bilateral symmetry = one plane of symmetry

Quick Tips:
- Know the different types of symmetry and examples of organisms exhibiting each type.

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Which of the statements supports that a flower is a highly condensed and modified part of the plant body?

View answer and explanation

Correct option: C

The flower may develop in the axis of a small leaf - like structure called bract.

The correct answer is C (The flower may develop in the axis of a small leaf - like structure called bract.) because the presence of a bract supports the idea that a flower is a modified shoot.

Solution approach

Correct Answer + Core Reason: The flower may develop in the axis of a small leaf - like structure called bract. This supports the flower being a modified shoot.

Step-by-Step Solution:

Step 1: Understand the concept: A flower is considered a modified shoot because its parts are homologous to leaves and stems.

Step 2: Evaluate option A: Anatomically, the pedicel and thalamus of a flower resembles that of a flower - This is vague and doesn't directly support the modified shoot theory.

Step 3: Evaluate option B: Except for the lower internode, other internodes are condensed forming a broad bas called thalamus - This describes the thalamus but doesn't strongly support the modified shoot theory.

Step 4: Evaluate option C: The flower may develop in the axis of a small leaf - like structure called bract - This is analogous to a leaf arising from a stem, supporting the flower as a modified shoot.

Step 5: Conclusion: Option C provides the strongest evidence for the flower being a modified shoot.

Why other options are wrong:
- Option A: Anatomically, the pedicel and thalamus of a flower resembles that of a flower - This is a self-referential and weak argument.
- Option B: Except for the lower internode, other internodes are condensed forming a broad bas called thalamus - This describes the thalamus but doesn't strongly support the modified shoot theory.
- Option D: All of the above - Incorrect because options A and B are weak arguments.

Key Concepts:
- Flower as a modified shoot
- Bracts
- Plant Morphology

Memory Aids:
- Bract = Leaf-like structure at the base of a flower

Quick Tips:
- Look for direct evidence supporting the flower as a modified shoot.

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Pedicel of flower is called

View answer and explanation

Correct option: D

Either (a) or (b)

Correct Answer + Core Reason: Either (a) or (b). Both Thalamus and Receptacle can refer to the pedicel of the flower.

Step-by-Step Solution:

Step 1: Define the terms:
- Pedicel: The stalk of a flower.
- Thalamus: The expanded end of the pedicel where floral organs are attached; also called the receptacle.
- Receptacle: The expanded end of the pedicel where floral organs are attached; also called the thalamus.

Step 2: Analyze the options:
- Thalamus and receptacle are essentially the same structure.

Step 3: Therefore, the pedicel of a flower can be referred to as either the thalamus or the receptacle.

Why other options are wrong:
- Option A: Thalamus alone is not entirely correct as receptacle is also used.
- Option B: Receptacle alone is not entirely correct as thalamus is also used.
- Option C: Both (a) and (b) is not entirely correct because the question asks what the pedicel is called, not the structure that holds the floral parts.

Key Concepts:
- Flower morphology
- Thalamus/Receptacle
- Pedicel

Memory Aids:
- Thalamus and receptacle are interchangeable terms.

Quick Tips:
- Understand the basic structure of a flower and the terms associated with it.

Solution approach

Correct Answer + Core Reason: Either (a) or (b). Thalamus and receptacle are the same structure and refer to the expanded end of the pedicel.

Step-by-Step Solution:

Step 1: Define the terms:
- Pedicel: The stalk of a flower.
- Thalamus: The expanded end of the pedicel where the floral organs are attached. Also known as the receptacle.
- Receptacle: Same as thalamus.

Step 2: The question asks what the pedicel is called. The thalamus and receptacle are parts *of* the pedicel, specifically the expanded end.

Step 3: The question is poorly worded. It seems to be implying that the thalamus/receptacle *is* the pedicel, which isn't technically correct. However, since the thalamus and receptacle are the same thing, either answer is acceptable in the context of the question.

Why other options are wrong:
- Option A: Thalamus is a part of the pedicel, but not the entire pedicel itself.
- Option B: Receptacle is a part of the pedicel, but not the entire pedicel itself.
- Option C: Both (a) and (b) is technically incorrect because the pedicel is the stalk, and the thalamus/receptacle is the expanded end of the stalk.

Key Concepts:
- Flower morphology
- Pedicel, Thalamus, Receptacle

Memory Aids:
- Thalamus = Receptacle

Quick Tips:
- Pay attention to the precise definitions of floral terms.

69 Hard

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Assertion (A): Parthenocarpy is undesirable in nut crops, such as pistachio.

