How Do Organisms Reproduce? - Practice Test, Class 10 Science - Class 10 MCQ

Answer:
The information source for making proteins is DNA. Here is a detailed explanation:
DNA (Deoxyribonucleic Acid)
- DNA is a molecule found in the nucleus of cells and contains the genetic instructions for the development and functioning of all living organisms.
- It consists of a sequence of nucleotides that form a double helix structure.
- The sequence of nucleotides in DNA determines the sequence of amino acids in proteins, which are essential for the structure and function of cells.
- DNA serves as the template or blueprint for protein synthesis.
Protein Synthesis
- Protein synthesis is the process by which cells build proteins.
- It involves two main stages: transcription and translation.
- In transcription, a segment of DNA is copied into a molecule called messenger RNA (mRNA) by an enzyme called RNA polymerase.
- The mRNA carries the genetic information from the DNA to the ribosomes, where protein synthesis takes place.
- In translation, the mRNA is read by ribosomes, and the information is used to assemble the amino acids in the correct sequence to form a protein molecule.
Importance of Proteins
- Proteins are essential for the structure, function, and regulation of cells and tissues.
- They play a role in various biological processes, such as enzymatic reactions, cell signaling, transport of molecules, and immune responses.
- Different proteins have different functions and are involved in maintaining the overall health and functioning of an organism.
In conclusion, DNA is the information source for making proteins. It provides the genetic instructions that guide the synthesis of proteins through the processes of transcription and translation. Proteins are vital for the structure and function of cells and are essential for the overall well-being of living organisms.

The Embryo and Nutrition from the Mother's Blood
The embryo, during its development in the mother's womb, obtains nutrition through a specialized tissue known as the placenta. The placenta plays a crucial role in facilitating the exchange of nutrients, gases, and waste products between the mother and the developing embryo.
Explanation:
The placenta is a temporary organ that develops in the uterus during pregnancy. It is formed by both maternal and embryonic tissues and acts as a vital interface between the mother and the developing fetus.
Key Points:
- The placenta develops from the fertilized egg, specifically from the outer layer of cells called the trophoblast.
- It attaches to the uterine wall and establishes a connection with the mother's blood vessels, creating a network of blood vessels within the placenta.
- The mother's blood flows through these blood vessels, while the fetal blood flows through the umbilical cord, which is connected to the placenta.
- The placenta acts as a barrier between the mother's blood and the fetal blood, preventing them from mixing directly.
- Nutrients, oxygen, and hormones from the mother's blood are transported across the placenta to the embryo, providing it with the necessary nourishment for growth and development.
- Waste products, such as carbon dioxide and urea, produced by the embryo are transported back to the mother's blood through the placenta for elimination.
- The placenta also serves as a protective barrier, filtering out harmful substances and pathogens that could potentially harm the developing embryo.
- It plays a crucial role in maintaining the hormonal balance necessary for a healthy pregnancy and supports the production of hormones such as progesterone and estrogen.
- The placenta continues to grow and develop throughout pregnancy, adapting to the changing needs of the developing fetus.
- After birth, the placenta is expelled from the mother's body during the process of childbirth.
In conclusion, the placenta is the specialized tissue that allows the embryo to obtain nutrition from the mother's blood during pregnancy. It acts as an interface for the exchange of nutrients, gases, and waste products, ensuring the proper growth and development of the embryo.

Asexual reproduction through budding in yeast
Introduction:
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes. Budding is a common form of asexual reproduction in which a new organism develops as an outgrowth or bud from the parent organism.
Explanation:
In the given options, the organism that undergoes asexual reproduction through budding is yeast.
Yeast:
- Yeast is a unicellular fungus that reproduces asexually through budding.
- Budding in yeast involves the formation of a small bud or outgrowth on the parent cell.
- The bud grows in size and eventually detaches from the parent cell to become a new individual.
- This process allows yeast to rapidly reproduce and colonize new environments.
Other options:
Although the other options listed (amoeba, plasmodium, and leishmania) are also capable of asexual reproduction, they do not reproduce through budding.
- Amoeba reproduces asexually through binary fission, where the parent cell divides into two identical daughter cells.
- Plasmodium, the causative agent of malaria, reproduces asexually through multiple fission, where the parent cell divides into multiple daughter cells.
- Leishmania, a parasitic protozoan, reproduces asexually through binary fission or by dividing into multiple daughter cells.
Conclusion:
In summary, asexual reproduction through budding occurs in yeast. The other options listed do not undergo budding for asexual reproduction.

