How Do Organisms Reproduce? - Class 10 Science (Compulsory Test) - Class 10 MCQ

Vegetative reproduction is a type of asexual reproduction in which new plants are formed from the vegetative parts like, tubers, runners, suckers, rhizomes etc. Adventitious leaf buds are produced on the notches of Bryophyllum leaf. These adventitious buds can be used for vegetative propagation. The buds can develop into individual plants when favourable conditions are provided. 

Thus, the correct answer is option b. 

Explanation:
The group of petals is not referred to as any of the given options. The correct answer is D. None of these.
Here is an explanation of each option:
A. Sepals:
- Sepals are the outermost part of a flower, usually green in color.
- Sepals protect the flower bud before it blooms.
- They are typically leaf-like structures.
B. Calyx:
- The calyx is the outermost whorl of a flower, composed of sepals.
- It protects the inner parts of the flower during bud stage.
- Sepals collectively form the calyx.
C. Root:
- The root is a part of the plant that anchors it in the soil and absorbs water and nutrients.
- It is not related to the group of petals in a flower.
D. None of these:
- This option is the correct answer because none of the given options correctly describe the group of petals.
To summarize, the group of petals in a flower is not called sepals, calyx, or root. The correct answer is D. None of these.

The portion of the plant that is grafted is called the scion.
Explanation:
During grafting, a portion of one plant is joined with another plant in order to combine their desirable traits. The portion of the plant that is taken from one plant and grafted onto another is called the scion.
- Grafting is a horticultural technique used to propagate plants, improve plant vigor, and change the characteristics of a plant.
- The scion is usually a small piece of a stem, bud, or shoot that contains the desired traits such as specific flower color, fruit size, or disease resistance.
- The scion is carefully selected and cut from the desired plant and then attached to the stock or rootstock of another plant.
- The stock, also known as the rootstock, is the lower portion of the plant onto which the scion is grafted.
- The stock provides the root system and often contributes disease resistance and other beneficial characteristics to the grafted plant.
- The scion and stock are joined together by making precise cuts and securing them with grafting tape or other grafting materials.
- Over time, the scion and stock will grow together, forming a strong union and allowing the scion to receive nutrients and water from the stock's root system.
In summary, the scion is the portion of the plant that is grafted onto another plant during the process of grafting. It carries the desired traits and is joined with the stock to create a new plant with combined characteristics.

Method of producing new plants in roses:

• Tissue culture: This method involves the growth of new plants from small tissue samples taken from the parent plant. However, tissue culture is not commonly used in rose propagation.


• Cutting: The most commonly used method for producing new rose plants is through cuttings.


• Layering: Layering is another method used in rose propagation, where a stem is bent and partially buried in the ground to encourage rooting. However, it is not as commonly used as cutting.


• None of these: This option is incorrect as cutting is indeed the commonly used method for producing new rose plants.

Therefore, the correct answer is B: cutting.

The Production of Pollen Grains
Anther:
- Pollen grains are produced by the anther, which is a part of the male reproductive organ of flowering plants called the stamen.
- The anther contains microsporangia, which are structures that produce pollen grains through a process called microsporogenesis.
Microsporogenesis:
- Microsporogenesis is the process by which pollen grains are produced within the anther.
- It involves the division and differentiation of cells within the microsporangia.
- The cells undergo meiosis, resulting in the formation of haploid microspores.
- Each microspore then undergoes further divisions to develop into a mature pollen grain.
Pollen Grain Structure:
- A pollen grain is a male gametophyte, containing the male reproductive cells of the plant.
- It is surrounded by a tough outer layer called the exine, which protects the pollen grain during its journey from the anther to the stigma.
- The exine is often decorated with various patterns and structures, which can be used for species identification.
Pollen Transfer and Pollination:
- After the pollen grains are produced in the anther, they are released into the environment.
- Pollen transfer can occur through various mechanisms, such as wind, water, or animal pollinators.
- When a pollen grain reaches the stigma of a flower, it can germinate and grow a pollen tube, allowing the male reproductive cells to reach the ovary and fertilize the female reproductive cells.
In conclusion, pollen grains are produced by the anther, a part of the male reproductive organ called the stamen. The anther undergoes the process of microsporogenesis, resulting in the formation of mature pollen grains. These pollen grains play a crucial role in plant reproduction as they are transferred to the stigma and facilitate fertilization.

