Test: Animal Reproduction - 3 - Class 10 MCQ

Vegetative propagation in Bryophyllum takes place by leaf.
Vegetative propagation is a form of asexual reproduction in plants where new individuals are produced from vegetative structures such as leaves, stems, and roots. In the case of Bryophyllum, it primarily occurs through the leaf.
Here is a detailed explanation of how vegetative propagation takes place in Bryophyllum through leaves:
1. Leaf morphology: Bryophyllum leaves are succulent and fleshy, with specialized structures called plantlets or bulbils present along the leaf margins.
2. Formation of plantlets: As the leaf grows, small adventitious buds or plantlets develop along the notches of the leaf margins. These plantlets have the potential to form a new plant.
3. Leaf detachment and propagation: Once the plantlets are mature enough, they can detach from the parent leaf and fall to the ground. They have the ability to take root and establish themselves as independent plants.
4. Root development: Upon falling to the ground, the plantlets develop roots that anchor them into the soil. These roots provide the plantlets with water and nutrients for growth.
5. Growth and development: With a steady supply of water and nutrients, the plantlets grow into fully functional plants. They can eventually produce their own leaves and undergo the process of vegetative propagation through leaf formation.
In conclusion, Bryophyllum exhibits vegetative propagation primarily through the formation of plantlets along the leaf margins. This adaptive mechanism allows Bryophyllum to reproduce asexually and colonize new areas efficiently.

A group of petals are called Corolla. So here Corolla I'm not in the option. That's why option ( d) is the correct answer.

Grafting or graftage is a horticultural technique whereby tissues of plants are joined so as to continue their growth together. The upper part of the combined plant is called the scion while the lower part is called the rootstock.

Answer:
The correct method commonly used to produce new plants in roses is cutting. Here is a detailed explanation of the process:
1. Cutting: This is the most common method used to propagate roses. It involves taking a stem or branch from an existing rose plant and encouraging it to develop roots and grow into a new plant.
2. Selecting the cutting: Choose a healthy stem that is around 6-8 inches long and has several sets of leaves. Make sure the stem is free from any diseases or pests.
3. Preparing the cutting: Remove any flowers or buds from the stem and make a clean cut just below a leaf node. This is where the new roots will develop.
4. Rooting hormone: Dip the cut end of the stem into a rooting hormone powder or gel. This will help stimulate root growth and increase the chances of successful rooting.
5. Potting the cutting: Fill a small pot with a well-draining potting mix. Make a hole in the soil and insert the cutting, ensuring that at least two leaf nodes are buried in the soil. Gently press the soil around the cutting to secure it in place.
6. Watering and care: Water the cutting thoroughly and place it in a warm and bright location, but out of direct sunlight. Keep the soil moist but not waterlogged. Mist the cutting regularly to maintain high humidity.
7. Root development: After a few weeks, the cutting should start developing roots. You can gently tug on the stem to check for resistance, indicating that roots have formed.
8. Transplanting: Once the cutting has established a good root system, it can be transplanted into a larger pot or into the ground. Provide the newly rooted rose plant with proper care, including regular watering, fertilization, and protection from pests and diseases.
By following these steps, you can successfully produce new rose plants through the cutting method.