The Female Reproductive System
The female reproductive system is a complex system responsible for the production of eggs, fertilization, and the development and nourishment of a fetus. It consists of several organs and structures that work together to facilitate reproduction.
Organs of the Female Reproductive System
1. Ovary: The ovaries are the primary reproductive organs in females. They produce eggs (ova) and secrete hormones such as estrogen and progesterone.
2. Uterus: The uterus, or womb, is a muscular organ where a fertilized egg implants and develops into a fetus. It provides a nourishing environment for the growing embryo or fetus throughout pregnancy.
3. Fallopian tubes: Also known as oviducts, the fallopian tubes are a pair of long, slender tubes that connect the ovaries to the uterus. They provide a pathway for the egg to travel from the ovary to the uterus and are the site of fertilization.
Structure Not Part of the Female Reproductive System
4. Vas deferens: The vas deferens is a tube that carries sperm from the testes to the urethra in males. It is not a part of the female reproductive system.
In summary, the vas deferens is not a part of the female reproductive system. It is a structure found in males that is responsible for transporting sperm. The female reproductive system includes the ovaries, uterus, and fallopian tubes, which play crucial roles in the production and transport of eggs, fertilization, and pregnancy.

Binary fission in some organisms occurs in definite orientation in relation to the cell structures. One such organism is:
Answer: C. Amoeba
Explanation:
Amoeba is an example of an organism that undergoes binary fission in a definite orientation in relation to the cell structures. Here's a detailed explanation:
1. Binary fission: Binary fission is a form of asexual reproduction in which a single organism divides into two identical daughter cells.
2. Definite orientation: In some organisms, binary fission occurs in a specific orientation in relation to the cell structures. This means that the division plane is predetermined and aligned with certain cell structures.
3. Amoeba: Amoeba is a unicellular organism belonging to the phylum Protozoa. It is characterized by its flexible body shape and the absence of a fixed cell wall.
4. Cell structures in Amoeba: Amoeba has various cell structures, such as the nucleus, cytoplasm, and cell membrane.
5. Orientation of binary fission in Amoeba: During binary fission in Amoeba, the division plane is aligned with the cell structures. The nucleus divides first, followed by the cytoplasm, resulting in the formation of two daughter cells.
6. Significance of orientation: The definite orientation of binary fission in Amoeba ensures the proper distribution of cellular components and genetic material between the daughter cells.
7. Other examples: While Amoeba is one example of an organism that exhibits definite orientation in binary fission, it is important to note that there are other organisms as well, such as certain bacteria and some protists, that also undergo binary fission in a specific orientation.
In conclusion, Amoeba is an example of an organism that undergoes binary fission in a definite orientation in relation to the cell structures. This ensures proper division and distribution of cellular components between the daughter cells.

Plants that have lost their capacity to produce seeds, reproduce by vegetative propagation.
Explanation:
Vegetative propagation is a form of asexual reproduction in plants where new individuals are produced from vegetative parts of the parent plant. This method is employed by plants that have lost their ability to produce seeds. Here's a detailed explanation of how vegetative propagation works:
1. Definition:
Vegetative propagation involves the production of new individuals from vegetative structures such as stems, roots, or leaves, without the involvement of reproductive organs or seeds.
2. Types of Vegetative Propagation:
- Stem cuttings: A portion of the stem is cut from the parent plant and placed in a suitable medium to develop roots and eventually grow into a new plant.
- Root cuttings: A section of the root system is cut and planted in the soil, where it develops new shoots and roots to form a new plant.
- Leaf cuttings: A leaf or a portion of a leaf is used to generate new plants through the development of adventitious roots and shoots.
- Layering: A branch or stem of the parent plant is bent or partially buried in the soil, and roots develop at the point of contact with the soil. Once sufficient roots have formed, the stem can be separated from the parent plant and become an independent individual.
- Grafting and budding: These techniques involve joining a desired plant part (scion) with a rooted plant (rootstock) to create a new individual. This method is commonly used in fruit tree propagation.
3. Advantages of Vegetative Propagation:
- It allows for the rapid and efficient production of genetically identical offspring.
- It ensures the preservation of desired traits and characteristics of the parent plant.
- It bypasses the need for seed germination and reduces the time required for the new plant to reach maturity.
4. Examples of Plants that Use Vegetative Propagation:
- Potato plants can be propagated by planting sections of tubers.
- Strawberry plants produce runners that develop new plantlets at the nodes.
- Succulent plants, such as cacti, can be propagated from stem cuttings.
- Many ornamental plants, including roses and lavender, can be propagated through stem cuttings or layering.
In conclusion, plants that have lost their ability to produce seeds rely on vegetative propagation to reproduce. This method allows them to create new individuals using various vegetative structures without the need for sexual reproduction or seed formation.