Explanation:


Insect-pollinated flowers have certain characteristics that attract and facilitate pollination by insects. The correct answer to the question is option C: Flowers are conspicuous and scented, having nectar. Here is a detailed explanation of why this option is applicable to insect-pollinated flowers:
1. Flowers are conspicuous:
- Insect-pollinated flowers are usually large and brightly colored to attract insects.
- These flowers stand out in the environment, making them easy for insects to locate.
2. Flowers are scented:
- Insect-pollinated flowers often produce strong and pleasant scents.
- The scent acts as a signal to attract insects, as many insects have a well-developed sense of smell.
3. Flowers have nectar:
- Nectar is a sweet liquid produced by flowers to attract insects.
- Insect-pollinated flowers have nectar as a reward for insects that visit them.
- The nectar serves as a food source for insects, particularly bees and butterflies, which have long tongues to reach the nectar.
4. Importance of insects in pollination:
- Insects, such as bees, butterflies, and moths, play a crucial role in pollination.
- While visiting flowers for nectar, insects inadvertently transfer pollen from the male reproductive parts (anthers) to the female reproductive parts (stigma) of the flower, facilitating fertilization and seed production.
Conclusion:
Flowers that are conspicuous, scented, and have nectar are well-suited for insect pollination. These characteristics act as attractants and rewards for insects, ensuring the successful transfer of pollen and fertilization.

The group of sepals is called the calyx.
Explanation:
The calyx is a part of the flower that consists of a group of sepals. Sepals are the outermost whorl of floral organs that protect the developing flower bud. They are usually green in color and can be fused together or separate. The calyx plays a role in protecting the inner floral organs, especially during the bud stage.
Here is a detailed explanation of the options given:
A. Gynoecium:
- The gynoecium refers to the female reproductive organs of a flower, including the pistil(s). It consists of the stigma, style, and ovary.
B. Calyx:
- The calyx is the group of sepals that surround and protect the bud of a flower. It is usually green and can be fused or separate.
C. Corolla:
- The corolla refers to the group of petals in a flower. Petals are often colorful and serve to attract pollinators.
D. Androecium:
- The androecium refers to the male reproductive organs of a flower, including the stamens. It consists of the anther and filament.
In conclusion, the correct answer is B. The group of sepals is called the calyx.

Maize is cross pollinated by wind.

Maize, also known as corn, is a cereal crop that is primarily cross pollinated by wind. The male flowers of maize, called tassels, produce pollen grains that are released into the air. These pollen grains are then carried by the wind to the female flowers, known as silks, which are located on the ears of the plant.

Here is a detailed explanation of why maize is cross pollinated by wind:

1. Structure of the maize plant:
- Maize plants have separate male and female flowers. The male flowers are located at the top of the plant in the form of tassels, while the female flowers are found on the ears of the plant.
- The tassels produce anthers, which contain pollen grains, while the silks on the ears serve as the female reproductive organs.
2. Pollen release:
- Maize plants release large amounts of lightweight pollen grains into the air.
- The anthers on the tassels burst open, and the pollen grains are released. These pollen grains are small and powdery, allowing them to be easily carried by the wind.
3. Pollen transport:
- As the wind blows, it carries the pollen grains from the tassels to the silks on the ears of neighboring maize plants.
- The large number of pollen grains released increases the chances of successful pollination.
4. Pollination process:
- When the pollen grains land on the sticky stigmas of the silks, they germinate and grow down through the silk to reach the ovules.
- The fertilization of the ovules by the pollen grains leads to the development of kernels on the ears.
5. Advantages of wind pollination:
- Wind pollination allows maize plants to efficiently pollinate a large number of ears.
- It does not rely on external factors such as insects or rain, making it a reliable method of pollination.
In conclusion, maize is cross pollinated by wind due to its unique reproductive structure and the release of lightweight pollen grains. This method of pollination ensures the successful fertilization of a large number of ears, making it a crucial factor in the cultivation of maize crops.