Reason (R): The seed is the edible part in nut crops.

View answer and explanation

Correct option: A

Both (A) & (R) are true and the (R) is the correct explanation of the (A)

Option A is correct because parthenocarpy (fruit development without fertilization) is undesirable in nut crops where the seed is the edible part.

Solution approach

Correct Answer + Core Reason: Both (A) & (R) are true and the (R) is the correct explanation of the (A). Parthenocarpy results in seedless fruits, which is undesirable when the seed is the edible part.

Step-by-Step Solution:

Step 1: Define parthenocarpy: Parthenocarpy is the development of fruit without fertilization.

Step 2: Consider nut crops: In nut crops like pistachio, the seed is the primary edible part.

Step 3: Analyze the assertion: If parthenocarpy occurs, the nut will be seedless, making it undesirable.

Step 4: Analyze the reason: The reason correctly states that the seed is the edible part in nut crops.

Step 5: Determine if the reason explains the assertion: The reason explains why parthenocarpy is undesirable because it eliminates the edible part (the seed).

Why other options are wrong:
- Option B: While both statements are true, the reason *is* the correct explanation.
- Option C: Both assertion and reason are true.
- Option D: Both assertion and reason are true.

Key Concepts:
- Parthenocarpy
- Nut crops
- Seed development

Memory Aids:
- Parthenocarpy = "virgin fruit" (development without fertilization)

Quick Tips:
- Understand the economic importance of different plant parts to determine the desirability of certain reproductive processes.

70 Hard

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Assertion (A): In Calotropis and guava opposite phyllotaxy is found.

Reason (R): In Calotropis a pair of leaves arise on each node.

View answer and explanation

Correct option: A

Both (A) & (R) are true and the (R) is the correct explanation of the (A)

Option A is correct because both the assertion (opposite phyllotaxy in Calotropis and guava) and the reason (pair of leaves at each node) are true, and the reason correctly explains the assertion.

Solution approach

Correct Answer + Core Reason: Both (A) & (R) are true and the (R) is the correct explanation of the (A). Calotropis and guava have opposite phyllotaxy because a pair of leaves arise on each node.

Step-by-Step Solution:

Step 1: Define opposite phyllotaxy.

Step 2: Recall examples of plants with opposite phyllotaxy.

Step 3: Determine if Calotropis and guava have opposite phyllotaxy.

Step 4: Determine if the reason correctly explains the assertion.

Why other options are wrong:
- Option A: Both assertion and reason are true, and the reason correctly explains the assertion.
- Option B: The reason correctly explains the assertion.
- Option C: The assertion is true.
- Option D: Both assertion and reason are true.

Key Concepts:
- Phyllotaxy types: opposite

Memory Aids:
- Opposite = Pair of Leaves

Quick Tips:
- Remember examples of plants with opposite phyllotaxy.

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Natural systems of classification take into consideration?

View answer and explanation

Correct option: D

All of these

Option D (All of these) is correct because natural systems of classification consider morphological, anatomical, cytological, embryological, physiological, and reproductive characters.

Solution approach

Correct Answer + Core Reason: All of these. Natural systems consider all given characteristics.

Step-by-Step Solution:

Step 1: Understand the question. The question asks about the characteristics considered in natural systems of classification.

Step 2: Recall the definition of natural classification. Natural classification systems are based on overall similarities and evolutionary relationships, considering various characteristics.

Step 3: Evaluate the options. Morphological, anatomical, cytological, embryological, physiological, and reproductive characters are all important in determining natural relationships.

Step 4: Conclude that all options are considered.

Why other options are wrong:
- Option A: Morphological and anatomical characters are important, but not the only ones considered.
- Option B: Cytological and embryological characters are important, but not the only ones considered.
- Option C: Physiological and reproductive characters are important, but not the only ones considered.
- Option D: This option encompasses all the relevant characters considered in natural classification.

Key Concepts:
- Natural systems of classification
- Morphological characters
- Anatomical characters
- Cytological characters
- Embryological characters
- Physiological characters
- Reproductive characters

Memory Aids:
- Think of \"holistic\" approach for natural classification.

Quick Tips:
- When a question asks about \"all,\" make sure each individual component is correct.

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The binomial of sunnhemp is

View answer and explanation

Correct option: A

Crotalaria juncea

Option A (Crotalaria juncea) is correct because Crotalaria juncea is the binomial name for sunnhemp, a fiber crop.

Solution approach

Correct Answer + Core Reason: Crotalaria juncea. This is the binomial name for sunnhemp.

Step-by-Step Solution:

Step 1: Recall the binomial nomenclature system.

