The correct option is
B. is formed from an ovary.
Detailed Explanation:
- Understanding the Definitions:
- Fruit: In botanical terms, a fruit is the mature ovary of a flower, usually containing seeds. It develops from the fertilized ovary after pollination.
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Seed: A seed is a fertilized ovule that contains the embryo of a plant, along with stored food (endosperm) and a protective seed coat.
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Maize Grain as a Fruit:
- The maize grain, commonly referred to as a kernel, is indeed classified as a fruit because it develops from the ovary of the maize flower after fertilization. The ovary wall thickens and matures into the pericarp (the outer layer of the fruit), which encases the seed (the kernel).
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In maize, the entire kernel is often referred to as a "caryopsis," which is a type of dry fruit where the seed coat is fused with the fruit wall. This is a characteristic feature of grains.
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Why Option B is Correct:
- Since the maize grain is formed from the ovary of the flower, it meets the botanical definition of a fruit. The ovary contains the ovules, which develop into seeds after fertilization. Therefore, the maize grain is a fruit because it is the mature ovary that contains the seeds.
Why the Other Options are Incorrect:
- Option A: has a large endosperm:
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While it is true that maize grains have a large endosperm, this characteristic alone does not define whether it is a fruit or a seed. Many seeds have varying amounts of endosperm, and the presence of a large endosperm does not change the classification of the maize grain as a fruit.
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Option C: is a monocotyledon:
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The classification of maize as a monocotyledon (a plant with one seed leaf) is a taxonomic characteristic and does not directly relate to whether the maize grain is a fruit or a seed. Monocots can produce both fruits and seeds, so this option does not address the question.
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Option D: has no plumule and radicle:
- The terms "plumule" and "radicle" refer to parts of a seed. The maize grain does contain these structures, but they are not relevant to the classification of the grain as a fruit. The presence or absence of these structures does not determine whether the maize grain is a fruit or a seed.
Summary:
- The maize grain is classified as a fruit because it develops from the ovary of the flower.
- The ovary contains seeds, which are the fertilized ovules.
- Other options do not accurately address the botanical definition of fruit versus seed.
- Understanding the definitions and characteristics of fruits and seeds is crucial for proper classification in botany.
Revision Summary:
- A fruit is the mature ovary of a flower, while a seed is a fertilized ovule.
- The maize grain is a fruit because it forms from the ovary after fertilization.
- Characteristics like endosperm size, monocot classification, and seed structures do not determine fruit status.
- Always refer to botanical definitions for accurate classifications in plant biology.