All questions of Plant Kingdom for BPSC (Bihar) Exam

1. fruits is made up of ovary
2. seed is made up of ovule
3. wood is made up of stem
4. starch is present in leaf
so the correct answer is B.

Range is not a measure of central tendency at all. It is an absolute measure of Dispersion that is explained by the difference between the maximum and the minimum values in a series. Now, a comparison between the stability amongst Mean, Median and Mode depends on the nature of the distribution that you're working with. Let's say your data has a lot of outliers, in such a case mean will not serve the purpose well as a measure of CT, Median would be more appropriate. Remember that Mean is affected by extreme values while Median is not. Mode is more appropriate when you're more concerned about the frequency of occurences. For example if you wanted to know what size of shoes should a shoe seller keep more in stock compared to the other sizes.

Photoperiodism
Photoperiodism is the term used to describe the response of plants to the timing of light and darkness. This phenomenon plays a crucial role in various plant processes such as flowering, seed germination, and dormancy.

Key Points
- Plants have evolved the ability to sense and respond to changes in the length of day and night.
- Photoperiodism helps plants to synchronize their growth and development with seasonal changes in the environment.
- There are three main categories of photoperiodism: short-day plants, long-day plants, and day-neutral plants.
- Short-day plants require a period of darkness longer than a critical length to initiate flowering, while long-day plants require a period of darkness shorter than a critical length.
- Day-neutral plants are not influenced by day length and will flower regardless of the photoperiod.
In conclusion, photoperiodism is a crucial mechanism that allows plants to adapt to changing environmental conditions and ensure optimal growth and reproduction. Understanding this phenomenon is essential for agricultural practices, as it can help in determining the most suitable planting times and optimizing crop yields.

Gymnosperms are a group of plants that produce naked seeds (seeds not enclosed in a fruit) and have well-developed vascular tissues. Gymnosperms are often considered a "fossil group" because they have ancient origins and include plants like conifers that have been around for a long time. The term "gymnosperm" means "naked seed," referring to the fact that the seeds are exposed on the surface of cone scales or other structures.

Flower: The Reproductive Part of a Plant

The metamorphosed part of the shoot that is meant for plant reproduction is the flower. Flowers are the reproductive structures of angiosperms, which are a group of plants that produce seeds enclosed within a fruit. They are the most diverse and abundant group of plants on Earth, and their flowers play a crucial role in their reproductive process.

Structure and Function of a Flower

A flower is composed of several different parts, each with its specific function in the reproductive process. These parts include:

1. Petals: Petals are the colorful, leaf-like structures that surround the reproductive organs of the flower. They are responsible for attracting pollinators, such as insects or birds, to facilitate pollination.

2. Sepals: Sepals are the small, usually green, leaf-like structures that protect the developing flower bud. They are located at the base of the flower and enclose it before it blooms.

3. Stamens: Stamens are the male reproductive organs of the flower. They consist of two main parts: the filament and the anther. The filament is a thin stalk that supports the anther, which contains pollen grains. Pollen is the male gamete that is necessary for fertilization.

4. Carpels: Carpels are the female reproductive organs of the flower. They are composed of three main parts: the stigma, style, and ovary. The stigma is the sticky structure at the top of the carpel that receives pollen. The style is a long tube-like structure that connects the stigma to the ovary. The ovary contains the ovules, which are the female gametes that develop into seeds after fertilization.

5. Receptacle: The receptacle is the base of the flower where all the other parts are attached. It provides support and protection for the reproductive organs.

Plant Reproduction

The flower plays a crucial role in plant reproduction by facilitating the process of pollination and fertilization. Pollination occurs when pollen grains are transferred from the anther of a stamen to the stigma of a carpel. This can happen through various means, including wind, water, or the assistance of pollinators.

Once the pollen grain lands on the stigma, it germinates and grows a pollen tube down through the style, eventually reaching the ovary. The male gametes inside the pollen grain travel down the pollen tube and fertilize the ovules inside the ovary. This process leads to the formation of seeds.