Step 2: Consider the given options and their common names.

Step 3: Crotalaria juncea is the scientific name for sunnhemp.

Why other options are wrong:
- Option B: Erythrina indica is the Indian coral tree.
- Option C: Glycine max is soybean.
- Option D: Arachis hypogaea is groundnut.

Key Concepts:
- Binomial nomenclature
- Scientific names of plants

Memory Aids:
- Crotalaria juncea = Sunnhemp.

Quick Tips:
- Memorize the scientific names of important plants.

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Haustoria produced by striga are connected to?

View answer and explanation

Correct option: B

Only xylem of the host

The correct answer is B (Only xylem of the host) because Striga's haustoria primarily connect to the host plant's xylem to extract water and nutrients.

Solution approach

Correct Answer + Core Reason: Only xylem of the host. Striga connects to the xylem for water and nutrients.

Step-by-Step Solution:

Step 1: Understand the parasitic nature of Striga.

Step 2: Recall the function of haustoria in parasitic plants.

Step 3: Identify that Striga's haustoria connect to the xylem of the host plant to obtain water and nutrients.

Step 4: Conclude that the correct answer is only xylem of the host.

Why other options are wrong:
- Option A: Striga primarily connects to the xylem, not the phloem, for water and nutrient uptake.
- Option C: Striga connects primarily to the xylem, not both xylem and phloem.
- Option D: Striga connects to the xylem, so it does connect to the host's vascular system.

Key Concepts:
- Parasitic plants
- Haustoria
- Xylem
- Phloem

Memory Aids:
- Striga = Xylem parasite

Quick Tips:
- Remember that parasitic plants use haustoria to connect to the vascular system of their host.

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Pneumatophores are positively

View answer and explanation

Correct option: D

Both 2 and 3

Option D (Both 2 and 3) is correct because pneumatophores are negatively geotropic (grow against gravity) and positively phototropic (grow towards light) and aerotropic (grow towards air).

Solution approach

Correct Answer + Core Reason: Both 2 and 3. Pneumatophores are positively phototropic and aerotropic.

Step-by-Step Solution:

Step 1: Define pneumatophores. Pneumatophores are specialized root structures that grow upwards out of the water or mud to obtain oxygen from the air.

Step 2: Consider the tropisms:
- Geotropic: Growth in response to gravity.
- Phototropic: Growth in response to light.
- Aerotropic: Growth in response to air.

Step 3: Determine the tropisms of pneumatophores. Pneumatophores are negatively geotropic (grow against gravity) and positively phototropic and aerotropic (grow towards light and air).

Step 4: Conclusion: Pneumatophores are positively phototropic and aerotropic.

Why other options are wrong:
- Option A: Geotropic. Pneumatophores are negatively geotropic, not positively geotropic.
- Option B: Phototropic. While pneumatophores are phototropic, this is not the complete answer.
- Option C: Aerotropic. While pneumatophores are aerotropic, this is not the complete answer.

Key Concepts:
- Pneumatophores
- Tropisms
- Plant adaptations

Memory Aids:
- Pneumatophores = Air roots = Positive phototropism and aerotropism

Quick Tips:
- Remember that pneumatophores grow upwards to obtain air.

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[A]: In creepers, leaves are produced upon the nodes.

[R]: Adventitious roots arise from the nodes.

View answer and explanation

Correct option: B

Both A and R are true and R is not the correct explanation of A

Option B is correct because in creepers, leaves are produced upon the nodes, and adventitious roots arise from the nodes, but the reason is not the correct explanation of the assertion.

Solution approach

Correct Answer + Core Reason: Both A and R are true and R is not the correct explanation of A. Creepers produce leaves at nodes, and adventitious roots arise from nodes, but one doesn't explain the other.

Step-by-Step Solution:

Step 1: Analyze Assertion [A]: In creepers, leaves are produced upon the nodes.

Step 2: Evaluate Assertion [A]: This is true; creepers produce leaves at nodes.

Step 3: Analyze Reason [R]: Adventitious roots arise from the nodes.

Step 4: Evaluate Reason [R]: This is also true; adventitious roots arise from the nodes in creepers.

Step 5: Determine if R explains A: The presence of adventitious roots at the nodes doesn't explain why leaves are also produced at the nodes.

Step 6: Conclusion: Both A and R are true, but R is not the correct explanation of A.

Why other options are wrong:
- Option A: Both A and R are true and R is the correct explanation of A: R does not explain A.
- Option C: A is true but R is false: R is also true.
- Option D: Both A and R are false: Both A and R are true.