Production of Pollen Grains:
Pollen grains are the male reproductive cells of flowering plants. They are produced in the anther, which is part of the flower's reproductive organ called the stamen. Here is a detailed explanation of how pollen grains are produced:
Anther:
- The anther is the part of the flower's stamen where pollen grains are produced.
- It is typically located at the top of a filament, which is a slender stalk-like structure.
- The anther consists of pollen sacs that contain pollen mother cells.
Pollen Mother Cells:
- Within the pollen sacs of the anther, there are specialized cells called pollen mother cells.
- These cells undergo meiosis, a type of cell division, to produce haploid cells known as microspores.
Microspores:
- Each pollen mother cell undergoes meiosis to produce four microspores.
- These microspores are genetically diverse due to the process of recombination during meiosis.
- Each microspore has half the number of chromosomes as the pollen mother cell.
Pollen Grains:
- Each microspore develops into a pollen grain.
- The pollen grain is a tiny, single-celled structure that contains the male gametes (sperm cells) of the plant.
- The pollen grain is protected by a tough outer layer called the exine, which helps it withstand harsh environmental conditions.
Pollen Dispersal:
- Once the pollen grains are fully developed, they are released from the anther.
- Various methods are involved in pollen dispersal, including wind, water, insects, birds, and other animals.
- The ultimate goal of pollen dispersal is to reach the stigma of a compatible flower for pollination and fertilization to occur.
In conclusion, pollen grains are produced in the anther, which is part of the flower's stamen. They are formed through the process of meiosis from pollen mother cells, and each microspore develops into a pollen grain containing the male gametes. The pollen grains are then dispersed for the purpose of pollination and fertilization.

Sepals are green outermost leaf  like floral organs, also called calyx. A group of petals are called Corolla.

Maize is cross pollinated by wind
Maize, also known as corn, is a cereal crop that reproduces through cross-pollination. It is primarily pollinated by wind, which carries pollen from the male flowers (tassels) to the female flowers (silks). Here's a detailed explanation of why maize is cross-pollinated by wind:
1. Structure of maize flowers:
- Maize plants have separate male and female flowers.
- The male flowers, located on the tassels at the top of the plant, produce pollen.
- The female flowers, located on the ear or cob, have long, thread-like structures called silks.
2. Pollination process:
- When the male flowers mature, they release pollen into the air.
- The wind carries the pollen grains to the female flowers.
- Each silk on the ear is connected to a potential kernel.
- When a pollen grain lands on a silk, it travels down the silk to reach the ovary.
- Fertilization occurs when the pollen grain reaches the ovary, resulting in the development of a kernel.
3. Advantages of wind pollination in maize:
- Wind pollination allows for efficient pollination over large distances.
- It eliminates the need for external agents like insects or animals for pollination.
- The abundant production of pollen by the tassels ensures a higher chance of successful pollination.
4. Challenges of wind pollination:
- The reliance on wind for pollination means that environmental conditions, such as wind speed and direction, can affect the efficiency of pollination.
- The presence of nearby maize fields or other plants with compatible flowering periods is important to ensure successful cross-pollination.
In conclusion, maize is cross-pollinated by wind due to its specific flower structure and the advantages it offers in terms of efficient pollination over large distances. The reliance on wind for pollination is an adaptation that ensures the production of viable kernels in maize plants.

At the time of pollination, tube nucleus is present, i.e. the pollen grain is usually 3-celled (tube cell + two male gametes). the tube nucleus degenerate when the pollen tube enters the ovary. So, at the time of entering into ovule, the pollen tube has 2 male nuclei.

Fertilization in plants occurs in the:
There are several key stages in the process of fertilization in plants:
1. Pollination:
- Pollination is the transfer of pollen from the anther to the stigma of a flower.
- It can occur through various means, such as wind, water, or animal pollinators.
2. Pollen germination:
- Once a pollen grain lands on a compatible stigma, it absorbs moisture and germinates.
- A pollen tube begins to grow from the pollen grain towards the ovary.
3. Pollen tube growth:
- The pollen tube grows through the style, a long tubular structure connecting the stigma to the ovary.
- It is through this tube that the male gametes (sperm cells) travel towards the ovules.
4. Fertilization:
- When the pollen tube reaches the ovary, it enters the embryo sac, which is located within the ovule.
- The male gametes are released from the pollen tube and fertilize the female gametes within the embryo sac.
- This process leads to the formation of a zygote, which will develop into an embryo.
5. Seed development:
- After fertilization, the ovule develops into a seed, which contains the embryo.
- The seed also develops a protective seed coat and stores nutrients for the developing embryo.
In conclusion, fertilization in plants occurs in the embryo sac, which is located within the ovule. The process involves pollination, pollen germination, pollen tube growth, fertilization within the embryo sac, and subsequent seed development.