Male Gametes in a Flower
The male gametes (pollen grains) in a flower are produced by the stamens.
Explanation:
Flowers are the reproductive structures of angiosperms (flowering plants). They contain both male and female reproductive organs, which are responsible for the production of male and female gametes.
Here's a breakdown of the various flower parts and their functions:
1. Sepals: Sepals are the outermost whorl of a flower, usually green in color. They protect the developing flower bud but do not produce male gametes.
2. Petals: Petals are the colorful, often showy parts of a flower that attract pollinators. They play a role in pollination but do not produce male gametes.
3. Carpels: Carpels are the female reproductive organs of a flower. They consist of the stigma, style, and ovary. Carpels produce female gametes (eggs) but not male gametes.
4. Stamens: Stamens are the male reproductive organs of a flower. They consist of the anther and filament. The anther is responsible for producing pollen grains, which contain the male gametes (sperm cells). The filament supports the anther.
Therefore, the correct answer is D: stamens. Stamens produce male gametes in a flower.

The Answer is B: Stigma
During pollination, pollen grains are transferred from the anther (male reproductive structure) to the carpel (female reproductive structure) of a flower. The carpel is composed of three main parts: the stigma, style, and ovary. The stigma is the topmost part of the carpel and plays a crucial role in pollination.
Here is a detailed explanation of the process:
1. Pollination: Pollination is the transfer of pollen grains from the anther to the carpel of a flower. It can occur through various means, such as wind, water, or with the help of animals (insects, birds, etc.).
2. Carpel Structure: The carpel is the female reproductive structure of a flower and is composed of three main parts:
- Stigma: The stigma is the sticky or feathery topmost part of the carpel. Its main function is to receive the pollen grains. The sticky surface of the stigma helps in capturing and retaining pollen.
- Style: The style is a slender tube-like structure that connects the stigma to the ovary. It provides a pathway for the pollen grains to reach the ovary.
- Ovary: The ovary is the swollen base of the carpel. It contains one or more ovules, which are potential seeds. After pollination, the ovary develops into a fruit, and the fertilized ovules become seeds.
3. Pollen Grain Transfer: When a pollinator (such as a bee) visits a flower, it may inadvertently brush against the anther and pick up pollen grains. The pollinator then moves to another flower of the same species.
4. Stigma Receptor: When the pollinator lands on a flower, the pollen grains on its body may come into contact with the stigma. The sticky surface of the stigma helps in the adhesion of the pollen grains.
5. Pollen Tube Formation: Once the pollen grains are on the stigma, they germinate and form pollen tubes. These tubes elongate through the style and reach the ovary.
6. Fertilization: The pollen tubes deliver sperm cells to the ovules in the ovary. Fertilization occurs when the sperm cells fuse with the egg cells inside the ovule. This process leads to the formation of a seed.
In conclusion, during pollination, pollen grains get carried to the stigma of the carpel. The sticky stigma plays a vital role in capturing and facilitating the germination of pollen grains, leading to the fertilization and formation of seeds.

The pollen tube has two male nuclei at the time of entering into the ovule.
Explanation:
- The pollen tube is a structure that is formed by the pollen grain after it lands on the stigma of the flower.
- It grows through the style of the flower towards the ovule, which is located in the ovary.
- The main function of the pollen tube is to deliver the male gametes (sperm cells) to the ovule for fertilization.
- As the pollen tube grows, it contains two male nuclei within it.
- These two nuclei are called the generative nucleus and the tube nucleus.
- The generative nucleus divides to form two male gametes (sperm cells).
- The tube nucleus helps in the growth and elongation of the pollen tube.
- The pollen tube enters the ovule through the micropyle, a small opening in the ovule's integument.
- Once inside the ovule, the pollen tube releases the male gametes, which then fertilize the female gamete (egg cell) present in the ovule.
- This fertilization process leads to the formation of a zygote, which eventually develops into an embryo.
- The two male nuclei present in the pollen tube play a crucial role in the successful fertilization of the ovule.

Transfer of pollen grains from anther to stigma:
- Pollination: The correct term for the transfer of pollen grains from the anther (the male reproductive organ) to the stigma (the female reproductive organ) is pollination.
- Definition: Pollination is the process by which pollen grains are transferred from the anther to the stigma, allowing for the fertilization of the ovules and the production of seeds.
- Methods of pollination: Pollination can occur through various methods, including wind pollination, insect pollination, bird pollination, and self-pollination.
- Wind pollination: In wind pollination, the pollen grains are light and small, and they are easily carried by the wind to the female reproductive organs.
- Insect pollination: Insect pollination involves the transfer of pollen grains by insects, such as bees, butterflies, and beetles, as they visit flowers in search of nectar.
- Bird pollination: Bird pollination occurs when birds, such as hummingbirds, feed on the nectar of flowers and inadvertently transfer pollen grains between flowers.
- Self-pollination: Self-pollination happens when pollen from the anther is transferred to the stigma of the same flower or a different flower on the same plant.
- Importance of pollination: Pollination is vital for the reproduction of flowering plants as it enables the transfer of genetic material and the production of seeds, which leads to the growth and survival of plant species.
In conclusion, the correct term for the transfer of pollen grains from anther to stigma is pollination. Pollination is a crucial process that ensures the reproduction and survival of flowering plants.