After fertilization, the ovary develops into a fruit, which protects the seeds and aids in their dispersal. The seeds can then germinate and grow into new plants, continuing the life cycle.

In conclusion, the metamorphosed part of the shoot that is meant for plant reproduction is the flower. Flowers are the reproductive structures of angiosperms and consist of various parts, including petals, sepals, stamens, carpels, and the receptacle. The flower plays a crucial role in facilitating pollination, fertilization, and the formation of seeds, which are essential for plant reproduction and the continuation of the plant life cycle.

The Indian Pipe Plant or Monotropa

The Indian Pipe Plant, also known as Monotropa, belongs to the group of saprophytes. Saprophytes are plants that obtain their nutrients by decomposing dead organic matter. Let's understand why Monotropa is classified as a saprophyte.

Saprophytes

Saprophytes are unique plants that do not have chlorophyll and therefore cannot perform photosynthesis. Instead, they rely on obtaining nutrients from decaying organic matter, such as dead plants, animal remains, or fecal matter. These plants play a crucial role in the ecosystem by breaking down organic material and recycling nutrients.

Characteristics of Monotropa

Monotropa, commonly known as the Indian Pipe Plant, is a fascinating parasitic plant that belongs to the saprophyte group. Some key characteristics of Monotropa are as follows:

1. Lack of chlorophyll: Monotropa does not possess chlorophyll, which is responsible for the green color in plants. This absence of chlorophyll makes it unable to carry out photosynthesis and produce its own food.

2. Dependence on mycorrhizal fungi: Monotropa forms a symbiotic relationship with mycorrhizal fungi. These fungi are present in the soil and help in absorbing nutrients from decaying organic matter. The fungi provide essential nutrients to Monotropa, while the plant provides carbohydrates to the fungi.

3. White or pale coloration: Due to the absence of chlorophyll, Monotropa appears pale or white in color. It has a waxy texture, giving it a ghostly appearance.

4. Habitat and distribution: Monotropa is commonly found in moist, shady areas of forests. It grows on the forest floor, often in association with certain tree species. It is found in various regions of the world, including North America, Europe, and Asia.

Conclusion

In conclusion, the Indian Pipe Plant or Monotropa is classified as a saprophyte. It lacks chlorophyll and relies on mycorrhizal fungi to obtain nutrients from decaying organic matter. Understanding the classification of plants helps us appreciate the diversity of the plant kingdom and their unique adaptations for survival.

Micropropagation by plant tissue culture has the advantage of producing virus-free clones by raising callus from shoot apex. This technique is useful for obtaining disease-free plants.

Flowers typically have four whorls: sepals, petals, stamens, and carpels. These whorls together make up the floral structure and are involved in the reproductive process.

Primary Function of Roots in Plants: Anchoring the Plant and Absorbing Water and Minerals

Roots are an essential part of the plant structure and play a crucial role in its overall growth and survival. While they may not be as visible as leaves or flowers, roots serve several important functions that are vital for the plant's well-being. The primary function of roots in plants is to anchor the plant securely in the ground and to absorb water and minerals from the soil. Let's delve into the details of these functions:

1. Anchoring the Plant:
Roots provide stability and support to the plant by anchoring it firmly in the ground. This is particularly important for tall and large plants that need a strong foundation to withstand winds, heavy rainfall, and other environmental factors. The root system forms an underground network that helps to keep the plant upright and prevents it from toppling over. Without proper anchorage, plants would be vulnerable to physical damage and would struggle to grow and survive.

2. Absorbing Water and Minerals:
One of the most crucial roles of roots is to absorb water and essential minerals from the soil. The root system consists of numerous tiny root hairs that greatly increase the surface area for absorption. These root hairs have a thin cell wall, which allows for efficient uptake of water and minerals through a process called osmosis. The root hairs also have a close association with mycorrhizal fungi, which further enhance nutrient absorption.