Parts of a Stamen
There are two main parts of a stamen, which are:
1. Anther: The anther is the top part of the stamen and is responsible for producing and releasing pollen. It is usually located at the tip of the filament.
2. Filament: The filament is the long, slender stalk that supports the anther. Its main function is to position the anther in a way that ensures efficient pollen dispersal.
Explanation
The stamen is the male reproductive organ of a flower, and it plays a crucial role in the process of pollination. It produces and releases pollen, which is necessary for fertilization to occur. The two parts of the stamen, the anther and the filament, work together to carry out this important function.
- The anther is responsible for producing the pollen grains. These grains contain the male gametes (sperm cells) that are needed for fertilization. The anther is typically made up of four lobes, each containing pollen sacs.
- The filament supports the anther and positions it in a way that maximizes the chances of pollen dispersal. It is usually long and slender, allowing the anther to be positioned above the other parts of the flower, making it more accessible to pollinators.
Together, the anther and filament form the stamen, which is an essential part of the reproductive system of flowering plants. The stamen is typically located in the center of the flower, surrounded by the female reproductive organ called the pistil or carpel.
In conclusion, the correct answer is B: Anther and filament. These two parts of the stamen work together to ensure the production and dispersal of pollen, which is crucial for the fertilization of plants.

Biological Explanation:
A bisexual flower contains both stamens and carpels.
Stamens and carpels are the reproductive organs of a flower. Bisexual flowers, also known as perfect flowers, have both male and female reproductive structures. Here's a detailed explanation:
Stamens:
- Stamens are the male reproductive organs of a flower.
- Each stamen consists of a filament and an anther.
- The filament is a long, slender structure that holds the anther.
- The anther contains pollen grains, which are responsible for male gamete production (sperm cells).
Carpels:
- Carpels are the female reproductive organs of a flower.
- Each carpel consists of an ovary, a style, and a stigma.
- The ovary contains ovules, which are responsible for female gamete production (egg cells).
- The style is a slender tube that connects the ovary to the stigma.
- The stigma is a sticky surface that receives pollen grains during pollination.
Bisexual Flowers:
- Bisexual flowers contain both stamens and carpels in the same flower.
- This allows for self-pollination, where pollen from the stamens can fertilize the ovules in the same flower.
- It also enables cross-pollination, where pollen from one flower can be transferred to the stigma of another flower.
Function:
- The presence of both stamens and carpels in a bisexual flower ensures reproductive success through self-pollination or cross-pollination.
- This increases the chances of fertilization and the production of viable seeds.
- The ability to reproduce both sexually (cross-pollination) and asexually (self-pollination) provides flexibility and adaptability for the plant species.
In conclusion, a bisexual flower contains both stamens and carpels, enabling it to reproduce through self-pollination or cross-pollination. The presence of these reproductive organs ensures the successful production of seeds for the plant's survival and propagation.

The anther contains:
- Pollen grains: The main component found in the anther of a flower are pollen grains. These are small, powdery structures that contain the male reproductive cells of the flower. They are essential for the process of pollination, where the pollen grains are transferred from the anther to the stigma of a flower, allowing for fertilization and the production of seeds.

Explanation:
- Anther: The anther is part of the male reproductive organ of a flower known as the stamen. It is typically located at the top of the stamen and consists of two lobes or sacs called microsporangia, where the pollen grains are produced.
- Pollen grains: The pollen grains are the male gametophytes of a flower. Each pollen grain contains two cells - a generative cell and a tube cell. The generative cell will eventually divide to form two sperm cells, while the tube cell will elongate to form a pollen tube that will deliver the sperm cells to the ovule.
- Function: The anther is responsible for producing and releasing pollen grains into the environment. These pollen grains are then dispersed by wind, water, insects, birds, or other animals to reach the stigma of another flower, a process known as pollination. Once the pollen grains land on a receptive stigma, they germinate and form a pollen tube that grows down through the style to reach the ovule. This allows for the fertilization of the ovule and the development of seeds.