Fertilization in plants occurs in the:
There are several structures involved in the process of fertilization in plants. The correct answer is A, the embryo sac. Here is a detailed explanation of the process:
1. Pollination:
- Pollination is the transfer of pollen grains from the anther to the stigma of a flower.
- It can occur through various means, including wind, water, or by animal pollinators such as bees or butterflies.
2. Germination of pollen:
- Once the pollen grain reaches the stigma, it germinates and develops a pollen tube.
- The pollen tube grows through the style, a structure that connects the stigma to the ovary.
3. Pollen tube growth:
- The pollen tube grows down the style towards the ovary.
- It is responsible for delivering the sperm cells contained within the pollen grain to the embryo sac.
4. Embryo sac:
- The embryo sac is a structure located within the ovary of the flower.
- It contains the female gametophyte, which includes the egg cell.
5. Fertilization:
- When the pollen tube reaches the embryo sac, it releases the sperm cells.
- One of the sperm cells fertilizes the egg cell, resulting in the formation of a zygote.
- The other sperm cell combines with other cells in the embryo sac to form endosperm, which provides nourishment to the developing embryo.
6. Seed development:
- After fertilization, the zygote develops into an embryo, and the ovule develops into a seed.
- The seed contains the embryo, endosperm, and a protective seed coat.
Overall, fertilization in plants occurs within the embryo sac, where the sperm cells from the pollen tube fuse with the egg cell, leading to the formation of a zygote and the development of a seed.

Stem cutting propagation:
Stem cutting is a common method used for propagation in various plants. When a stem cutting is taken from a parent plant and rooted in a suitable growing medium, it can develop into a new plant with identical genetic characteristics. In this case, stem cutting propagation is commonly used for the plants listed below:
A. Mango:
- Mango plants can be propagated through stem cuttings.
- Mature branches with a diameter of about 1-2 inches are selected as cutting material.
- The cuttings are treated with a rooting hormone and planted in a well-draining potting mix.
- They are then kept in a warm and humid environment until roots develop.
B. Jasmine:
- Jasmine plants can also be propagated through stem cuttings.
- Softwood cuttings, taken from the tips of healthy branches, are ideal for propagation.
- The cuttings are dipped in a rooting hormone and planted in a well-draining soil mix.
- They are placed in a warm and moist environment until roots form.
C. Cotton:
- Cotton plants can be propagated through stem cuttings as well.
- Cuttings are taken from healthy branches and treated with a rooting hormone.
- They are then placed in a suitable rooting medium, such as a mixture of sand and peat.
- The cuttings are kept in a warm and humid environment until roots develop.
D. Sugarcane:
- Sugarcane is commonly propagated through stem cuttings.
- Mature stems are cut into sections, each containing at least one bud.
- These sections are then planted in a well-prepared soil or a suitable rooting medium.
- Adequate moisture and warmth are provided to promote root development.
In conclusion, stem cutting propagation is commonly used for plants like mango, jasmine, cotton, and sugarcane. By following the appropriate techniques and providing the necessary conditions, new plants can be successfully grown from stem cuttings.

