1.

INTRODUCTION TO SEXUAL REPRODUCTION IN FLOWERING

PLANTS

Sexual reproduction in flowering plants is a process in which two gametes, one male and one
female, combine to form a new organism. This reproductive process ensures genetic variation,
which is vital for the adaptability and survival of plant species. It involves multiple stages, from
the formation of gametes to the development of seeds and, ultimately, a new plant. The primary
goal of sexual reproduction is to produce offspring that are genetically diverse, increasing the
chances of survival in changing environmental conditions.

Key Components of Sexual Reproduction in Flowering Plants

Flower: The reproductive organ of the plant, which houses both male and female reproductive
parts.

Male Gamete: The sperm cell, produced in the anther of the stamen, which fuses with the
female gamete during fertilization.

Female Gamete: The egg cell, found in the ovule inside the ovary of the pistil, which combines
with the male gamete to form the zygote.

Stages of Sexual Reproduction in Flowering Plants

1. Pollination: The transfer of pollen from the male reproductive organs (anther) to the female
reproductive organs (stigma). Pollination can be facilitated by various agents such as wind,
water, or animals.

2. Fertilization: The process where the male gamete (sperm) fuses with the female gamete
(egg), resulting in the formation of a zygote.

3. Seed Formation: The fertilized egg develops into a seed, which contains the embryo and
stored nutrients for future growth.

4. Dispersal and Germination: The mature seed is dispersed, and under favorable conditions, it
germinates, giving rise to a new plant.
Significance of Sexual Reproduction

Sexual reproduction provides genetic diversity, which helps plants adapt to environmental
changes and resist diseases. It is also crucial for the continuation of plant species, ensuring that
new generations are produced. Moreover, the variety of offspring produced through sexual
reproduction contributes to the ecological balance and biodiversity.

2. POLLINATION EFFICIENCY
Pollination efficiency refers to the ability of a pollination event to result in successful fertilization
and seed production. It is influenced by several factors, including the type of pollination, the
effectiveness of pollinators, and environmental conditions. The efficiency of pollination directly
impacts the reproductive success of flowering plants and their ability to produce seeds and
fruits.

Factors Affecting Pollination Efficiency

1. Pollinator Activity: The behavior and activity level of pollinators, such as bees, butterflies, and
birds, significantly influence the success of pollination. Pollinators that visit many flowers and
transfer pollen effectively increase pollination efficiency.

2. Flower Characteristics: The structure, size, and color of flowers can attract specific
pollinators. Flowers with bright colors and pleasant scents often attract more pollinators,
increasing the chances of successful pollination.

3. Timing of Pollination: The timing of flowering and pollinator activity is crucial. Pollination
efficiency is highest when flowers are open and pollinators are active. Seasonal changes and
temperature fluctuations can affect this timing.

4. Environmental Conditions: Weather conditions, such as wind, rain, and temperature, can
impact pollination efficiency. For instance, heavy rain or strong winds may prevent pollinators
from reaching flowers, reducing pollination success.

Types of Pollination and Their Efficiency

1. Self-Pollination: In self-pollination, pollen from the same flower or another flower on the same
plant fertilizes the ovule. Although it guarantees fertilization, it results in less genetic variation.
This is a less efficient form of pollination in terms of genetic diversity.

2. Cross-Pollination: Cross-pollination occurs when pollen from one plant fertilizes the ovule of
another plant. This form of pollination is generally more efficient as it promotes genetic diversity,
which helps the plant population adapt to changing environments.

3. Artificial Pollination: In some cases, human intervention is used to assist in pollination, such
as in agricultural practices. This can increase pollination efficiency, especially when natural
pollinators are scarce or ineffective.

Significance of Pollination Efficiency

Efficient pollination leads to successful fertilization, resulting in higher seed production and
healthy fruit development. It is essential for the growth of crop plants, the conservation of
biodiversity, and the production of seeds for new generations of plants.

3. TYPES OF POLLINATION
Pollination is the transfer of pollen from the male reproductive organ (anther) to the female
reproductive organ (stigma). There are two main types of pollination: self-pollination and cross-
pollination.

1. Self-Pollination

Self-pollination occurs when pollen from the same flower or from another flower on the same
plant fertilizes the ovule. This type of pollination does not require external pollinators, making it a
more straightforward process.