Feature of Reproduction in Amoeba, Spirogyra, and Yeast:
1. Asexual Reproduction:
- All three organisms, Amoeba, Spirogyra, and Yeast, are capable of reproducing asexually.
- Asexual reproduction involves the production of offspring without the involvement of gametes or the fusion of genetic material from two parents.
- It results in the production of genetically identical offspring, also known as clones.
2. Unicellular Nature:
- Another common feature among Amoeba, Spirogyra, and Yeast is that they are all unicellular organisms.
- Unicellular organisms consist of a single cell that carries out all the necessary functions of life.
- Despite their different shapes and structures, all three organisms exist as single cells.
3. Varied Asexual Reproductive Methods:
- Amoeba reproduces asexually through a process called binary fission, where the parent cell divides into two daughter cells.
- Spirogyra reproduces asexually through fragmentation, where a filament breaks into small fragments, each of which grows into a new organism.
- Yeast reproduces asexually through budding, where a small bud or outgrowth forms on the parent cell and eventually separates to become an individual organism.
Conclusion:
- The common feature of reproduction among Amoeba, Spirogyra, and Yeast is that they all reproduce asexually.
- Additionally, they are all unicellular organisms, with Amoeba and Spirogyra belonging to the Protista kingdom and Yeast belonging to the Fungi kingdom.

Which flower ripens to form a fruit?
Answer: B. Ovary
Explanation:
The flower is the reproductive structure of angiosperms (flowering plants). It consists of several parts, including the ovule, ovary, carpel, and egg cell. However, it is the ovary that ripens to form a fruit. Here's a detailed explanation:
1. Ovary: The ovary is the enlarged basal part of the carpel, located at the base of the flower. It contains one or more ovules, which are the structures that develop into seeds after fertilization.
2. Fertilization: After pollination, when pollen grains reach the stigma and travel down the style, they fertilize the ovules inside the ovary. This process involves the fusion of the male gametes (sperm) with the female gametes (egg cells) within the ovule.
3. Seed Development: Once fertilization occurs, the ovules begin to develop into seeds. The fertilized ovule contains an embryo, which grows and develops within the protective seed coat.
4. Fruit Formation: As the seeds develop, the ovary undergoes changes and starts to ripen. The ovary wall becomes fleshy or firm, depending on the type of fruit. This ripening process is triggered by hormones and is accompanied by various biochemical changes.
5. Maturation: The ripening of the ovary is a sign of maturation for the flower. The mature ovary, now transformed into a fruit, protects the seeds and aids in their dispersal. Fruits can have different shapes, sizes, colors, and textures, depending on the plant species.
In conclusion, the ovary is the part of the flower that ripens to form a fruit. It plays a crucial role in protecting and dispersing the seeds produced through fertilization.

The Functions of the Testes:
There are several important functions that the testes perform in males. These include:
1. Production of Testosterone:
- Testosterone is the primary male sex hormone that plays a crucial role in the development and maintenance of male reproductive tissues and secondary sexual characteristics.
- It is responsible for the development of the male reproductive organs, such as the penis and scrotum, as well as the growth of facial and body hair.
- Testosterone also promotes the growth of muscle mass and bone density, and is involved in regulating libido and mood.
2. Production of Sperm:
- Sperm production, also known as spermatogenesis, occurs within the testes.
- The testes contain structures called seminiferous tubules, where sperm cells are produced.
- Spermatogenesis involves the process of cell division, differentiation, and maturation to produce mature sperm cells capable of fertilizing an egg.
3. Production of Male Gametes and Hormones:
- The testes produce male gametes, which are the sperm cells responsible for fertilizing the female egg.
- In addition to sperm production, the testes also produce male hormones, including testosterone.
- These hormones are essential for the proper functioning of the male reproductive system and the development of secondary sexual characteristics.
4. No Involvement in Urine Production:
- The testes are not involved in urine production.
- Urine is produced by the kidneys and excreted through the urinary system, which includes the bladder, ureters, and urethra.
Therefore, the correct answer is option C: The testes produce male gametes and hormones.

