Test: Phanerogams - Class 9 MCQ

Secondary growth occurs when dicot stems and roots grow wider. Frequently, this involves the development of a woody stem, which arises from a combination of the activities of the stem’s vascular cambium and cork meristem tissues.

The rose plant belongs to the group of dicots. Here is a detailed explanation:
Characteristics of the rose plant:
- Reticulate venation: The leaves of the rose plant have reticulate venation, which means that the veins form a network-like pattern on the leaf surface.
- Multiple cotyledons: Dicots have two cotyledons (seed leaves) in their embryos, and the rose plant also has two cotyledons.
- Floral parts in multiples of four or five: Dicots typically have floral parts (such as petals, sepals, and stamens) in multiples of four or five, and the rose plant follows this characteristic.
- Taproot system: Dicots have a taproot system, where a single main root grows deep into the soil and gives rise to lateral roots. The rose plant also possesses a taproot system.
Why the rose plant is not classified into other groups:
- Thallophytes: Thallophytes are a group of plants that lack true leaves, stems, and roots. The rose plant has well-developed leaves, stems, and roots, so it does not belong to this group.
- Monocots: Monocots have leaves with parallel venation, while the rose plant has reticulate venation. Therefore, the rose plant cannot be classified as a monocot.
- Gymnosperms: Gymnosperms are plants that bear naked seeds. The rose plant, on the other hand, bears seeds within a fruit, making it a dicot rather than a gymnosperm.
In conclusion, based on its reticulate venation, two cotyledons, floral parts in multiples of four or five, and taproot system, the rose plant belongs to the group of dicots.

Characteristics of dicots are as follows:

1. These plants have two cotyledons in their seeds.
2. Their leaves are broad and have reticulate venation.
3. They have tap roots.
    

Sunflower is a pentamerous flower having five or multiple of five petals.

Shared Feature of Angiosperms and Gymnosperms: Presence of Seeds
- Both angiosperms and gymnosperms are seed-bearing plants, which means they reproduce through the production of seeds.
- Seeds are structures produced by plants that contain an embryonic plant, stored nutrients, and a protective outer covering.
- The presence of seeds is a significant feature that distinguishes both angiosperms and gymnosperms from other plant groups.
Differences between Angiosperms and Gymnosperms:
Angiosperms:
- Angiosperms are flowering plants that produce flowers as part of their reproductive structures.
- Flowers are the reproductive organs of angiosperms, and they play a crucial role in the fertilization process.
- Angiosperms have enclosed seeds, which are protected within a fruit.
- Fruits are mature ovaries that develop after fertilization and help in seed dispersal.
- Angiosperms have a more advanced vascular system, with vessels that transport water, nutrients, and sugars.
Gymnosperms:
- Gymnosperms include plants such as conifers, cycads, and ginkgoes.
- Gymnosperms do not produce flowers; instead, they have reproductive structures called cones.
- Cones are structures that contain the reproductive organs of gymnosperms, including male pollen cones and female seed cones.
- Gymnosperms have exposed seeds, which are not enclosed within a fruit.
- Gymnosperms have a simpler vascular system compared to angiosperms, with tracheids that transport water and nutrients.
In summary, while angiosperms and gymnosperms share the common feature of seed production, they differ in terms of their reproductive structures (flowers vs. cones) and the protection of their seeds (enclosed within a fruit vs. exposed).

Examples of dicot plants:



1. Pea: Pea plants are dicots and belong to the family Fabaceae. They have compound leaves and produce pods that contain multiple seeds.



2. Rose: Roses are dicots and belong to the family Rosaceae. They have compound leaves and produce fragrant flowers with multiple petals.



3. Neem: Neem trees are dicots and belong to the family Meliaceae. They have pinnate leaves and produce small white flowers.



4. Both (a) and (b): The correct answer is option (d) - both pea and rose are examples of dicot plants.



Explanation:

- Dicot plants, also known as dicotyledonous plants, are a group of flowering plants that have two cotyledons or seed leaves.

- They are characterized by having reticulate veins in their leaves, taproots, and flower parts in multiples of four or five.

- Dicot plants include a wide range of species, including trees, shrubs, and herbaceous plants.

- Examples of dicot plants can be found in various plant families, such as Fabaceae (pea), Rosaceae (rose), and Meliaceae (neem).

- Pea plants have compound leaves and produce pods with multiple seeds, while roses have compound leaves and produce beautiful flowers with multiple petals.