Vegetative Reproduction in Plants
Vegetative reproduction is a form of asexual reproduction in plants where new individuals are produced from vegetative structures of the parent plant, such as stems, roots, or leaves. In the case of citrus, jasmine, and grapevine, the process of vegetative reproduction is commonly achieved through stem layering.
Stem Layering:
This method involves the following steps:
- Select a healthy and mature stem from the parent plant.
- Make a small incision on the selected stem, typically near a leaf node.
- Apply a rooting hormone to the wounded area to encourage root development.
- Bury the wounded portion of the stem underground, leaving the tip exposed.
- Secure the buried portion of the stem with soil or a pot to maintain contact with the soil.
- Over time, the buried portion of the stem will develop roots, and eventually, a new individual plant will form.
- Once the new plant is well-established with a strong root system, it can be separated from the parent plant and grown independently.
Other Methods of Vegetative Reproduction:
Although stem layering is the primary method of vegetative reproduction for citrus, jasmine, and grapevine, it is worth noting that these plants can also be propagated through other means, such as:
- Stem Cutting: In this method, a healthy stem is cut from the parent plant and directly planted or placed in a suitable growing medium to develop roots and form a new plant.
- Stem Grafting: This technique involves joining the stem of the desired plant variety (scion) to the rooted stem of another plant (rootstock) to combine their desirable traits. Grafting is commonly used in horticulture to produce plants with specific characteristics.
Conclusion:
In conclusion, vegetative reproduction in plants like citrus, jasmine, and grapevine is primarily achieved through stem layering. However, these plants can also be propagated through stem cutting and stem grafting methods. Each method offers its own advantages and is used depending on the specific goals and requirements of the plant propagation process.

Asexual reproduction includes the following methods:

1. Fission: In fission, an organism divides into two or more offspring of the same size. This can occur in different ways:




• Binary fission: The parent organism splits into two identical daughter cells. Examples include bacteria and amoebas.


• Multiple fission: The parent organism divides into multiple offspring simultaneously. This process is observed in organisms like Plasmodium, a parasite that causes malaria.




2. Budding: Budding is a form of asexual reproduction in which a new organism develops from an outgrowth or bud on the parent organism. The bud then detaches and becomes an independent individual. Examples include yeast and Hydra.


3. Vegetative propagation: Vegetative propagation involves the development of new individuals from vegetative parts of a plant, such as roots, stems, and leaves. This method is commonly used in horticulture and agriculture to reproduce plants with desirable traits. Examples include runners in strawberry plants and tubers in potatoes.

Therefore, the correct answer is option D: All of these. Asexual reproduction can occur through fission, budding, and vegetative propagation.

Binary fission occurs in:

• Plasmodium: Binary fission does not occur in Plasmodium. Plasmodium reproduces through a process called multiple fission, where the nucleus divides several times before the cell divides into multiple daughter cells.


• Hydra: Binary fission does not occur in Hydra. Hydra reproduces through a process called budding, where a small outgrowth called a bud forms on the parent organism and eventually detaches to become a new individual.


• Pomegranate: Binary fission does not occur in Pomegranate. Pomegranate reproduces through sexual reproduction, where male and female gametes fuse to form a zygote.


• Amoeba: Binary fission occurs in Amoeba. Amoeba is a single-celled organism that reproduces asexually by dividing itself into two daughter cells through binary fission. The nucleus of the cell undergoes mitosis, followed by the division of the cytoplasm, resulting in the formation of two genetically identical daughter cells.

Therefore, the correct answer is D. Amoeba.

Multiple Fission in Different Organisms:
Euglena:
- Euglena does not undergo multiple fission.
- It reproduces asexually by binary fission, where the parent cell divides into two daughter cells.
Yeast:
- Yeast also does not undergo multiple fission.
- It reproduces asexually by budding, where a small bud forms on the parent cell and eventually separates to become a new individual.
Plasmodium:
- Plasmodium, a protozoan parasite that causes malaria, undergoes multiple fission.
- During its life cycle, Plasmodium replicates within the red blood cells of the host.
- It goes through a process called schizogony or merogony, where the nucleus divides multiple times, followed by the division of cytoplasm.
- This results in the formation of multiple daughter cells called merozoites, which can infect new red blood cells.
Paramecium:
- Paramecium undergoes a type of multiple fission called binary fission.
- It first undergoes nuclear division, followed by the division of the cytoplasm.
- This results in the formation of two daughter cells, each with a complete set of organelles and genetic material.
Conclusion:
- Among the given options, only Plasmodium undergoes multiple fission.
- Multiple fission is an important reproductive strategy for Plasmodium to increase its population within the host and spread the infection.