Advantages of Self-Pollination:

It ensures the plant produces seeds even in the absence of pollinators.

It is energy-efficient, as the plant does not rely on external factors like wind or animals for pollen
transfer.

It helps maintain the genetic traits of the plant species.

Disadvantages of Self-Pollination:

There is less genetic diversity because the offspring are genetically similar to the parent plant.

It limits adaptability to environmental changes and may increase the vulnerability of the
population to diseases.

2. Cross-Pollination

Cross-pollination is the transfer of pollen from one flower to the stigma of a different flower,
often from another plant. This process relies on external pollinators such as insects, birds, wind,
or water.

Advantages of Cross-Pollination:

It promotes genetic diversity, which helps plants adapt to changing environmental conditions.

It results in healthier and more vigorous offspring with better resistance to diseases.

Disadvantages of Cross-Pollination:

It requires the presence of suitable pollinators, which may not always be available.

It is dependent on external environmental factors like wind or the activity of animals.

3. Artificial Pollination

Artificial pollination is a human-mediated process used in agriculture and horticulture, where

pollen is manually transferred from one flower to another. It is commonly used for the production
of hybrid plants and in cases where natural pollination is insufficient.

Advantages of Artificial Pollination:

It ensures controlled cross-pollination, resulting in specific hybrid varieties.

It is used to increase the yield of crops in areas where natural pollination is inadequate.
Disadvantages of Artificial Pollination:

It is labor-intensive and costly.

It may reduce genetic diversity if overused.

4. POLLINATION MECHANISMS
Pollination mechanisms are the various ways in which pollen is transferred to facilitate
fertilization in flowering plants. These mechanisms can be biotic (involving living organisms) or
abiotic (involving non-living factors like wind or water).

1. Biotic Pollination

Biotic pollination involves living organisms such as insects, birds, bats, and other animals.
These organisms transfer pollen while they collect nectar or pollen for food.

Insect Pollination: The most common form of biotic pollination, where insects like bees,
butterflies, and beetles visit flowers to collect nectar. As they move from flower to flower, they
carry pollen, helping in fertilization.

Bird Pollination: Birds like hummingbirds transfer pollen from one flower to another. These birds
are attracted to brightly colored flowers, which they feed on for nectar.

Bat Pollination: Bats, particularly in tropical regions, pollinate flowers that are open at night and
produce strong scents and large quantities of nectar.

2. Abiotic Pollination

Abiotic pollination occurs through non-living agents, such as wind and water, which transport
pollen to the stigma.

Wind Pollination (Anemophily): Many plants, such as grasses and trees, rely on wind to transfer
pollen. Wind-pollinated flowers usually have light, dry pollen that is easily carried by air currents.

Water Pollination (Hydrophily): Water pollination occurs in aquatic plants. Pollen is carried by
water currents to fertilize flowers.
 5. PRE-FERTILIZATION EVENTS
Pre-fertilization events in flowering plants are the processes that prepare the gametes for
fertilization. These events occur before the actual fusion of male and female gametes, ensuring
that the plant is ready for reproduction.

1. Gametogenesis

Gametogenesis is the process by which male and female gametes are produced. In plants, this
occurs in the anther (male) and the ovule (female).

Male Gametogenesis: In the anther, diploid cells undergo meiosis to form haploid pollen grains.
Each pollen grain contains two sperm cells, one of which will fertilize the egg.

Female Gametogenesis: In the ovule, a diploid cell undergoes meiosis to form a haploid egg
cell. The ovule also contains other cells that will form the embryo sac.

2. Pollination

Pollination is the transfer of pollen from the male reproductive organ (anther) to the female
reproductive organ (stigma). It is a crucial event in the pre-fertilization process, as it brings the
male and female gametes close together for fertilization.

3. Pollen Tube Formation

After pollination, the pollen grain germinates on the stigma, forming a pollen tube. The pollen
tube grows down the style and into the ovary, where it will deliver the sperm cells to the ovule.

4. Maturation of Ovule

Before fertilization, the ovule must be mature. This involves the growth and development of the
egg cell and the surrounding tissues, preparing it to receive the male gamate.