Key Concepts:
- Plant morphology
- Creepers
- Nodes
- Adventitious roots

Memory Aids:
- Remember that nodes are points of leaf and root development in creepers.

Quick Tips:
- Determine if the reason directly explains the assertion.

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The leaves of Smilax and Colocasia show

View answer and explanation

Correct option: B

Reticulate venation

Option B (Reticulate venation) is correct because both Smilax and Colocasia, being dicotyledonous plants, typically exhibit reticulate venation in their leaves.

Solution approach

Correct Answer + Core Reason: Reticulate venation. Smilax and Colocasia show reticulate venation.

Step-by-Step Solution:

Step 1: Define venation. Venation refers to the arrangement of veins and veinlets in the lamina of a leaf.

Step 2: Describe Reticulate venation. In reticulate venation, the veins are arranged in a network or web-like pattern. This type of venation is typically found in dicotyledonous plants.

Step 3: Describe Parallel venation. In parallel venation, the veins run parallel to each other from the base to the apex of the leaf. This type of venation is typically found in monocotyledonous plants.

Step 4: Identify Smilax and Colocasia. Smilax is an exception to the monocot rule and exhibits reticulate venation. Colocasia is a dicot and exhibits reticulate venation.

Step 5: Conclusion. Since both Smilax and Colocasia exhibit reticulate venation, the correct answer is reticulate venation.

Why other options are wrong:
- Option A: Parallel venation is generally found in monocots, not in the given dicot example of Colocasia. Smilax is an exception to the monocot rule and exhibits reticulate venation.
- Option C: Forward venation is not a standard term used to describe venation patterns.
- Option D: Lateral venation is not a standard term used to describe venation patterns.

Key Concepts:
- Venation types: Reticulate and Parallel
- Dicotyledonous vs. Monocotyledonous plants

Memory Aids:
- Reticulate: Think of a \"network\" or \"reticulum\" of veins.
- Parallel: Think of veins running parallel to each other.

Quick Tips:
- Remember that dicots generally have reticulate venation, while monocots generally have parallel venation. Smilax is an exception.

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Which of the following is the sink end of the plant?

View answer and explanation

Correct option: B

Cotyledon

Option B (Cotyledon) is correct because cotyledons act as storage organs and provide nourishment to the developing seedling, thus serving as a sink.

Solution approach

Correct Answer + Core Reason: Cotyledon. Cotyledons store food and act as a sink for nutrients during early plant development.

Step-by-Step Solution:

Step 1: Identify the function of each option in the plant.

Step 2: Stem tuber: Primarily a storage organ for carbohydrates, but not a primary sink during early development.

Step 3: Cotyledon: Seed leaves that provide nourishment to the developing seedling, acting as a sink.

Step 4: Leaf: Primarily a source of photosynthates, not a sink.

Step 5: Apical bud: A growing point, which is a sink, but cotyledons are the primary sink during germination.

Step 6: Conclude that cotyledons are the sink end of the plant.

Why other options are wrong:
- Option A: Stem tubers are storage organs, but not the primary sink during initial growth.
- Option C: Leaves are primarily sources of photosynthates, not sinks.
- Option D: Apical buds are sinks, but cotyledons are the initial and major sink during germination.

Key Concepts:
- Source-sink relationship in plants
- Function of cotyledons
- Plant development

Memory Aids:
- Remember that cotyledons are the \"baby food\" for the seedling.

Quick Tips:
- Think about the role of each plant part in providing or receiving nutrients.

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Most accurate function in the following statements about inflorescence is

View answer and explanation

Correct option: B

Formation of more fruit

Option B is correct because the primary function of an inflorescence is to facilitate the formation of more fruit by presenting flowers in a way that enhances pollination.

Solution approach

Correct Answer + Core Reason: Formation of more fruit. The primary function of an inflorescence is to facilitate pollination and thus, the formation of more fruit.

Step-by-Step Solution:

Step 1: Define inflorescence.

Step 2: Recall the functions of inflorescence.

Step 3: Identify the most accurate function from the given options.

Why other options are wrong:
- Option A: Dispersal of seeds is a function of the fruit, not the inflorescence itself.
- Option B: Formation of more fruit is the most accurate function of an inflorescence.
- Option C: Formation of pollen grains occurs in the anther, not the inflorescence.
- Option D: Dispersal of pollens is facilitated by the flower, and the inflorescence helps in presenting the flowers for pollination.

Key Concepts:
- Inflorescence function
- Pollination
- Fruit development

Memory Aids:
- Inflorescence = More Flowers = More Fruit

Quick Tips:
- Remember the relationship between inflorescence, pollination, and fruit formation.