Water is vital for the plant's survival as it is involved in various physiological processes such as photosynthesis, nutrient transportation, and maintaining turgidity. Roots absorb water from the soil and transport it upwards to the stems, leaves, and other parts of the plant through the xylem tissue.

Similarly, minerals such as nitrogen, phosphorus, potassium, and various micronutrients are essential for the plant's growth and development. Roots absorb these minerals from the soil and transport them to the rest of the plant through the phloem tissue. These minerals are used in various biochemical reactions and are crucial for the synthesis of proteins, enzymes, and other important compounds.

In summary, the primary function of roots in plants is to anchor the plant securely in the ground and to absorb water and minerals from the soil. Without a well-developed root system, plants would be unable to survive and grow efficiently. Therefore, roots are fundamental to the overall health and productivity of plants.

Transpiration
Transpiration is the process by which excess water in the form of vapor is lost through the aerial parts of a plant, mainly through the stomata on the leaves. This process is crucial for plants as it helps in cooling the plant, transporting nutrients and minerals, and maintaining turgidity in the cells.
Significance of Transpiration
- **Cooling mechanism**: Transpiration helps in cooling the plant by releasing excess heat during the process of water vaporization.
- **Nutrient transport**: Water and minerals absorbed by the roots are transported to different parts of the plant through the process of transpiration.
- **Maintaining turgidity**: Transpiration helps in maintaining turgidity in the plant cells, which is essential for plant structure and growth.
Mechanism of Transpiration
- **Stomata**: Tiny openings on the surface of leaves through which water vapor escapes.
- **Guard cells**: Surround the stomata and regulate their opening and closing to control transpiration.
- **Root pressure and cohesion-tension theory**: Water is absorbed by roots and transported to leaves, where it evaporates through stomata due to differences in water potential.
Factors affecting Transpiration
- **Environmental conditions**: Temperature, humidity, wind speed, and light intensity influence the rate of transpiration.
- **Plant factors**: Number and distribution of stomata, leaf surface area, and plant species affect transpiration rates.
Conclusion
Transpiration is a vital process for plants as it helps in maintaining water balance, nutrient transport, and overall plant health. Understanding the mechanisms and factors influencing transpiration is crucial for effective plant growth and development.

The primary advantage of transpiration in plants is the removal of excess water.
- Regulation of water balance: Transpiration helps plants maintain a proper water balance by allowing them to release excess water. This process is crucial for preventing waterlogging and ensuring that the plant does not become overly hydrated.
- Cooling mechanism: Transpiration also serves as a cooling mechanism for plants. As water evaporates from the leaves, it takes away heat energy, which helps regulate the plant's temperature and prevent overheating.
- Nutrient uptake: Transpiration creates a negative pressure in the plant, which helps in the uptake of water and essential nutrients from the soil. This process is essential for the plant's growth and overall health.
- Transport of minerals: Transpiration facilitates the movement of minerals and nutrients through the plant's vascular system. As water evaporates from the leaves, it creates a pull that helps transport minerals from the roots to other parts of the plant.
In conclusion, transpiration plays a vital role in the overall health and functioning of plants by regulating water balance, facilitating nutrient uptake, and serving as a cooling mechanism. It is a crucial process that helps plants thrive in their environment.

The uppermost part of the gynoecium is called the stigma, and its primary function is to trap pollen for fertilization.

Main difference between bacteria and viruses:

Reproduction:
- Bacteria can reproduce on their own through a process called binary fission. They can replicate their DNA and divide into two daughter cells.
- On the other hand, viruses cannot reproduce independently. They require a host cell to replicate themselves. Viruses inject their genetic material into a host cell and hijack the cellular machinery to produce more virus particles.

Structure:
- Bacteria are prokaryotic organisms, which means they do not have a nucleus or other membrane-bound organelles. They have a relatively simple cellular structure with a cell wall, cell membrane, and genetic material floating freely in the cytoplasm.
- Viruses, on the other hand, are much smaller and simpler than bacteria. They are not considered living organisms as they lack cellular structure. Viruses consist of genetic material (DNA or RNA) surrounded by a protein coat called a capsid. Some viruses may also have an outer envelope derived from the host cell.

