All questions of Reproduction in Plants for Class 7 Exam

Introduction to Flower Structure
In the reproductive system of flowering plants, different parts play specific roles. Understanding these roles helps us grasp how flowers develop into fruits.
Components of a Flower
- Stamen: The male reproductive part, consisting of an anther and filament, produces pollen.
- Pistil: The female reproductive part, which includes the ovary, style, and stigma.
- Ovary: Located at the base of the pistil, the ovary is crucial for fruit development.
Role of the Ovary in Fruit Development
- Fertilization: After pollination, when pollen reaches the stigma, it travels down to fertilize the ovules in the ovary.
- Transformation: Once fertilization occurs, the ovary begins to transform.
- Fruit Formation: The ovary develops into a fruit, which protects the seeds and aids in their dispersal.
Understanding the Fruit
- Function of Fruits: Fruits serve to protect seeds and facilitate their spread through various means (animals, wind, water).
- Types of Fruits: Depending on the species, fruits can be fleshy (like apples) or dry (like nuts).
Conclusion
In summary, the correct answer to which part of the flower develops into a fruit is option B: Ovary. The ovary's transformation into fruit is essential for the plant's reproductive success, ensuring that seeds are protected and distributed effectively.

B

The flower is the primary reproductive part of a plant. It contains the organs necessary for sexual reproduction, including the stamens (male organs) and pistils (female organs).

Pollen Grains and Their Transport
Pollen grains are a crucial part of the reproduction process in flowering plants. They are responsible for transferring male gametes to female structures for fertilization. The statement that pollen grains can be carried by wind or water for pollination is indeed true. Here's why:
Wind Pollination
- Many plants have adapted to use wind as a primary mode of pollen transport.
- These plants produce lightweight, dry pollen grains that can easily be carried over long distances by air currents.
- Examples include grasses, conifers, and many trees.
Water Pollination
- While less common, some aquatic plants utilize water for pollination.
- In these cases, pollen grains can float on water surfaces and be carried to female flowers.
- Examples of such plants include certain species of water lilies and seagrasses.
Importance of Pollination
- Effective pollination is essential for the reproduction of many plant species, leading to fruit and seed production.
- This process not only supports plant life but also sustains ecosystems and food chains.
Conclusion
The ability of pollen grains to be transported by wind or water highlights the diverse strategies plants employ for successful reproduction. Understanding these mechanisms is vital for appreciating plant biology and ecology. Thus, the correct answer to the statement is option 'A' - True.

False. Reason:
There would be severe competition for sunlight, water, minerals and space. It also enables the plants to invade new habitats for wider distribution. The seeds would not grow into healthy plants.
There will be shortage of space for the germination of the seeds. Even if they germinate, they cannot grow properly due to scarcity of food resources and also space. Thus some of them will fail to grow.

When the Pollen grains land on the stigma of a flower of a different plant of the same species it is known as cross pollination.
when pollen grains land on the stigma of a flower of the same plant or another flower on the same plant it is known as self pollination.

Understanding Plant Reproduction
Plants have diverse methods of reproduction, and they do not rely solely on sexual means. Here’s a detailed explanation of why the statement is false.
1. Sexual Reproduction
- Involves the fusion of male and female gametes.
- Produces seeds that can grow into new plants.
- Examples include flowering plants (angiosperms) and conifers (gymnosperms).
2. Asexual Reproduction
- Does not involve gametes; instead, new plants grow from parts of the parent plant.
- Methods include:
- Vegetative Propagation: New plants grow from stems, roots, or leaves. Examples are potatoes (from tubers) and strawberries (from runners).
- Cuttings: A piece of a parent plant, like a stem or leaf, can grow into a new plant.
- Layering: A branch is bent to the ground, covered with soil, and roots develop.
- Division: The parent plant is split into multiple parts, each capable of growing independently.
3. Advantages of Asexual Reproduction
- Rapid production of new plants.
- No need for pollinators or specific environmental conditions.
- Genetic uniformity, ensuring that successful traits are passed on.
4. Conclusion
The ability of plants to reproduce both sexually and asexually allows them to adapt and thrive in various environments. Therefore, the statement that plants can reproduce only through sexual means is indeed false. Plants are remarkable in their reproductive strategies, ensuring their survival and diversity.