- Neem trees have pinnate leaves and small white flowers.

- Therefore, options (a) and (b) are both correct examples of dicot plants.



In conclusion, dicot plants encompass a diverse range of species and can be found in different plant families. Pea, rose, and neem are all examples of dicots, showcasing the various characteristics and adaptations of these plants.

Leaves in Dicot Plants and their Venation
Dicot plants, also known as dicotyledonous plants, are a type of flowering plants that have two cotyledons or embryonic leaves in their seeds. These plants exhibit a variety of leaf venation patterns, which refers to the arrangement of veins on the leaf surface. The venation pattern is an important characteristic used to classify plants into different groups.
Reticulate Venation
- Reticulate venation is the most common type of leaf venation pattern found in dicot plants.
- In this pattern, the veins form a network-like structure, branching and reticulating throughout the leaf.
- The main veins, called midribs, give rise to smaller veins called secondary veins, which further branch into tertiary veins.
- Examples of dicot plants with reticulate venation include mango, rose, and oak trees.
Parallel Venation
- Parallel venation is another type of leaf venation pattern, but it is more commonly found in monocot plants.
- In parallel venation, the veins run parallel to each other from the base of the leaf to the tip.
- Examples of monocot plants with parallel venation include grasses, lilies, and banana plants.
- While parallel venation is not typically found in dicot plants, there are some exceptions such as the banana tree.
No Venation
- It is incorrect to say that dicot plants have no venation because venation is a characteristic feature of leaves in all vascular plants.
- Venation refers to the arrangement of veins, which are essential for transporting water, nutrients, and sugars throughout the leaf.
Spines on Leaves
- The presence of spines on leaves is not directly related to venation but rather a separate characteristic.
- Some dicot plants, such as cacti, have modified leaves called spines, which serve as a defense mechanism against herbivores.
- Spines are sharp and often prevent animals from feeding on the plant.
In conclusion, the correct answer is D: Reticulate venation. Dicot plants typically exhibit reticulate venation, where the veins form a branching network throughout the leaf. While parallel venation is more common in monocot plants, it can also be found in some dicots like the banana tree. It is important to note that all dicot plants have venation, and the presence of spines on leaves is a separate characteristic unrelated to venation.

Angiosperms that bear parallel venation in leaves and fibrous roots are called monocots.

1. Pteridophytes: Pteridophytes are a group of vascular plants that include ferns, horsetails, and clubmosses. They have true roots, stems, and leaves, but their leaves do not have parallel venation.


2. Ferns: Ferns are a type of pteridophyte and do not have parallel venation in their leaves. They typically have compound leaves with pinnate or palmate venation.


3. Monocots: Monocots are a group of angiosperms that have one cotyledon in their seeds. They include plants like grasses, lilies, and orchids. Monocots have leaves with parallel venation and fibrous roots.


4. Dicots: Dicots are another group of angiosperms that have two cotyledons in their seeds. They include plants like roses, sunflowers, and oak trees. Dicots have leaves with reticulate or netted venation and taproots or other types of roots, but not fibrous roots.

Therefore, the correct answer is Monocots (C).

Explanation:
Gymnosperms are a group of seed-producing plants that do not produce flowers. They have unique characteristics when it comes to their seeds. The correct option describing the seeds present in Gymnosperms is B: In Gymnosperms, the seeds are naked.
Here are the key points explaining why option B is correct:
- Gymnosperms have naked seeds, which means that the seeds are not enclosed within a protective fruit like in angiosperms (flowering plants).
- The term "naked seeds" refers to the fact that the seeds of Gymnosperms are not covered or protected by any additional structures. They are directly exposed to the environment.
- Instead of being enclosed in fruits, the seeds in Gymnosperms are typically found in specialized structures called cones or strobili.
- Gymnosperms include various plant species such as conifers (e.g., pine trees), cycads, ginkgoes, and gnetophytes.
- These plants have evolved unique adaptations to protect their naked seeds, such as the scales of pine cones or the fleshy arils of certain yews.
In summary, Gymnosperms have naked seeds that are not enclosed in fruits, which differentiates them from angiosperms.