6. FERTILIZATION IN FLOWERING PLANTS

Fertilization is the process in which the male gamete (sperm) fuses with the female gamete
(egg) to form a zygote. This process leads to the development of seeds and ensures the
continuation of the plant species. Fertilization in flowering plants involves several steps after
pollination, including the growth of the pollen tube and the fusion of gametes.
1. Pollen Tube Growth

Once the pollen grain reaches the stigma, it absorbs moisture and begins to germinate, forming
a pollen tube. The pollen tube travels down the style, guided by chemical signals released by
the ovule. This tube provides a path for the sperm cells to reach the ovule for fertilization.

2. Sperm Cell Movement

As the pollen tube grows, it moves through the style towards the ovary, carrying two sperm
cells. When the pollen tube reaches the ovule, it penetrates through the micropyle, a small
opening in the ovule, to release the sperm cells into the embryo sac.

3. Double Fertilization

In flowering plants, a unique event called double fertilization occurs. This involves two fusions:

Fusion of one sperm cell with the egg cell: This forms the zygote, which will eventually develop
into the embryo.

Fusion of the second sperm cell with the two polar nuclei in the central cell: This forms the
triploid endosperm, which provides nourishment to the developing embryo.

4. Formation of Zygote and Endosperm

Zygote: The fertilized egg cell, or zygote, develops into the embryo, which consists of the
plumule (shoot), radicle (root), and cotyledons (seed leaves).

Endosperm: The endosperm nourishes the developing embryo, supplying it with essential
nutrients for growth. In some plants, the endosperm is absorbed by the embryo during seed
development.

5. Fertilization Outcome

Fertilization results in the formation of a seed. The zygote develops into an embryo, the ovule
becomes a seed, and the ovary transforms into a fruit. The fertilized ovule undergoes changes
to form a mature seed, ready for dispersal.

7. POST-FERTILIZATION EVENTS
Post-fertilization events refer to the processes that occur after fertilization, leading to the
development of seeds and fruits. These events ensure that the fertilized ovule becomes a viable
seed capable of germination. The key steps include the formation of seeds, the development of
fruit, and the maturation of the seed.

1. Seed Development

After fertilization, the fertilized ovule develops into a seed. The zygote divides and forms the
embryo, while the surrounding ovule tissues transform into seed structures.

Embryo Development: The zygote develops into an embryo, consisting of a radicle (which
becomes the root), a plumule (which becomes the shoot), and cotyledons (seed leaves that
store nutrients).

Endosperm Development: The fertilized central cell, which contains the triploid endosperm,
nourishes the developing embryo, providing it with essential nutrients for growth.

Seed Coat Formation: The outer layers of the ovule harden to form the seed coat, which
protects the embryo and prevents desiccation.

2. Fruit Development

The ovary surrounding the fertilized ovule transforms into a fruit after fertilization. The fruit
protects the developing seeds and aids in their dispersal.

Formation of Fruit: The ovary wall thickens and becomes fleshy or dry, depending on the type of
fruit. This process is called maturation.

Types of Fruit: Fruits can be categorized into fleshy fruits (like apples, berries, and mangoes)
and dry fruits (like nuts and grains), based on their structure.

Function of Fruit: The fruit serves as a protective cover for the seeds and aids in their dispersal
by attracting animals or through mechanisms like wind or water.

3. Seed Maturation

As the seed develops, it undergoes a maturation process where it becomes dormant and gains
the ability to survive until conditions are right for germination.

Dormancy: Most seeds enter a state of dormancy during maturation, which prevents them from
germinating until environmental conditions (like water, temperature, and light) are suitable.
Nutrient Storage: The seed stores nutrients in the form of starch, proteins, and oils within the
cotyledons and endosperm, which provide energy for the embryo during germination.

4. Seed Dispersal

Once the seed matures, it is dispersed away from the parent plant to reduce competition and
increase the chances of survival.

Methods of Seed Dispersal: Seeds can be dispersed through various means, including wind
(anemochory), animals (zoochory), water (hydrochory), and mechanical forces (autochtory).

Role of Fruit in Dispersal: Many fruits attract animals that eat the fruit and later excrete the
seeds in different locations, facilitating seed dispersal.

8. SEED FORMATION AND DEVELOPMENT

Seed formation and development begin after fertilization and continue until the seed reaches
maturity. The seed is a vital structure for plant reproduction, as it contains the embryo and the
necessary nutrients to support the growth of a new plant. Seed formation involves several
stages, including the development of the seed coat, embryo, and endosperm.