Vegetative reproduction in plants like citrus, jasmine, and grapevine is done by the process of stem layering.
Stem layering is a method of vegetative propagation where a stem is bent and partially buried in the soil to encourage the growth of roots. This allows the stem to develop into an independent plant.
Here is a detailed explanation of the process of stem layering:
1. Select a healthy and mature stem: Choose a stem that is flexible and has not become woody yet. It should be free from diseases or infections.
2. Prepare the stem for layering: Make a small cut or wound on the lower side of the stem. This will help in the development of roots.
3. Bury the stem in the soil: Bury the wounded part of the stem in the soil, leaving the tip above the ground. Ensure that the buried part is securely anchored in the soil to prevent it from moving or being damaged.
4. Provide necessary conditions: Keep the soil moist and provide proper sunlight to the stem. This will promote the growth of roots from the buried part.
5. Wait for root formation: After some time, roots will start to develop from the buried part of the stem. You can gently check for root growth by carefully digging around the buried stem.
6. Separate the new plant: Once sufficient roots have formed, you can separate the new plant from the parent plant by cutting it below the rooted portion. Transplant the new plant to a suitable location or container.
Stem layering is an effective method of vegetative reproduction as it allows plants to produce genetically identical offspring without the need for seeds. It is commonly used in horticulture to propagate desirable plant varieties with specific traits.

Asexual reproduction methods include:
- Fission: This is a form of asexual reproduction where a single organism divides into two or more individuals of the same species. It can occur through binary fission, where the organism splits into two equal halves, or multiple fission, where the organism divides into more than two parts.
- Budding: Budding is a type of asexual reproduction in which a new organism is formed from an outgrowth or bud on the parent organism. The bud grows and eventually detaches from the parent, becoming an independent organism.
- Vegetative propagation: Vegetative propagation is a method of asexual reproduction in plants. It involves the growth and development of new plants from vegetative parts such as stems, roots, or leaves. Examples of vegetative propagation include runners, rhizomes, tubers, bulbs, and plantlets.
Therefore, the correct answer is: D: All of these

Binary fission occurs in:
Binary fission is a form of asexual reproduction where a single organism divides into two identical offspring. It is a common method of reproduction in many organisms. In this case, binary fission occurs in Amoeba.
Explanation:
Amoeba is a unicellular organism belonging to the phylum Protozoa. It reproduces through binary fission, a process that involves the following steps:
1. Growth: The Amoeba grows in size by feeding on bacteria and other small organisms.
2. DNA replication: The DNA in the nucleus of the Amoeba is replicated, ensuring that each offspring will receive a complete set of genetic material.
3. Division: The cell membrane of the Amoeba constricts, dividing the organism into two identical halves.
4. Formation of daughter cells: Each half of the divided Amoeba forms a separate daughter cell, which is genetically identical to the parent cell.
5. Separation: The two daughter cells separate from each other and continue to grow independently.
Binary fission is a rapid and efficient method of reproduction for Amoeba, allowing them to quickly increase their population size under favorable conditions.
Therefore, binary fission occurs in Amoeba.