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

• Mechanical Method: Condoms are a form of contraception that falls under the mechanical method category of birth control. This method involves the use of physical barriers to prevent sperm from reaching the egg.


• Barrier Method: Condoms act as a physical barrier between the penis and the vagina, preventing sperm from entering the woman's reproductive system. They are designed to collect semen and prevent it from reaching the cervix, where fertilization can occur.


• Prevention of Pregnancy and STIs: Condoms are highly effective in preventing pregnancy when used correctly and consistently. They are also one of the most effective methods of preventing the transmission of sexually transmitted infections (STIs) such as HIV, chlamydia, gonorrhea, and syphilis.


• Easy to Use: Condoms are widely available and easy to use. They can be purchased without a prescription and are relatively inexpensive. They are also convenient as they can be carried and used at any time.


• Non-Hormonal: Unlike hormonal methods of contraception, condoms do not introduce any hormones into the body. This makes them a suitable option for individuals who cannot or do not wish to use hormonal contraception.

In conclusion, condoms are a mechanical method of birth control that provides both pregnancy prevention and protection against STIs. They are a popular and effective choice for individuals who want a non-hormonal method of contraception.

The common passage for sperms and urine in the male reproductive system is the Urethra.
Explanation:
The male reproductive system is responsible for producing and delivering sperm for fertilization. It also plays a role in the elimination of urine from the body. The common passage for both sperms and urine is the urethra, which is a tube that connects the urinary bladder to the external opening of the penis.
Key Points:
- The urethra is a tube that serves as a passage for both sperms and urine in the male reproductive system.
- It starts from the urinary bladder and extends through the penis.
- The urethra has two main functions: to transport urine from the bladder to the outside of the body and to transport sperm during ejaculation.
- During urination, the urinary sphincter relaxes, allowing urine to flow through the urethra and out of the body.
- During ejaculation, the reproductive glands (such as the prostate gland and seminal vesicles) release fluids into the urethra, which mix with the sperm to form semen.
- The urethra acts as a conduit for semen to be expelled from the body during ejaculation.
Therefore, the correct answer is C: Urethra.

Mitochondria in Sperm
Introduction:
Mitochondria are the energy-producing organelles found in cells. They play a vital role in producing adenosine triphosphate (ATP), which is the main source of energy for cellular processes. In sperm, mitochondria are located in a specific region known as the middle piece.
Location of Mitochondria in Sperm:
The mitochondria in sperm are located in the middle piece, which is a region connecting the head and the tail of the sperm. This region contains a high density of mitochondria to provide the necessary energy for the sperm to swim and reach the egg for fertilization.
Function of Mitochondria in Sperm:
The mitochondria in the middle piece of sperm serve several important functions, including:
1. ATP Production: Mitochondria generate ATP through oxidative phosphorylation, which is essential for powering the movement of the sperm's tail (flagellum). This ATP production helps in the swimming ability of sperm, enabling them to reach and penetrate the egg.
2. Maintenance of Sperm Viability: The mitochondria in the middle piece also help in maintaining the viability and functionality of the sperm. They provide the necessary energy for various cellular processes, including the capacitation process, which is essential for sperm maturation and fertilization.
3. DNA Replication and Repair: Mitochondria contain their own DNA, known as mitochondrial DNA (mtDNA). These DNA molecules replicate and repair within the mitochondria, ensuring the integrity and functionality of the organelle. This is crucial for the overall health and functionality of the sperm.
Conclusion:
In conclusion, mitochondria in sperm are mainly located in the middle piece, which connects the head and the tail. They play a crucial role in ATP production, maintenance of sperm viability, and DNA replication and repair. The presence of mitochondria in the middle piece ensures that the sperm has sufficient energy for swimming and fertilization processes.