1. Embryo Development

After fertilization, the zygote develops into an embryo. The embryo consists of several parts:

Radicle: The embryonic root that will grow into the primary root of the plant.

Plumule: The embryonic shoot that will develop into the stem and leaves.

Cotyledons: Seed leaves that provide nutrients to the developing embryo before it is able to
perform photosynthesis.

The development of the embryo is crucial for the formation of a healthy seed capable of
germinating and producing a new plant.

2. Endosperm Formation

In double fertilization, one sperm cell fuses with the egg to form the zygote, while the second
sperm cell fuses with the polar nuclei in the ovule to form the triploid endosperm. The
endosperm is a tissue that nourishes the developing embryo and provides essential nutrients
like starch, proteins, and lipids.

Function of Endosperm: The endosperm acts as a food reserve for the embryo during seed
development. It helps sustain the seed until it germinates and begins photosynthesis.

3. Seed Coat Formation

The outer layers of the ovule harden to form the seed coat. The seed coat protects the embryo
from physical damage, dehydration, and pathogens. The seed coat also regulates water
absorption during germination.

Types of Seed Coats: Seed coats can be hard and impermeable or soft and permeable,
depending on the plant species. The coat also helps in seed dispersal by facilitating different
mechanisms, such as attachment to animal fur or being buoyant in water.

4. Maturation of Seed

As the seed develops, it undergoes a process of maturation. During this stage, the seed
becomes dormant, which helps it survive adverse environmental conditions.

Dormancy: Seed dormancy is a period of rest during which the seed does not germinate, even
under favorable conditions. Dormancy ensures that seeds do not sprout until the environmental
conditions are suitable for growth.

Desiccation: As the seed matures, water content decreases, and the seed enters a dry state.
This reduces metabolic activity and preserves the seed until it can germinate.

5. Seed Storage

During the development of the seed, nutrients are stored in the form of starch, protein, and fats.
These stored nutrients will be used by the embryo when the seed begins to germinate.

9. SEED DISPERSAL
Seed dispersal is the process by which seeds are spread away from the parent plant to
reduce competition for resources and increase the chances of survival. This helps to colonize
new areas and ensures the continuation of the plant species. There are several methods by
which seeds can be dispersed.
1. Methods of Seed Dispersal

Wind Dispersal (Anemochory): Many plants rely on wind to carry their seeds to new locations.
Wind-dispersed seeds are typically small, lightweight, and equipped with structures like wings,
hairs, or parachutes to aid in their travel.

Examples: Dandelion, maple trees, and grasses.

Animal Dispersal (Zoochory): Seeds can be dispersed by animals in two ways:

Ingestion: Animals, such as birds and mammals, consume fruits and then excrete the seeds in
different locations. The seeds pass through the digestive system and are often deposited with a
natural fertilizer.

Attachment: Some seeds have hooks or sticky surfaces that allow them to attach to the fur or
feathers of animals. These seeds are carried to new areas and eventually fall off.

Examples: Berries (eaten by birds) and burdock (seeds stick to fur).

Water Dispersal (Hydrochory): Some plants, especially aquatic plants, use water as a medium
for seed dispersal. Seeds are buoyant and can float on water currents, allowing them to travel
long distances to new areas.

Examples: Coconut (seeds float on ocean currents), water lilies.

Mechanical Dispersal (Autochory): In this method, seeds are dispersed by the plant itself. As the
seed matures, it can be ejected from the fruit by mechanical means, such as tension in the
fruit’s wall or the twisting of seed pods.

Examples: Pea plants (pods split open), touch-me-not (seeds are ejected when touched).

2. Importance of Seed Dispersal

Seed dispersal is essential for the survival and spread of plant species. It prevents
overcrowding, reduces competition for resources, and allows plants to colonize new habitats.
Dispersal mechanisms also help plants to adapt to changing environments and expand their
population.
Reduced Competition: By spreading seeds away from the parent plant, the young plants have
more access to light, water, and nutrients.

Colonization of New Areas: Dispersal helps plants to reach new habitats, increasing the chance
of species survival and adaptation.

Genetic Diversity: Dispersal mechanisms that promote cross-pollination can also help increase
genetic variation, enhancing the adaptability of plant species.

