Assertion (A): Mango and coconut fruits are botanically classified as drupes. Reason (R): Both mango and coconut fruits develop from monocarpellary superior ovaries and are one-seeded.
Both mango and coconut are drupes because they develop from monocarpellary superior ovaries and contain a single seed. Hence, the Reason correctly explains the Assertion.
Question 292 of 300
📘 CLASS XI
Assertion (A): In a mature non-endospermic seed of pea or gram, endosperm is absent. Reason (R): In these plants, the endosperm is completely consumed by the developing embryo during seed development.
Pea and gram are non-endospermic seeds because the endosperm is completely consumed during embryo development. Therefore, the Reason correctly explains the Assertion.
Question 293 of 300
📘 CLASS XI
Assertion (A): In a maize seed, the embryo is separated from the bulky endosperm by a proteinous layer called the aleurone layer. Reason (R): Maize is a monocotyledonous seed where the single shield-shaped cotyledon is known as the scutellum.
The aleurone layer is the protein-rich outer layer of the endosperm in maize, while the scutellum is the single shield-shaped cotyledon of the monocot embryo. Both statements are true, but the presence of the scutellum does not explain the aleurone layer.
Question 294 of 300
📘 CLASS XI
Assertion (A): Solanaceae is commonly referred to as the potato family and is widely distributed in tropical, subtropical, and temperate regions. Reason (R): All plants belonging to Solanaceae exhibit zygomorphic flowers and non-endospermic seeds.
Solanaceae is known as the potato family and is widely distributed in tropical, subtropical, and temperate regions. However, its flowers are actinomorphic and the seeds are endospermic. Therefore, the Reason is false.
Question 295 of 300
📘 CLASS XI
Assertion (A): Katherine Esau’s publication Plant Anatomy completely revived interest in the discipline of plant biology and had an enormous impact worldwide. Reason (R): The book moved away from purely descriptive structural lists and instead took a dynamic, developmental approach designed to enhance the functional understanding of plant structure.
Before Esau's landmark work, plant anatomy was largely descriptive. Her 1954 book introduced a dynamic and developmental approach, revitalizing worldwide interest in plant anatomy.
Question 296 of 300
📘 CLASS XI
Assertion (A): A developmental biologist will never observe a lateral branch or a vegetative shoot originating from the axil of an individual leaflet in a compound leaf like neem. Reason (R): While axillary buds are present in the axil of the petiole in both simple and compound leaves, they are completely absent in the axils of the individual leaflets of a compound leaf.
Branches arise from axillary buds. Since leaflets lack axillary buds, branches cannot originate from the axil of an individual leaflet, whereas the main petiole possesses an axillary bud.
Question 297 of 300
📘 CLASS XI
Assertion (A): When a vegetative shoot tip transitions into a flower, the resulting reproductive structure is always solitary and cannot continue to grow as a leafy shoot. Reason (R): During the transition, the shoot apical meristem is completely converted into a floral meristem, which condenses the axis and prevents the elongation of internodes.
A flower is a modified shoot. The shoot apical meristem is transformed into a floral meristem, terminating vegetative growth and producing a solitary flower.
Question 298 of 300
📘 CLASS XI
Assertion (A): Plants possessing long, thin, and flexible petioles are physiologically better adapted to survive in hot, windless microclimates than plants with short, rigid petioles. Reason (R): Long, thin, and flexible petioles allow leaf blades to flutter easily in light breezes, which cools the leaf lamina and brings a continuous supply of fresh air to the leaf surface.
Flexible petioles enable leaf fluttering, which cools the leaf and continuously supplies fresh air to the leaf surface, improving physiological efficiency.
Question 299 of 300
📘 CLASS XI
Assertion (A): In parietal placentation, such as in mustard and Argemone, the ovary is developmentally unilocular but functionally behaves as bilocular. Reason (R): The ovules are initially borne on the peripheral parts or the inner wall of a single chamber, which subsequently gets partitioned into two chambers by the formation of a false septum.
Parietal placentation is initially unilocular, but the formation of a false septum divides the ovary into two functional chambers, explaining its bilocular appearance.
Question 300 of 300
📘 CLASS XI
Assertion (A): It is a morphological misconception to assume that all monocotyledonous seeds are endospermic and all dicotyledonous seeds are non-endospermic. Reason (R): While the majority of monocot seeds store food in an endosperm, orchids are monocots that produce non-endospermic seeds; conversely, castor is a dicotyledonous seed that retains its endosperm at maturity.
The generalization is incorrect because orchids are non-endospermic monocots, whereas castor is an endospermic dicot. These exceptions directly support the assertion.