Multiple Fission in Different Organisms:
Euglena:
- Euglena is a unicellular organism that belongs to the phylum Euglenozoa.
- It reproduces asexually by a process called binary fission, where the parent cell divides into two daughter cells.
- Multiple fission does not occur in Euglena.
Yeast:
- Yeast is a single-celled fungus that belongs to the genus Saccharomyces.
- It reproduces asexually by a process called budding, where a small bud grows on the parent cell and eventually detaches to form a new individual.
- Multiple fission does not occur in yeast.
Plasmodium:
- Plasmodium is a parasitic protozoan that causes malaria in humans.
- It reproduces asexually by a process called schizogony or multiple fission.
- In schizogony, the nucleus of the parent cell undergoes multiple divisions to form several daughter nuclei, which are then enclosed in separate cytoplasmic fragments to form daughter cells.
- These daughter cells, known as merozoites, are released into the bloodstream and invade new red blood cells, continuing the infection cycle.
Paramecium:
- Paramecium is a ciliated protozoan that belongs to the phylum Ciliophora.
- It reproduces asexually by a process called binary fission, where the parent cell divides transversely into two daughter cells.
- Multiple fission does not occur in Paramecium.
Therefore, the correct answer is C: Plasmodium. Plasmodium undergoes multiple fission or schizogony during its asexual reproduction.

In binary fission, parental identity is lost. In this, the parental cell divides into two daughter cells having identical genotype. In multiple fission, the Nucleus of the parental cell divides several times and produces several daughter cells. In this type also parental identity is lost. 

To answer the question, we need to understand the different types of pollination and their definitions:
1. Allogamy: Allogamy refers to the transfer of pollen from the anther of one flower to the stigma of another flower. It involves cross-pollination between different flowers of the same species.
2. Geitonogamy: Geitonogamy occurs when the pollen from the anther of one flower is transferred to the stigma of another flower on the same plant. It is a form of cross-pollination within the same plant.
3. Autogamy: Autogamy refers to the transfer of pollen from the anther to the stigma of the same flower. It is a form of self-pollination within a single flower.
Now let's apply these definitions to the given question:
- If the pollen is transferred to the stigma of the same flower, then it means the pollination is occurring within a single flower.
- This matches the definition of autogamy, where self-pollination takes place within the same flower.
Therefore, the correct answer is C: autogamy.

Endosperm is formed during the double fertilization. It is triploid because it is formed when one of two sperm that is haploid enters inside the embryo sac and fuses with two polar nuclei ( each polar nuclei is haploid). So the endosperm formed is triploid.

After fertilization, the ovule grows into a seed.

• The process of fertilization involves the fusion of the male gamete (pollen) with the female gamete (ovule) to form a zygote.


• After fertilization, the ovule undergoes several changes and transforms into a seed.


• Here are the key steps in the development of the ovule into a seed:




• Fertilization: The pollen tube delivers the male gamete to the ovule, where it fuses with the female gamete, resulting in fertilization.


• Embryo development: The zygote develops into an embryo, which consists of the embryonic axis (root and shoot) and the cotyledons.


• Endosperm formation: The endosperm, which provides nourishment to the developing embryo, is formed through the fusion of the polar nuclei with a second sperm cell.


• Seed coat formation: The outer covering of the seed, known as the seed coat, develops from the integuments of the ovule.


• Maturation: The embryo and endosperm continue to develop, and the seed matures, acquiring the ability to survive in a dormant state until conditions are favorable for germination.

Therefore, the correct answer is A: seed.

Answer:
The correct answer is option C: Anther. The anther is not a part of the carpel, which is the female reproductive structure of a flower. Here is a detailed explanation of each part of the carpel and why anther is not included:
1. Stigma: The stigma is the sticky, receptive surface located at the top of the carpel. It is responsible for receiving pollen during pollination.
2. Ovary: The ovary is the enlarged basal part of the carpel. It contains ovules, which are the female reproductive cells. After pollination, the ovary develops into a fruit and protects the developing seeds.
3. Style: The style is a slender, elongated structure that connects the stigma to the ovary. It provides a pathway for the pollen tubes to grow and deliver the pollen to the ovules.
4. Anther: The anther, on the other hand, is a part of the stamen, which is the male reproductive structure of a flower. The anther produces pollen grains that contain the male reproductive cells.
In summary, while the stigma, ovary, and style are all parts of the carpel, the anther belongs to the stamen and is not a part of the carpel.