10. GERMINATION OF SEEDS

Seed germination is the process by which a seed develops into a new plant. It begins when the
seed absorbs water and ends when the seedling emerges. Germination is essential for the
continuation of plant life and occurs under specific environmental conditions.

1. Conditions Required for Germination

For seed germination to occur, the following conditions are essential:

Water: The seed must absorb water through a process called imbibition. Water activates
enzymes that start the metabolic processes needed for growth.

Temperature: Each species has a specific temperature range at which its seeds will germinate.
Most seeds require a temperature range between 20°C and 30°C.

Oxygen: Seeds need oxygen for respiration to provide the energy necessary for growth. Without
oxygen, seeds cannot undergo the biochemical processes required for germination.

Light: Some seeds require light to germinate, while others may germinate in the dark. Light-
sensitive seeds, such as those of certain weeds, use light to trigger the germination process.

2. Stages of Germination

Seed germination occurs in several stages:

1. Imbibition: The seed absorbs water from the environment, causing it to swell and activate its
metabolic processes.

2. Activation of Metabolism: After water absorption, stored nutrients in the seed’s endosperm or
cotyledons are broken down and used to fuel growth.
3. Radicle Emergence: The radicle, or embryonic root, is the first part to emerge. It anchors the
seed into the soil and begins to absorb water and nutrients.

4. Plumule Emergence: The plumule, or embryonic shoot, grows upwards towards the surface.
It eventually breaks through the soil and begins to form the stem and leaves.

5. Seedling Development: Once the shoot has emerged, the cotyledons provide initial nutrients
until the true leaves form and the plant can begin photosynthesis.

3. Types of Germination

There are two main types of germination:

Epigeal Germination: In this type, the cotyledons are pushed above the soil surface as the
seedling grows. This type is common in dicots, such as beans.

Hypogeal Germination: In hypogeal germination, the cotyledons remain below the soil surface,
and the first true leaves appear above ground. This type is common in monocots, such as peas.

4. Factors Affecting Germination

Several factors can influence the success of seed germination:

Seed Quality: Fresh, viable seeds are more likely to germinate successfully. Old or damaged
seeds may fail to germinate.

Soil Type: Well-drained, nutrient-rich soil supports successful germination.

Moisture Levels: The soil must have the right amount of moisture. Too much water can lead to
waterlogging, while too little can cause the seed to dry out.

Seed Depth: Seeds need to be planted at an appropriate depth. If planted too deep, they may
not receive enough light, while if too shallow, they may dry out.

5. Importance of Germination
Germination is vital for the growth of new plants. It enables the plant to begin its life cycle, grow,
and eventually reproduce. Proper germination is necessary for the survival of plant species and
for the continuation of ecosystems.

Plant Reproduction: Without germination, plants would not be able to reproduce and produce
new generations.

Agricultural Importance: For crops, successful germination is critical for a healthy harvest.
Farmers rely on good germination rates for high-yielding crops.

Ecological Balance: Germination allows plants to colonize new areas and contribute to
biodiversity.

11. ROLE OF SEXUAL REPRODUCTION IN PLANT

DIVERSITY
Sexual reproduction in plants plays a crucial role in enhancing genetic diversity, which is
essential for the survival, adaptation, and evolution of plant species. This process not only leads
to the formation of new generations but also contributes to the resilience of plant populations in
changing environments.

1. Genetic Variation

Sexual reproduction involves the combination of genetic material from two parent plants (male
and female gametes), resulting in offspring with a unique genetic makeup. This genetic variation
is the foundation of plant diversity and is essential for the following reasons:

Increased Adaptability: Plants with diverse genetic traits are better equipped to adapt to
environmental stresses such as changes in climate, disease, pests, and competition.

Prevention of Inbreeding: Sexual reproduction reduces the chances of inbreeding, which can
lead to genetic defects and reduced fitness in plants. Cross-pollination ensures that genetic
material from different individuals is mixed, which enhances plant vigor.

New Traits: Each generation produced through sexual reproduction may exhibit new traits that
are beneficial for survival, such as improved disease resistance or tolerance to drought. These
new traits can contribute to the overall biodiversity of plant species.

2. Evolutionary Significance
Sexual reproduction is a key driver of evolutionary processes. It leads to genetic reshuffling,
which results in new genetic combinations and the potential for the development of new
species. This process plays a critical role in the evolution of plant diversity.