Answer:
Pentamerous flowers:
- Pentamerous flowers are flowers that have their parts, such as petals, sepals, and stamens, in multiples of five.
- The term "pentamerous" comes from the Greek words "penta" meaning five and "meros" meaning part.
Number of petals in pentamerous flowers:
- In pentamerous flowers, the number of petals is typically five or a multiple of five.
- The petals are the colorful, often leaf-like structures that make up the outer part of the flower.
- They are usually arranged in a circular or radial pattern around the center of the flower.
Correct Answer:
The correct answer is B: Five.
- Pentamerous flowers have five petals or a multiple of five petals.
- This means that the number of petals in pentamerous flowers can be 5, 10, 15, 20, and so on.
Explanation:
- The term "pentamerous" specifically refers to flowers with parts in multiples of five.
- While there can be variations in the number of petals in some flowers, the basic structure of pentamerous flowers follows the pentamerous pattern with five petals or a multiple of five.
- This structural arrangement is a characteristic feature of many flowering plants and helps in their classification and identification.
Summary:
- Pentamerous flowers have their parts in multiples of five.
- The number of petals in pentamerous flowers is typically five or a multiple of five.
- Therefore, the correct answer is B: Five.

The reproductive part of an angiospermic plant is a flower.
Angiosperms, also known as flowering plants, have a unique reproductive structure called a flower. The flower is the reproductive organ of the plant and is responsible for producing seeds and fruits. Here is a detailed explanation of the flower's structure and function:
Flower Structure:
- Receptacle: The base of the flower where all the other parts are attached.
- Petals: Colorful and attractive structures that surround the reproductive organs. They help in attracting pollinators.
- Sepals: Leaf-like structures that protect the flower bud before it opens.
- Stamen: The male reproductive part of the flower, consists of anthers and filaments.
- Anthers: Pollen-producing structures located at the top of the stamen.
- Filaments: Thin stalks that support the anthers.
- Carpel/Pistil: The female reproductive part of the flower.
- Stigma: The sticky structure at the top of the carpel that receives pollen.
- Style: The slender tube-like structure that connects the stigma to the ovary.
- Ovary: The swollen base of the carpel that contains ovules.
- Ovules: Structures within the ovary that develop into seeds after fertilization.
Flower Function:
- Pollination: Flowers produce pollen, which is transferred to the stigma of another flower through various agents like wind, water, insects, birds, or mammals.
- Fertilization: Once the pollen lands on the stigma, it travels down the style to reach the ovary, where fertilization takes place. The male gametes from the pollen combine with the female gametes in the ovules.
- Seed Production: After fertilization, the ovules develop into seeds within the ovary. The ovary then matures to form a fruit that protects the seeds.
- Seed Dispersal: Fruits aid in the dispersal of seeds away from the parent plant, increasing the chances of successful germination and survival.
In conclusion, the flower is the reproductive part of an angiospermic plant. Its various structures and functions ensure the successful reproduction and dispersal of seeds for the plant's survival and propagation.

Plants with Naked Embryos and Vascular Tissue
- The correct answer to the question is Pteridophytes.
- Pteridophytes are a group of plants that have naked embryos (embryos not enclosed within a protective seed coat) and vascular tissue (xylem and phloem).
- These plants are commonly referred to as ferns and fern allies.
- Pteridophytes are characterized by their ability to reproduce via spores instead of seeds.
- They have specialized tissues for conducting water (xylem) and nutrients (phloem) throughout the plant.
- Unlike bryophytes (such as mosses and liverworts), pteridophytes have true vascular tissue, which allows them to grow larger and more complex.
- Pteridophytes play a significant role in the ecosystem as they contribute to soil stabilization, water retention, and provide habitats for various organisms.
- Some common examples of pteridophytes include ferns, horsetails, and club mosses.
- Pteridophytes are an important group of plants in botanical studies and have both ecological and economic importance.

Trimerous flowers are found in Monocots.
Explanation:
- Trimerous flowers refer to flowers that have their floral organs arranged in multiples of three.
- Monocots are a type of flowering plants that have a single cotyledon (seed leaf) in their embryos.
- Monocots include plants like grasses, lilies, orchids, and palms.
- These plants typically have parallel-veined leaves, scattered vascular bundles in their stems, and flower parts in multiples of three.
- Trimerous flowers are a characteristic feature of monocots, where the floral organs such as petals, sepals, and stamens are arranged in groups of three or multiples of three.
- On the other hand, dicots have flowers with floral organs typically arranged in groups of four or five.
- Therefore, the correct answer is B: Monocots.

In the given options, Rice, Maize, Wheat  all are grains. But the Potato is not a grain, it is considered as a vegetable. So here, the odd one is potato.

The flower has nine petals ( a multiple of three) . This is a characteristic of Monocot group.