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The examples of cellular endosperm are (1)
Citrus, Malea, Primula (2) Adoxa, Cetranthus,
Datura (3) Phoenix, Acer, Arachis (4)
Impatiens, Magnolia, Cetranthus

View answer and explanation

Correct option: C

2 and 4 are correct

Option C (2 and 4 are correct) is correct because Citrus, Malea, Primula exhibit nuclear endosperm, while Adoxa, Cetranthus, Datura, Impatiens, and Magnolia exhibit cellular endosperm.

Solution approach

Correct Answer + Core Reason: 2 and 4 are correct. These options list plants known to have cellular endosperm development.

Step-by-Step Solution:

Step 1: Understand the different types of endosperm development: cellular, nuclear, and helobial.

Step 2: Recall examples of plants exhibiting cellular endosperm development.

Step 3: Adoxa, Cetranthus, Datura, Impatiens, and Magnolia are known to have cellular endosperm.

Why other options are wrong:
- Option A (1, 2 and 3 are correct): Phoenix and Arachis have nuclear endosperm, not cellular.
- Option B (1 and 2 are correct): Citrus, Malea, and Primula have nuclear endosperm, not cellular.
- Option D (1 and 3 are correct): Citrus, Malea, Primula, Phoenix and Arachis have nuclear endosperm, not cellular.

Key Concepts:
- Endosperm development types: Cellular, Nuclear, Helobial
- Plant examples for each type of endosperm development

Memory Aids:
- None applicable for specific plant memorization, requires rote learning.

Quick Tips:
- Memorize plant examples for each type of endosperm development.

80 Hard

80 of 93Question permalink

Remembering +4 | -1

The flowers are Zygomorphic in:
(a) Mustard
(b) Gulmohar
(c) Cassia
(d) Datura
(e) Chilly
Choose the correct answer from the options given below:

View answer and explanation

Correct option: C

(b), (c) Only

Option C ((b), (c) Only) is correct because Gulmohar and Cassia exhibit zygomorphic flowers.

Solution approach

Correct Answer + Core Reason: (b), (c) Only. Gulmohar and Cassia have zygomorphic flowers.

Step-by-Step Solution:
Step 1: The question asks to identify the plants with zygomorphic flowers.
Step 2: Recall the definition of zygomorphic: Flowers that can be divided into two equal halves in only one plane.
Step 3: Gulmohar and Cassia have zygomorphic flowers.

Why other options are wrong:
- Option A: Datura and Chilly are not zygomorphic.
- Option B: Mustard is not zygomorphic.
- Option D: Datura and Chilly are not zygomorphic.

Key Concepts:
- Floral symmetry
- Zygomorphic flowers

Memory Aids:
- Remember that zygomorphic flowers have bilateral symmetry.

Quick Tips:
- Learn the different types of floral symmetry.

81 Hard

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The reproductive unit of angiosperms is

View answer and explanation

Correct option: C

Flower

Option C (Flower) is correct because the flower is the reproductive unit in angiosperms, responsible for sexual reproduction through pollination and fertilization.

Solution approach

Correct Answer + Core Reason: Flower. The flower is the reproductive unit of angiosperms.

Step-by-Step Solution:

Step 1: Define angiosperms: Angiosperms are flowering plants.

Step 2: Identify the reproductive unit: The flower is the reproductive unit in angiosperms, containing the sexual reproductive organs (stamens and pistils).

Why other options are wrong:
- Option A: Inflorescence is a group of flowers, not the individual reproductive unit.
- Option B: Floral buds are developing flowers, not the fully functional reproductive unit.
- Option D: Flower meristem is the tissue that gives rise to the flower, not the reproductive unit itself.

Key Concepts:
- Flower
- Angiosperms
- Sexual reproduction

Memory Aids:
- Flower = reproductive organ in flowering plants.

Quick Tips:
- Understand the basic structure and function of a flower.

82 Hard

82 of 93Question permalink

Remembering +4 | -1

Haustoria or sucking roots are found in

View answer and explanation

Correct option: A

Cuscuta

Option A (Cuscuta) is correct because Cuscuta uses haustoria to penetrate the host plant and absorb nutrients.

Solution approach

Correct Answer + Core Reason: Haustoria or sucking roots are found in Cuscuta, which uses them to extract nutrients from the host plant.

Step-by-Step Solution:

Step 1: Define \"haustoria.\"

Step 2: Understand the function of haustoria.

Step 3: Recall that Cuscuta is a parasitic plant.