Chlamydiosis is related to the Urethra. Here is a detailed explanation of the relationship between chlamydiosis and the urethra:
Chlamydiosis:
- Chlamydiosis is a sexually transmitted infection caused by the bacterium Chlamydia trachomatis. It can affect both men and women.
- It is one of the most common sexually transmitted infections globally, with millions of cases reported each year.
The Urethra:
- The urethra is a tube that carries urine from the bladder out of the body. In males, it also serves as the passage for semen during ejaculation.
Relationship between Chlamydiosis and the Urethra:
- Chlamydia trachomatis can infect the urethra when a person engages in sexual activities with an infected partner.
- The bacteria can enter the urethra during unprotected vaginal, anal, or oral sex.
- Once inside the urethra, the bacteria can cause inflammation and infection, resulting in a condition known as urethritis.
Urethritis:
- Urethritis is the inflammation of the urethra, which can be caused by various pathogens, including Chlamydia trachomatis.
- Symptoms of urethritis may include pain or burning during urination, frequent urination, discharge from the urethra, and in some cases, blood in the urine.
Testing and Treatment:
- Testing for chlamydiosis involves collecting a urine sample or swabbing the urethra to detect the presence of Chlamydia trachomatis.
- If diagnosed with chlamydiosis, treatment usually involves a course of antibiotics to clear the infection.
- It is important to complete the full course of antibiotics as prescribed, even if symptoms improve, to ensure the infection is completely eradicated.
In conclusion, chlamydiosis is related to the urethra because the bacteria Chlamydia trachomatis can infect the urethra, leading to urethritis. Testing and prompt treatment are essential to manage and prevent further spread of the infection.

The General Definition of a Fruit:

A fruit is generally defined as a mature ovary of a flowering plant. This means that after a flower is pollinated, the ovary undergoes maturation and develops into a fruit.
Detailed Explanation:

Here is a breakdown of the options provided and why the correct answer is C: a mature ovary.
A: a thickened style:
- The style is a part of the female reproductive organ in a flower.
- It is responsible for connecting the stigma to the ovary.
- While the style may undergo changes during fertilization, it does not define a fruit.
B: an enlarged ovule:
- An ovule is a structure found within the ovary.
- It contains the potential to become a seed after fertilization.
- While the ovule is involved in fruit development, it does not represent the entire fruit itself.
C: a mature ovary:
- The ovary is the part of the flower that encloses and protects the ovules.
- After fertilization, the ovary undergoes transformation and becomes the fruit.
- The fruit contains the mature seeds derived from the fertilized ovules.
- This definition accurately describes a fruit.
D: a modified root:
- A fruit is not a modified root.
- Roots are typically involved in nutrient absorption and anchoring the plant, not fruit production.
Therefore, the correct answer is C: a mature ovary, as it accurately represents the general definition of a fruit.

The vegetative propagation in sweet potato is by the root.
Vegetative propagation refers to the process of reproducing plants asexually using vegetative parts of the plant, such as stems, roots, or leaves. In the case of sweet potatoes, the primary method of vegetative propagation is through the use of the root.
Here are the reasons why vegetative propagation in sweet potato is done through the root:
1. Formation of adventitious roots: Sweet potato plants have the ability to form adventitious roots, which are roots that develop from non-root tissues. These adventitious roots arise from nodes or buds on the sweet potato root.
2. Storage of nutrients: Sweet potato roots are modified storage organs that contain a significant amount of nutrients. This makes them ideal for vegetative propagation as the stored nutrients can support the growth of new shoots and leaves, ensuring the survival of the new plant.
3. Ability to produce multiple shoots: When a sweet potato root is planted, it has the capacity to produce multiple shoots. Each shoot can develop into a new sweet potato plant, resulting in the propagation of the plant.
4. Ease of handling: Sweet potato roots are relatively easy to handle and propagate. They can be cut into sections, each containing a bud or node, and planted separately to give rise to new plants.
5. Genetic uniformity: Vegetative propagation through the root ensures genetic uniformity in the propagated plants, as they are essentially clones of the parent plant. This can be advantageous for maintaining desirable traits in sweet potato varieties.
In conclusion, vegetative propagation in sweet potato is primarily done through the root due to the formation of adventitious roots, the storage of nutrients, the ability to produce multiple shoots, ease of handling, and the maintenance of genetic uniformity.

Vegetative Propagation in Bryophyllum
Vegetative propagation is a method of asexual reproduction in plants where new individuals are produced from vegetative parts of the parent plant. In the case of Bryophyllum, vegetative propagation occurs through the leaves.
Explanation:
The process of vegetative propagation in Bryophyllum involves the following steps:
1. Formation of plantlets: Bryophyllum plants have specialized leaves with small plantlets present along the margins. These plantlets are capable of developing into new individuals.
2. Leaf detachment: When the plantlets are fully developed, they become detached from the parent leaf and fall to the ground or other suitable substrates.
3. Root formation: Once the plantlet comes in contact with the soil or a suitable substrate, it develops roots from its base. These roots anchor the plantlet and facilitate the uptake of water and nutrients.
4. Growth and development: With the presence of roots, the plantlet starts to grow and develop into a mature Bryophyllum plant. It gradually develops new leaves, stems, and flowers, continuing the life cycle.
Therefore, the correct answer is C: leaf as vegetative propagation in Bryophyllum occurs through the formation of plantlets on the leaves.