Reproduction and Parental Identity:
In certain types of reproduction, parental identity is lost. Let's explore the different methods of reproduction mentioned in the question and identify which ones result in the loss of parental identity.
Budding:
- Budding is a form of asexual reproduction where a new individual grows out of the parent organism.
- In budding, a small bud or outgrowth develops on the parent organism and eventually detaches to become a separate individual.
- Parental identity is not lost in budding, as the new individual is genetically identical to the parent.
Binary Fission:
- Binary fission is a method of reproduction used by single-celled organisms, such as bacteria.
- In binary fission, the parent organism divides into two equal-sized daughter cells, each with identical genetic material.
- Parental identity is not lost in binary fission, as both daughter cells are genetically identical to the parent.
Multiple Fission:
- Multiple fission is a method of reproduction observed in certain protists, such as Plasmodium (the causative agent of malaria).
- In multiple fission, the parent organism undergoes multiple rounds of nuclear division, resulting in the formation of multiple daughter cells.
- These daughter cells are genetically identical to each other but different from the parent organism.
- Parental identity is lost in multiple fission, as the parent organism is ultimately replaced by multiple offspring.
Conclusion:
Based on the above explanations, it can be concluded that parental identity is lost in Multiple Fission (C). Both binary fission and budding do not result in the loss of parental identity.

Organisms that show budding:
- Spirogyra: Spirogyra is a filamentous green algae that reproduces mainly through fragmentation, not budding.
- Hydra: Hydra is a freshwater organism that reproduces asexually through budding. It forms small outgrowths called buds that eventually separate and develop into independent individuals.
- Amoeba: Amoeba is a unicellular organism that reproduces mainly through binary fission, not budding. It divides into two daughter cells of equal size.
- Paramecium: Paramecium is a unicellular organism that reproduces mainly through binary fission, not budding. It divides into two daughter cells of equal size.
Therefore, the correct answer is Hydra as it shows budding for asexual reproduction.

Condom is a method of control that falls under the category of Mechanical Method.

Condoms are widely used as a method of contraception and STI prevention. They are known as a mechanical method of control because they physically prevent sperm from reaching the egg and also provide a barrier against sexually transmitted infections.

Here are some key points to explain why condoms are considered a mechanical method:
- Physical barrier: Condoms are made of thin, flexible material such as latex or polyurethane. They act as a physical barrier, preventing sperm from entering the vagina during sexual intercourse. This ensures that the sperm cannot reach the egg for fertilization.
- Protection against STIs: In addition to preventing pregnancy, condoms also provide protection against sexually transmitted infections (STIs). They create a barrier that helps to prevent the transmission of STI-causing organisms such as bacteria and viruses.
- External application: Condoms are applied externally to the penis before sexual intercourse. They are rolled onto the erect penis and must be used correctly to ensure effectiveness. This distinguishes them from other methods that involve internal placement or hormonal administration.
- Availability and accessibility: Condoms are widely available and accessible. They can be purchased over-the-counter without a prescription and are often distributed for free in clinics, schools, and community health programs. This makes them a convenient and affordable option for many individuals.
- Non-hormonal: Unlike hormonal methods such as birth control pills or patches, condoms do not contain any hormones. They do not alter the body's hormonal balance and do not require a doctor's prescription. This makes them a suitable choice for individuals who prefer non-hormonal contraception.
In conclusion, condoms are considered a mechanical method of control because they physically prevent sperm from reaching the egg and provide a barrier against sexually transmitted infections. They are widely accessible, non-hormonal, and provide dual protection against pregnancy and STIs.

The testes perform the following functions:
Produce male gametes and hormone:
- The primary function of the testes is to produce male gametes, also known as sperm cells. These sperm cells are necessary for sexual reproduction.
- The testes also produce the hormone testosterone, which is responsible for the development of male secondary sexual characteristics, such as facial hair, deepening of the voice, and muscle growth.
In summary, the testes play a crucial role in male reproduction by producing sperm cells and the hormone testosterone.

Where does fertilisation take place in human beings?


Fertilisation is the process of fusion of the sperm and egg, resulting in the formation of a zygote. In human beings, fertilisation takes place in the fallopian tube, also known as the oviduct. Here is a detailed explanation:
Fallopian Tube:
- The fallopian tube is a muscular tube that connects the ovaries to the uterus.
- It has finger-like projections called fimbriae at the end near the ovary, which help in capturing the released egg during ovulation.
- The tube has a narrow lumen lined with ciliated epithelial cells that help in the movement of the egg towards the uterus.
- After ovulation, the egg is released from the ovary and enters the fallopian tube.
- If sexual intercourse occurs around the time of ovulation and sperm are present in the reproductive tract, the sperm travel through the uterus and enter the fallopian tube.
- Fertilisation takes place in the ampulla, which is the widest part of the fallopian tube.
- The sperm must penetrate the protective layers surrounding the egg and fuse with its membrane to form a zygote.
- The fertilised egg, or zygote, then begins to divide and travel towards the uterus for implantation.
In conclusion, fertilisation takes place in the fallopian tube in human beings.