Step 4: Recognize that Cuscuta uses haustoria to penetrate the host plant and absorb nutrients.

Step 5: Conclude that haustoria are found in Cuscuta.

Why other options are wrong:
- Option B: Betel is a vine that uses tendrils for support, not haustoria.
- Option C: Orchids are epiphytes and have aerial roots, but not haustoria.
- Option D: Tinospora is a climbing shrub, but does not have haustoria.

Key Concepts:
- Haustoria
- Parasitic plants
- Cuscuta

Memory Aids:
- Haustoria = Host sucker

Quick Tips:
- Remember that haustoria are characteristic of parasitic plants like Cuscuta.

83 Hard

83 of 93Question permalink

Understanding +4 | -1

[A]: Insectivorous plants grow in carbohydrate deficient soil.

[R]: Insectivorous plants grow in nitrogen rich soil.

View answer and explanation

Correct option: D

Both A and R are false

Option D (Both A and R are false) is correct because insectivorous plants grow in nutrient-deficient (especially nitrogen-deficient), not carbohydrate-deficient or nitrogen-rich, soils.

Solution approach

Correct Answer + Core Reason: Both A and R are false. Insectivorous plants grow in nutrient-poor, especially nitrogen-deficient, soils.

Step-by-Step Solution:

Step 1: Understand the habitat of insectivorous plants: They typically grow in soils lacking essential nutrients, particularly nitrogen.

Step 2: Assertion (A) states that insectivorous plants grow in carbohydrate-deficient soil, which is false. They need carbohydrates like any other plant.

Step 3: Reason (R) states that insectivorous plants grow in nitrogen-rich soil, which is also false. They grow in nitrogen-deficient soil and obtain nitrogen from insects.

Why other options are wrong:
- Option A: Both A and R are true and R is the correct explanation of A - Both A and R are false.
- Option B: Both A and R are true and R is not the correct explanation of A - Both A and R are false.
- Option C: A is true but R is false - Both A and R are false.

Key Concepts:
- Insectivorous plants
- Nutrient deficiency
- Nitrogen fixation

Memory Aids:
- Insectivorous plants eat insects to get nitrogen because the soil lacks it.

Quick Tips:
- Remember that insectivorous plants are adapted to nutrient-poor environments.

84 Hard

84 of 93Question permalink

Remembering +4 | -1

In hypogeal seed germination, the structure help to push the cotyledon inside the soil is

View answer and explanation

Correct option: A

Epicotyl

Option A (Epicotyl) is correct because in hypogeal germination, the epicotyl elongates, pushing the plumule up while the cotyledons remain below the soil surface.

Solution approach

Correct Answer + Core Reason: Epicotyl. In hypogeal germination, the epicotyl elongates to push the plumule above the soil.

Step-by-Step Solution:

Step 1: Define hypogeal germination: A type of seed germination in which the cotyledons remain below the soil surface.

Step 2: Define epicotyl: The portion of the embryonic axis above the cotyledons.

Step 3: Define hypocotyl: The portion of the embryonic axis below the cotyledons.

Step 4: Define plumule: The embryonic shoot.

Step 5: Define radicle: The embryonic root.

Step 6: Explain the process of hypogeal germination: In hypogeal germination, the epicotyl elongates, pushing the plumule above the soil surface while the cotyledons remain below.

Why other options are wrong:
- Option B: Hypocotyl elongates in epigeal germination, not hypogeal.
- Option C: Plumule is the embryonic shoot that is pushed up, not the structure that pushes.
- Option D: Radicle develops into the root system.

Key Concepts:
- Seed germination
- Hypogeal germination
- Epicotyl
- Hypocotyl

Memory Aids:
- Hypogeal = Ground (cotyledons stay on the ground)

Quick Tips:
- Remember the difference between hypogeal and epigeal germination.

85 Hard

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Remembering +4 | -1

The leaves are modified into tendrils, hook, pitcher and bladder in the following plants respectively

View answer and explanation

Correct option: A

Sweet pea, cat’s nail, Nepenthes, Utricularia

Option A (Sweet pea, cat’s nail, Nepenthes, Utricularia) is correct because sweet pea has tendrils, cat's nail has hooks, Nepenthes has pitchers, and Utricularia has bladders.

Solution approach

Correct Answer + Core Reason: Sweet pea, cat’s nail, Nepenthes, Utricularia. These plants have leaves modified into tendrils, hooks, pitchers, and bladders respectively.

Step-by-Step Solution:

Step 1: Recall the leaf modifications in each plant.