Multiple Fission in Plasmodium
Plasmodium is a unicellular parasite that causes malaria in humans. It undergoes multiple fission as part of its life cycle.
Explanation:
Multiple fission is a type of asexual reproduction in which a single organism divides into multiple daughter cells simultaneously. Here's how multiple fission occurs in Plasmodium:
1. Formation of Sporozoites: Plasmodium undergoes sexual reproduction in the mosquito host, resulting in the formation of sporozoites. These sporozoites migrate to the salivary glands of the mosquito.
2. Bite of an Infected Mosquito: When an infected mosquito bites a human, it injects the sporozoites into the bloodstream.
3. Invasion of Liver Cells: The sporozoites travel to the liver and invade liver cells (hepatocytes).
4. Formation of Merozoites: Inside the hepatocytes, the sporozoites undergo multiple fission to produce thousands of merozoites. These merozoites are released into the bloodstream.
5. Invasion of Red Blood Cells: The merozoites invade red blood cells (erythrocytes) and undergo further multiplication.
6. Formation of Gametocytes: Some merozoites develop into male and female gametocytes, which are the sexual forms of Plasmodium.
7. Transmission to Mosquito: When a mosquito bites an infected human, it ingests the gametocytes along with the blood.
8. Formation of Zygote and Oocyst: In the mosquito's gut, the male and female gametocytes fuse to form a zygote. The zygote develops into an oocyst.
9. Multiple Fission in Oocyst: The oocyst undergoes multiple fission, producing thousands of sporozoites.
10. Migration to Salivary Glands: The sporozoites migrate to the mosquito's salivary glands, ready to infect another human during a subsequent bite.
Therefore, multiple fission is seen in Plasmodium during its life cycle, specifically during the formation of merozoites in liver cells and sporozoites in the mosquito's oocyst.

Progesterone is secreted by the Corpus luteum.
The detailed explanation is as follows:
Corpus luteum:
- The Corpus luteum is a temporary endocrine structure that develops from the ovarian follicle after ovulation.
- It forms in the ovary at the site where the egg was released.
- The Corpus luteum is responsible for the production and secretion of progesterone.
- It plays a crucial role in preparing the uterus for implantation and maintaining pregnancy.
- Progesterone helps in thickening the uterine lining, making it suitable for the implantation of a fertilized egg.
- If pregnancy does not occur, the Corpus luteum degenerates and becomes the Corpus albicans.
- However, if fertilization occurs, the Corpus luteum continues to produce progesterone until the placenta takes over its role.
In summary, the Corpus luteum is the structure responsible for the secretion of progesterone in the female reproductive system.

Unequal daughter cells are produced in budding.
Explanation:
Budding is a form of asexual reproduction in which a new organism develops as an outgrowth or bud from the parent organism. During the process of budding, unequal daughter cells are produced.
Here is a detailed explanation of how unequal daughter cells are produced in budding:
1. Formation of a bud:
- The process of budding begins with the formation of a bud on the parent organism.
- The bud is an outgrowth that develops from the parent organism's body.
2. Unequal distribution of cytoplasm:
- As the bud grows, cytoplasm from the parent organism is unequally distributed into the bud.
- This results in one daughter cell receiving more cytoplasm than the other.
3. Nucleus division:
- The nucleus of the parent organism also undergoes division.
- The divided nucleus is then unequally distributed into the two daughter cells.
4. Growth and detachment:
- The bud continues to grow and eventually detaches from the parent organism.
- The daughter cell that received more cytoplasm and nucleus develops into a new organism, while the other daughter cell may remain as a smaller, dormant structure or eventually degenerate.
5. Examples of budding:
- Budding is commonly observed in organisms like yeast, hydra, and some types of plants.
In conclusion, the process of budding results in the production of unequal daughter cells, where one cell receives more cytoplasm and nucleus than the other.