Asexual Reproduction in Spirogyra

• Fission: Fission is the process of asexual reproduction in which the parent organism divides into two or more daughter cells. However, this method is not observed in Spirogyra.


• Budding: Budding is a form of asexual reproduction in which a small outgrowth or bud develops on the parent organism and eventually detaches to become an independent individual. This method is not observed in Spirogyra.


• Fragmentation: Fragmentation is the mode of asexual reproduction in Spirogyra. It involves the breaking of the filamentous Spirogyra into fragments, which then grow into new individuals.


• Multiple Fission: Multiple fission is a type of asexual reproduction in which the parent organism divides into multiple daughter cells simultaneously. This method is not observed in Spirogyra.

Therefore, the correct answer is fragmentation. In Spirogyra, asexual reproduction occurs through fragmentation, where the filamentous organism breaks into fragments that grow into new individuals.

The part of the flower that forms the fruit is the ovary.
The ovary is a part of the pistil, which is the female reproductive organ of a flower. It is located at the base of the flower and contains one or more ovules, which are the structures that develop into seeds.
When a flower is pollinated, pollen from the male reproductive organs (stamens) is transferred to the pistil. The pollen then travels down the pistil and fertilizes the ovules inside the ovary. This process triggers the development of the ovary into a fruit.
Here is a breakdown of the different parts of the flower and their roles in fruit formation:
- Stamens: These are the male reproductive organs of the flower. They consist of a filament and an anther, which produces pollen. The pollen is transferred to the pistil during pollination.
- Carpels: These are the female reproductive organs of the flower. They consist of an ovary, style, and stigma. The ovary contains the ovules, which develop into seeds when fertilized.
- Ovary: This is the swollen base of the pistil that contains the ovules. After fertilization, the ovary develops into a fruit, protecting and nourishing the developing seeds.
So, while both stamens and carpels are involved in the process of pollination and fertilization, it is the ovary that ultimately forms the fruit.

After fertilization, the ovule grows into a seed. Here is a detailed explanation:
The process of fertilization:
- Fertilization is the process in which the male gamete (pollen) fuses with the female gamete (ovule) to form a zygote.
- After pollination, the pollen tube grows through the stigma and style to reach the ovary, where the ovule is located.
- The pollen tube delivers the male gamete to the ovule, and fertilization occurs when the nuclei of the male and female gametes fuse.
The development of the ovule into a seed:
- After fertilization, the ovule undergoes several changes and develops into a seed.
- The zygote formed during fertilization divides and develops into an embryo. The embryo consists of the embryonic root, shoot, and cotyledons.
- The ovule's integuments (outer protective layers) develop into the seed coat, which provides protection to the developing embryo.
- The ovule's nucellus (central part) becomes the nutritive tissue called the endosperm, which provides nourishment to the developing embryo.
- As the embryo continues to grow, the ovule matures into a seed, containing the embryo, endosperm, and seed coat.
Therefore, after fertilization, the ovule grows into a seed, which is an important reproductive structure in plants.

The correct answer is A: Grafting.