Size:
- Bacteria are generally larger than viruses. Bacterial cells can vary in size, ranging from a few micrometers to hundreds of micrometers in length.
- In contrast, viruses are much smaller, usually ranging from 20 to 300 nanometers in size. They are significantly smaller than most bacterial cells and can only be seen under an electron microscope.

Impact on Health:
- Bacteria can have both positive and negative impacts on health. While some bacteria are harmful and cause diseases, many bacteria are beneficial and play essential roles in various natural processes and even in our bodies, such as aiding digestion and synthesizing vitamins.
- Viruses, on the other hand, are generally associated with causing diseases. They can infect various organisms, including humans, animals, and plants, and cause illnesses ranging from common colds to more severe conditions like influenza, HIV, and COVID-19.

Conclusion:
The main difference between bacteria and viruses lies in their ability to reproduce. Bacteria can reproduce independently through binary fission, while viruses require a host cell to replicate. Additionally, bacteria are larger and have a more complex cellular structure compared to viruses. While bacteria can have both positive and negative impacts on health, viruses are generally associated with causing diseases.

B. Protecting against herbivores

Stipules are small, leaf-like structures that are typically found at the base of a leaf where it attaches to the stem. They can vary in size, shape, and color, depending on the plant species. Stipules serve several functions in plants, including protection against herbivores.

1. Protection against herbivores:
Stipules can have various adaptations that help protect the plant from being eaten by herbivores. Some stipules are modified into sharp spines or thorns, which can deter animals from feeding on the plant. These structures act as physical barriers, making it more difficult for herbivores to access the leaves or other parts of the plant. The presence of stipules can also signal the presence of chemical defenses in the plant, such as toxins or unpleasant tastes, further deterring herbivores.

2. Aiding in photosynthesis:
While stipules primarily serve a protective function, some stipules may also contribute to photosynthesis. Stipules that are green and contain chlorophyll can carry out photosynthesis, helping the plant produce energy from sunlight. However, this function is not as common or significant as protection against herbivores.

3. Attaching the leaf to the stem:
Stipules play a role in attaching the leaf to the stem. They provide support and stability, preventing the leaf from falling off or being easily detached from the plant. Stipules can act as a bridge between the leaf and the stem, ensuring a secure connection.

4. Supporting water conservation:
In some plants, stipules may have adaptations that aid in water conservation. For example, certain stipules can be modified into small, scale-like structures that cover the leaf bud during dormancy or periods of water scarcity. These modified stipules help reduce water loss through evaporation and protect the delicate leaf bud from desiccation.

In conclusion, while stipules can have multiple functions, the primary function of stipules in a plant leaf is to protect against herbivores. They can also aid in photosynthesis, attach the leaf to the stem, and support water conservation in certain plant species.

The primary function of the ovary in the gynoecium of a flower is to develop into a fruit after fertilization. The ovary contains ovules, which, when fertilized, turn into seeds, and the ovary itself matures into a fruit.

The complete oxidation of glucose in aerobic respiration results in the production of carbon dioxide and water, along with the release of energy in the form of ATP.

Budding is a method of artificial vegetative propagation that involves the use of an individual bud with adjacent bark from one plant and inserting it into a cut made in the stock of another plant.

Thallophytes, which include algae, fungi, bacteria, slime molds, and some bryophytes, are characterized by the absence of well-developed vascular tissues. Vascular tissues like xylem and phloem, which are responsible for transporting water and nutrients in higher plants, are generally absent or poorly developed in thallophytes. This is one of the distinguishing features of thallophytes and sets them apart from higher plants.

Sclerenchyma tissue is found in the hard parts of the plant body and serves to provide mechanical strength against various environmental stresses, such as wind. It adds rigidity to plant structures.