Assertion & Reason Test: Morphology of Flowering Plants - Grade 11 MCQ

In vexillary type of aestivation, the posterior petal is the largest and covers almost the two lateral petals, and the latter in their turn, nearly overlap the two anterior or smallest petals. e.g, pea. This type of gestational is also called as descending imbricate aestivation.

Topic in NCERT: Aestivation

Line in NCERT: "In pea and bean flowers, there are five petals, the largest (standard) overlaps the two lateral petals (wings) which in turn overlap the two smallest anterior petals (keel); this type of aestivation is known as vexillary or papilionaceous."

In vexillary type of aestivation, the posterior petal is the largest and covers almost the two lateral petals, and the latter in their turn, nearly overlap the two anterior or smallest petals. e.g, pea. This type of gestational is also called as descending imbricate aestivation.

Topic in NCERT: Aestivation

Line in NCERT: "In pea and bean flowers, there are five petals, the largest (standard) overlaps the two lateral petals (wings) which in turn overlap the two smallest anterior petals (keel); this type of aestivation is known as vexillary or papilionaceous."

In perigynous flowers , ovary is situated at the centre and other parts are on the rim of the thalamus hence, ovary is called half-inferior.

Topic in NCERT: Position of floral parts on thalamus

Line in NCERT: "The ovary here is said to be half inferior, e.g., plum, rose, peach."

The assertion is true as in monocotyledonous plants, the primary root is indeed short-lived and is replaced by a fibrous root system originating from the base of the stem. The reason is also true and correctly explains the assertion because the fibrous root system provides a more extensive network for efficient water and nutrient absorption from the soil.

Topic in NCERT: THE ROOT

Line in NCERT: "In monocotyledonous plants, the primary root is short lived and is replaced by a large number of roots. These roots originate from the base of the stem and constitute the fibrous root system, as seen in the wheat plant."

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
In imbricate aestivation one petal is completely inward, one petal is completely outward, one margin is internal and another margin is external.
Examples of ascending imbricate is Cassia and gulmohar not the reason.
So, the correct answer is B.
 

Topic in NCERT: Aestivation

Line in NCERT: "In Cassia and gulmohur, the aestivation is called imbricate."

Actinomorphic flowers are those flowers which can be divided into two equal halves along any plane of symmetry passing through the central axis. These flowers show radial symmetry, and not bilateral symmetry. For example, Datura, mustard and chilli.
Those flowers which can be divided into two equal halves (right and left) only along a single plane of symmetry passing through the central axis are known as zygomorphic flowers. For example, Cassia and gulmohur.
Hence, both assertion and reason statements are incorrect.
The correct option is C If both assertion and reason are false.

Topic in NCERT: THE FLOWER

Line in NCERT: "When a flower can be divided into two similar halves only in one particular vertical plane, it is zygomorphic."

The assertion is true as roots in some plants are indeed modified to perform additional functions beyond their primary roles of absorption and conduction. The reason accurately explains the assertion by listing examples of such modifications, including storage of food (e.g., in carrots), providing support (e.g., prop roots in banyan trees), and aiding in respiration (e.g., pneumatophores in mangroves).

Topic in NCERT: MODIFIED ROOTS IN PLANTS

Line in NCERT: "The roots in some plants get modified for storage of food, mechanical support and respiration."

In perigynous flowers , ovary is situated at the centre and other parts are on the rim of the thalamus hence, ovary is called half-inferior.

Topic in NCERT: Position of floral parts on thalamus

Line in NCERT: "The ovary here is said to be half inferior, e.g., plum, rose, peach."

The assertion is true as in monocotyledonous plants, the primary root is indeed short-lived and is replaced by a fibrous root system originating from the base of the stem. The reason is also true and correctly explains the assertion because the fibrous root system provides a more extensive network for efficient water and nutrient absorption from the soil.

Topic in NCERT: THE ROOT

Line in NCERT: "In monocotyledonous plants, the primary root is short lived and is replaced by a large number of roots. These roots originate from the base of the stem and constitute the fibrous root system, as seen in the wheat plant."

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
In imbricate aestivation one petal is completely inward, one petal is completely outward, one margin is internal and another margin is external.
Examples of ascending imbricate is Cassia and gulmohar not the reason.
So, the correct answer is B.
 

Topic in NCERT: Aestivation

Line in NCERT: "In Cassia and gulmohur, the aestivation is called imbricate."

Actinomorphic flowers are those flowers which can be divided into two equal halves along any plane of symmetry passing through the central axis. These flowers show radial symmetry, and not bilateral symmetry. For example, Datura, mustard and chilli.
Those flowers which can be divided into two equal halves (right and left) only along a single plane of symmetry passing through the central axis are known as zygomorphic flowers. For example, Cassia and gulmohur.
Hence, both assertion and reason statements are incorrect.
The correct option is C If both assertion and reason are false.

Topic in NCERT: THE FLOWER

Line in NCERT: "When a flower can be divided into two similar halves only in one particular vertical plane, it is zygomorphic."

The assertion is true as roots in some plants are indeed modified to perform additional functions beyond their primary roles of absorption and conduction. The reason accurately explains the assertion by listing examples of such modifications, including storage of food (e.g., in carrots), providing support (e.g., prop roots in banyan trees), and aiding in respiration (e.g., pneumatophores in mangroves).

Topic in NCERT: MODIFIED ROOTS IN PLANTS

Line in NCERT: "The roots in some plants get modified for storage of food, mechanical support and respiration."