Grafting is a horticultural technique in which a cutting part of a plant, called the scion, is attached to the stem or root of another plant, called the rootstock or stock. This creates a new plant that combines the desired traits of both the scion and the rootstock. Here's a detailed explanation of grafting:
1. What is grafting?
- Grafting is a method of asexual propagation used in horticulture and agriculture.
- It involves joining two different plant parts in such a way that they grow together and form a single plant.
2. How is grafting done?
- The process of grafting begins with selecting a scion, which is a piece of the desired plant that carries the traits you want to reproduce.
- The scion is usually a stem with leaves or buds.
- The next step is to prepare the rootstock, which is the plant onto which the scion will be grafted.
- The rootstock is selected based on its compatibility with the scion and its ability to provide the desired root system.
- The scion and rootstock are then connected by making a cut on both plants and joining them together.
- Various grafting techniques, such as whip grafting, cleft grafting, and bud grafting, can be used depending on the plants involved.
3. Why is grafting done?
- Grafting is done for various reasons, including:
- To propagate desirable plant varieties that cannot be easily grown from seeds.
- To combine the desirable traits of different plants into a single plant.
- To repair damaged plants or replace diseased or weak root systems.
- To create dwarf or compact plants by grafting onto rootstocks with restricted growth.
4. Advantages of grafting:
- Grafting allows for the production of plants with improved characteristics, such as disease resistance, increased fruit production, or specific flower colors.
- Grafting can be used to create plants that are better adapted to specific environmental conditions or growing techniques.
- Grafting can shorten the time required for a plant to start producing flowers or fruits compared to growing from seeds.
- Grafting allows for the preservation and propagation of rare or endangered plant species.
In conclusion, grafting is a method of plant propagation in which a cutting part of a plant is attached to another plant part. It is a valuable technique used in horticulture and agriculture to produce plants with desired traits and characteristics.

Stamen:
The stamen is the male reproductive part of a flower. It consists of several components, including the filament and the anther. The stamen plays a crucial role in the process of pollination and fertilization in plants.
Components of the stamen:
- Filament: The filament is a long, slender stalk that supports the anther. It is usually thin and flexible, allowing the anther to be positioned where it can easily release pollen.
- Anther: The anther is the top part of the stamen and contains pollen sacs. These sacs produce and store pollen grains, which contain the male gametes required for fertilization.
- Stigma: The stigma is not a part of the stamen but is part of the female reproductive structure of the flower called the pistil. It is the sticky structure at the top of the pistil that collects pollen during pollination.
Conclusion:
In summary, the filament is a part of the stamen, along with the anther. The stigma, on the other hand, is part of the pistil, which is the female reproductive structure of the flower.

Asexual reproduction involves:
There are several key points to understand about asexual reproduction:
1. Only one parent: Asexual reproduction is a type of reproduction that involves only one parent. This means that offspring are produced without the need for a mate or the fusion of gametes.
2. No meiosis and syngamy: Unlike sexual reproduction, asexual reproduction does not involve the processes of meiosis and syngamy. Meiosis is the process of cell division that produces gametes with half the number of chromosomes, while syngamy is the fusion of two gametes to form a new individual.
3. No fusion of gametes: In asexual reproduction, there is no fusion of gametes (reproductive cells) from two different individuals. Instead, the parent organism reproduces by producing offspring that are genetically identical to itself.
4. Methods of asexual reproduction: There are several methods of asexual reproduction, including binary fission, budding, fragmentation, and vegetative propagation. Each method involves the parent organism producing offspring without the involvement of another individual.
Overall, asexual reproduction is a type of reproduction that involves only one parent and does not require the processes of meiosis, syngamy, or the fusion of gametes. It is a common method of reproduction in many organisms, including bacteria, plants, and some animals.

The common passage for sperms and urine in the male reproductive system is the Urethra.
The male reproductive system is responsible for producing and delivering sperm for reproduction. The urethra serves as a common passage for both urine and sperm in the male reproductive system. Here is a detailed explanation:
1. Urethra:
- The urethra is a tube that connects the urinary bladder to the external opening of the penis.
- It serves as a passage for both urine and semen.
- The urethra has three main parts: the prostatic urethra, the membranous urethra, and the spongy (penile) urethra.
2. Sperm Production:
- Sperm is produced in the testes, which are located in the scrotum.
- After production, sperm moves to the epididymis, where they mature and are stored.
3. Sperm Transportation:
- When a male ejaculates, the sperm travel through the vas deferens, also known as the ductus deferens.
- The vas deferens is a muscular tube that connects the epididymis to the urethra.
- It carries sperm from the testes to the urethra during ejaculation.
4. Seminal Vesicle:
- The seminal vesicles are located behind the bladder and secrete a fluid that mixes with sperm to form semen.
- While seminal vesicles play a crucial role in reproduction, they are not directly involved in the common passage for sperms and urine.
5. Ureter:
- The ureter is a tube that connects the kidneys to the urinary bladder.
- It carries urine from the kidneys to the bladder.
- Although the ureter is part of the urinary system, it is not involved in the common passage for sperms and urine in the male reproductive system.
Therefore, the correct answer is option C: Urethra. The urethra serves as the common passage for both urine and sperm in the male reproductive system.