Step 2: Sweet pea has leaves modified into tendrils for climbing. Cat's nail (Uncaria tomentosa) uses hooks for climbing. Nepenthes (pitcher plant) has leaves modified into pitchers for trapping insects. Utricularia (bladderwort) has leaves modified into bladders for trapping small organisms.

Step 3: Match the modifications to the plants.

Step 4: Therefore, the correct sequence is Sweet pea, cat’s nail, Nepenthes, Utricularia.

Why other options are wrong:
- Option B: This option incorrectly assigns Utricularia to pitchers and Nepenthes to bladders.
- Option C: This option incorrectly assigns Nepenthes to tendrils and sweet pea to pitchers.
- Option D: This option incorrectly assigns Nepenthes to tendrils and sweet pea to hooks.

Key Concepts:
- Leaf modifications
- Plant adaptations

Memory Aids:
- Tendrils = Sweet Pea
- Hooks = Cat's Nail
- Pitchers = Nepenthes
- Bladders = Utricularia

Quick Tips:
- Know the specific leaf modifications in different plants.

86 Hard

86 of 93Question permalink

Remembering +4 | -1

Bracts enclosing a cluster of flowers are known as

View answer and explanation

Correct option: B

Involucre

Option B (Involucre) is correct because an involucre is a whorl of bracts that encloses a cluster of flowers.

Solution approach

Correct Answer + Core Reason: Involucre. Bracts enclosing a cluster of flowers are known as involucre.

Step-by-Step Solution:

Step 1: Understand the question: It asks about the term for bracts enclosing a cluster of flowers.

Step 2: Recall the different terms related to bracts and flower structures:
- Bracteate: Having bracts.
- Involucre: A whorl of bracts surrounding a flower cluster.
- Petaloid: Resembling petals.
- Polysepalous: Having separate sepals.

Step 3: Identify the correct term. An involucre is a whorl of bracts that surrounds and protects a cluster of flowers.

Why other options are wrong:
- Option A: Bracteate simply means having bracts, not specifically enclosing a flower cluster.
- Option C: Petaloid refers to structures resembling petals, not bracts.
- Option D: Polysepalous refers to having separate sepals, not bracts.

Key Concepts:
- Bracts
- Involucre
- Flower morphology

Memory Aids:
- *Involve* the bracts to *enclose* the flower cluster (Involucre).

Quick Tips:
- Remember that an involucre is a protective structure formed by bracts.

87 Hard

87 of 93Question permalink

Remembering +4 | -1

A root was described as adventitious root because it

View answer and explanation

Correct option: A

Arose from plumule

Option A (Arose from plumule) is correct because adventitious roots arise from parts of the plant other than the radicle, such as the plumule, stem, or leaves.

Solution approach

Correct Answer + Core Reason: Arose from plumule. Adventitious roots arise from parts other than the radicle.

Step-by-Step Solution:

Step 1: Understand the question: It asks about the defining characteristic of adventitious roots.

Step 2: Recall the definition of adventitious roots:
- Adventitious roots: Roots that develop from any part of the plant other than the radicle (embryonic root).
- Plumule: The embryonic shoot.

Step 3: Identify the correct characteristic. Adventitious roots arise from the plumule, stem, or leaves, not the radicle.

Why other options are wrong:
- Option B: Storage of food is a function of some roots, but not the defining characteristic of adventitious roots.
- Option C: Being swollen is a characteristic of some roots, but not the defining characteristic of adventitious roots.
- Option D: Growing in a marshy place describes a specific habitat, not the defining characteristic of adventitious roots.

Key Concepts:
- Adventitious roots
- Radicle
- Plumule
- Root morphology

Memory Aids:
- *Adventitious* roots arise from *ad*ditional places, not the radicle.

Quick Tips:
- Remember that adventitious roots can arise from stems, leaves, or even the plumule.

88 Hard

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Understanding +4 | -1

I. In dicotyledonous seeds, cotyledons are often fleshy and full of reserve food II. Generally, monocotyledonous seeds are endospermic III. Generally, dicotyledonous seeds are non-endospermic IV. Most of the monocotyledonous seeds have fleshy cotyledons. Select the correct statements

View answer and explanation

Correct option: D

All except IV

Option D (All except IV) is correct because monocotyledonous seeds typically have thin, papery cotyledons, not fleshy ones.

Solution approach

Correct Answer + Core Reason: All except IV. Monocotyledonous seeds generally have thin, papery cotyledons, not fleshy ones.

Step-by-Step Solution:

Step 1: Evaluate each statement.

Step 2: Statement I is correct: Dicotyledonous seeds often have fleshy cotyledons filled with reserve food.