Understanding Cacti and Detachment
When parts of a cactus get detached, they can give rise to new plants, which is a form of asexual reproduction. This ability is particularly significant in arid environments where cacti thrive.
How Cacti Reproduce
- Cacti can reproduce through a process called vegetative propagation.
- When segments of a cactus, such as pads or branches, break off, they can take root and grow into a new plant.
Benefits of This Process
- Survival: This method allows cacti to quickly colonize their environment, ensuring survival in harsh conditions.
- Root Formation: Detached parts can develop roots when in contact with soil, drawing water and nutrients necessary for growth.
Conditions for Successful Propagation
- Moisture: The detached part must be in a suitable environment with enough moisture to encourage root development.
- Sunlight: Adequate sunlight is essential for the new plant to photosynthesize and grow properly.
Conclusion
In summary, when cacti parts are detached, they can produce new plants, enabling them to spread and thrive in their ecosystems. This reproductive strategy is vital for their survival and adaptation in challenging environments.

Unisexual flowers contain either male (stamens) or female (pistils) reproductive organs, but not both. This promotes cross-pollination, which can lead to greater genetic diversity in the offspring.

Pollen Grain Formation in Flowering Plants
In flowering plants, the formation of pollen grains occurs specifically in the anther, which is part of the stamen. Here’s a more detailed look at the process:
Location of Pollen Grain Formation
- The anther is the male reproductive part of the flower, situated at the top of the stamen.
- Each anther contains pollen sacs, where pollen grains develop and mature.
Process of Pollen Formation
- Inside the anther, there are specialized cells called microsporocytes.
- These microsporocytes undergo meiosis to form haploid microspores.
- Each microspore then develops into a pollen grain through a process known as microgametogenesis.
Importance of Pollen Grains
- Pollen grains are crucial for the reproduction of flowering plants as they carry male gametes.
- They are transferred to the stigma of a flower (part of the pistil) during pollination, enabling fertilization.
Summary
- The anther is the site of pollen grain formation, making option 'B' the correct answer.
- Understanding the role of the anther helps in grasping how flowering plants reproduce effectively.
By recognizing the function of the anther, students can appreciate the complexity of plant reproduction and the importance of pollen in the life cycle of flowering plants.

Differences Between Vegetative Propagation and Seed Production
When comparing new plants produced by vegetative propagation to those produced from seeds, several key differences emerge, particularly regarding growth time and flowering.
Faster Growth and Early Fruiting
- Rapid Development: Plants grown through vegetative propagation typically take less time to develop. This is because they are clones of the parent plant, inheriting the same genetic material. As a result, they already possess the traits necessary for growth.
- Early Flowering and Fruiting: These plants often bear flowers and fruits sooner than seed-grown plants. Since they do not need to go through the process of germination and early development from a seed, they can allocate energy to reproduction much faster.
Other Options Explained
- Exact Copies: Option B states that plants from vegetative propagation are not exact copies of the parent plant. This is incorrect; they are indeed genetic clones.
- Multiple Parents: Option C suggests they are produced from multiple parents. In vegetative propagation, new plants come from a single parent, making this option false.
- Size: Option D claims they are always smaller in size. This is not accurate; the size of the plant can vary based on environmental factors and care rather than the method of propagation used.
Conclusion
In summary, the correct answer is option A. Plants produced by vegetative propagation grow faster and can flower and fruit earlier than those grown from seeds, making this method highly effective for certain horticultural practices.

Why Flowers Are Colorful and Fragrant
Flowers have evolved to be colorful and fragrant primarily to attract insects, which play a crucial role in their reproduction.
Attraction of Pollinators
- The bright colors of flowers serve as visual cues to pollinators like bees, butterflies, and hummingbirds.
- Different colors attract different types of insects. For example, bees are drawn to blue and yellow hues, while butterflies prefer red and orange shades.
Fragrance and Scent
- Flowers emit pleasant fragrances that are appealing to insects.
- Scents can signal the presence of nectar, guiding pollinators directly to the flower.
Role in Reproduction
- When insects visit flowers to collect nectar, they inadvertently pick up pollen from the flower's anthers.
- As they move to other flowers, they transfer this pollen, facilitating fertilization and the production of seeds.
Co-evolution with Insects
- Over time, many flowers have developed specific traits that cater to their preferred pollinators.
- This co-evolution ensures that both the flowers and the insects benefit: flowers gain pollination, while insects gain food resources.
In conclusion, the vibrant colors and delightful scents of flowers are not merely for aesthetic appeal; they are vital adaptations for attracting insects, ensuring successful pollination, and promoting the continuation of plant species.

Pollination is the process by which pollen is transferred from the male part of a flower (anther) to the female part (stigma). This is a crucial step in the sexual reproduction of flowering plants.

Vegetative propagation is a form of asexual reproduction in plants where new plants are produced from the vegetative parts such as roots, stems, and leaves. This method allows plants to reproduce without seeds, ensuring the survival and spread of the species.

Budding is a method of asexual reproduction where a new individual develops from a bud, which is a small projection on the parent organism. This bud eventually detaches and becomes an independent organism.