Natural Selection: Genetic diversity enables natural selection to act upon the population. Plants
with advantageous traits are more likely to survive, reproduce, and pass on their beneficial
genes to the next generation.

Speciation: Sexual reproduction, especially in combination with geographic isolation or

environmental pressures, can lead to speciation—the formation of new plant species. Over time,
populations of plants may evolve distinct characteristics, leading to the emergence of new
species adapted to specific niches.

3. Ecological Impact

The diversity generated through sexual reproduction has significant ecological benefits.
Different plant species play unique roles in ecosystems, contributing to the balance of
biodiversity and ecosystem functions.

Supporting Pollinators: A diverse range of plant species provides habitats and food sources for
various pollinators, such as bees, butterflies, and birds. This mutual relationship supports both
plant and animal biodiversity.

Enhancing Ecosystem Stability: Greater plant diversity helps stabilize ecosystems by improving
their resilience to disturbances such as natural disasters, pests, and diseases. Diverse plant
communities are more likely to maintain ecosystem services such as soil fertility, water
retention, and carbon sequestration.

4. Agricultural Importance

In agriculture, sexual reproduction is essential for the development of new crop varieties with
improved characteristics, such as higher yield, disease resistance, and drought tolerance. Crop
breeding programs use sexual reproduction to combine desirable traits from different plant
varieties, resulting in more diverse and robust crops that can meet the needs of a growing
global population.

Hybrid Vigor: The crossbreeding of different plant varieties often leads to hybrid vigor, where the
offspring exhibit superior qualities compared to the parent plants, such as increased resistance
to diseases and pests.
Crops with Increased Resilience: Through sexual reproduction and selective breeding, new crop
varieties can be developed that are more resilient to environmental challenges like climate
change, ensuring food security.

In summary, sexual reproduction is essential for generating genetic diversity in plants, which in
turn contributes to the survival, adaptation, and evolution of plant species. It plays a significant
role in the ecological balance, agricultural improvement, and the continued success of plant
populations in diverse environments. This process not only enhances the resilience of plants but
also supports the biodiversity that is critical for maintaining healthy ecosystems.

CONCLUSION
Sexual reproduction in flowering plants is a fundamental biological process that ensures the
continuation of species and promotes genetic diversity. It involves a series of intricate steps,
including pollination, fertilization, and post-fertilization events, culminating in the formation of
seeds and fruit. Through sexual reproduction, plants can adapt to their environment, evolve over
generations, and contribute to the overall balance and stability of ecosystems.

Pollination, an essential step in sexual reproduction, can occur through various mechanisms
such as wind, insects, birds, and animals, each ensuring that plants can reproduce efficiently.
The development of seeds, and their subsequent dispersal, further promotes genetic diversity
by allowing plants to spread to new areas and avoid competition with parent plants.

The role of sexual reproduction in enhancing plant diversity cannot be overstated. By facilitating
the exchange of genetic material, sexual reproduction allows for the emergence of new traits,
which increase a plant's ability to survive in changing conditions. This genetic diversity plays a
critical role in the adaptation of plants to evolving environments, as well as in the evolution of
new species over time.

Moreover, sexual reproduction’s role in agriculture is indispensable. It allows for the

development of crop varieties that are more resilient to pests, diseases, and adverse
environmental conditions, ensuring food security. Through selective breeding and hybridization,
sexual reproduction continues to benefit agriculture, contributing to global food production and
biodiversity conservation.

In conclusion, sexual reproduction in flowering plants is not only vital for the plants themselves
but also for the ecosystems they inhabit and the agricultural systems that depend on them. Its
importance extends beyond plant reproduction, influencing biodiversity, ecological stability, and
human livelihoods.
FIGURES AND DIAGRAMS

1. INTRODUCTION TO SEXUAL REPRODUCTION IN FLOWERING

PLANTS

2. POLLINATION EFFICIENCY

3. TYPES OF POLLINATION
4. POLLINATION MECHANISM

5.PRE FERTILIZATION EVENTS

6.FERTILIZATION IN FLOWERING PLANTS

7.POST FERTILIZATION EVENTS

8.SEED FORMATION AND DEVELOPMENT

9.TYPES OF SEEDS AND DISPERSAL

10.SEED GERMINATION

11.ROLE OF SEXUALY REPRODUTION IN PLANT DIVERSITY

12.CONCLUSION