Step 3: Statement II is correct: Monocotyledonous seeds are generally endospermic.

Step 4: Statement III is correct: Dicotyledonous seeds are generally non-endospermic.

Step 5: Statement IV is incorrect: Most monocotyledonous seeds have thin, papery cotyledons, not fleshy ones.

Why other options are wrong:
- Option A (All except I): Statement I is correct.
- Option B (All except II): Statement II is correct.
- Option C (All except III): Statement III is correct.

Key Concepts:
- Characteristics of dicotyledonous and monocotyledonous seeds.
- Endospermic vs. non-endospermic seeds.
- Cotyledon structure and function.

Memory Aids:
- None applicable, requires understanding of seed structure.

Quick Tips:
- Know the key differences between monocot and dicot seeds.

89 Hard

89 of 93Question permalink

Analyzing +4 | -1

Study the following statements and choose the correct option I.Buds are present in the axil of leaflets of the compound leaf II.Pulvinus leaf-base is present in some leguminous plants. III.In Alstonia, the petioles expand, become green and synthesize food IV.Opposite phyllotaxy is seen in guava

View answer and explanation

Correct option: A

II and IV are correct but I and III are wrong

Option A (II and IV are correct but I and III are wrong) is correct because buds are present in the axil of the entire compound leaf, not leaflets, pulvinus leaf-base is present in leguminous plants, petioles do not expand and synthesize food in Alstonia, and opposite phyllotaxy is seen in guava.

Solution approach

Correct Answer + Core Reason: II and IV are correct but I and III are wrong. Statements II and IV are factually correct, while I and III are incorrect.

Step-by-Step Solution:

Step 1: Analyze statement I.\nBuds are present in the axil of leaflets of the compound leaf. This is incorrect; buds are present in the axil of the entire compound leaf, not the leaflets.

Step 2: Analyze statement II.\nPulvinus leaf-base is present in some leguminous plants. This is correct.

Step 3: Analyze statement III.\nIn Alstonia, the petioles expand, become green and synthesize food. This is incorrect; this is a characteristic of phyllode, not typically seen in Alstonia.

Step 4: Analyze statement IV.\nOpposite phyllotaxy is seen in guava. This is correct.

Step 5: Identify the correct option.\nStatements II and IV are correct, while I and III are wrong.

Why other options are wrong:
- Option B: I and III are correct but II and IV are wrong - I and III are incorrect.
- Option C: I and IV are correct but II and III are wrong - I and III are incorrect.
- Option D: II, III and IV are correct but I is wrong - III is incorrect.

Key Concepts:
- Leaf morphology
- Compound leaves
- Pulvinus leaf base
- Phyllode
- Phyllotaxy

Memory Aids:
- Remember that buds are at the base of the *entire* compound leaf.

Quick Tips:
- Pay attention to the specific terminology related to leaf structures and arrangements.

90 Hard

90 of 93Question permalink

Understanding +4 | -1

A pome fruit is said to be false because

View answer and explanation

Correct option: C

Its actual fruit is located within an edible fl eshy thalamus

Option C (Its actual fruit is located within an edible fleshy thalamus) is correct because a pome fruit is considered a false fruit as the fleshy edible part is derived from the thalamus, not the ovary wall (pericarp).

Solution approach

Correct Answer + Core Reason: Its actual fruit is located within an edible fleshy thalamus. Pome fruits are false fruits because the fleshy part is the thalamus.

Step-by-Step Solution:

Step 1: Define a true fruit: A fruit that develops from the ovary.

Step 2: Define a false fruit: A fruit in which other floral parts contribute to the fruit structure.

Step 3: Describe a pome fruit (e.g., apple, pear): The core is the true fruit (developed from the ovary), while the fleshy part is the thalamus.

Step 4: Explain why a pome is a false fruit: Because the main edible part is derived from the thalamus, not the ovary.

Why other options are wrong:
- Option A (Its pericarp is inconspicuous): While the pericarp may be less prominent, this is not the primary reason it's a false fruit.
- Option B (Its endocarp is cartilaginous): The cartilaginous endocarp is a characteristic of pome fruits but does not define them as false fruits.
- Option D (It develops from an inferior ovary): While many pome fruits develop from inferior ovaries, this alone does not make them false fruits. Many true fruits also develop from inferior ovaries.

Key Concepts:
- True vs. False fruits
- Pome fruit structure
- Thalamus
- Ovary

Memory Aids:
- Pome = Primarily Thalamus

Quick Tips:
- Remember that false fruits involve floral parts other than the ovary contributing to the fruit structure.

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