Life Cycle Of Angiosperms MCQ Test - Reproduction In Plants, Botany, Class 12 - Class 12 MCQ

Most reduced size gametophyte is of Angiosperm
Explanation:
The gametophyte is the haploid phase in the life cycle of plants, and it is responsible for producing gametes (reproductive cells). In most plants, the gametophyte is reduced in size compared to the sporophyte (diploid phase), which is the dominant phase in the life cycle.
Among the options given, the most reduced size gametophyte is found in Angiosperms (flowering plants). Here's why:
1. Bryophytes:
- Bryophytes, such as mosses, liverworts, and hornworts, have a dominant gametophyte phase.
- The gametophyte is larger and more complex compared to the sporophyte in bryophytes.
2. Pteridophytes:
- Pteridophytes, including ferns, have a dominant sporophyte phase.
- The gametophyte in pteridophytes, known as a prothallus, is larger than that of angiosperms but still relatively larger compared to the sporophyte.
3. Gymnosperms:
- Gymnosperms, such as conifers and cycads, have a dominant sporophyte phase.
- The gametophyte in gymnosperms is reduced in size compared to pteridophytes but not as small as the gametophyte of angiosperms.
4. Angiosperms:
- Angiosperms have a dominant sporophyte phase, which is the flowering plant we are most familiar with.
- The gametophyte in angiosperms is highly reduced in size and is often microscopic.
- In most angiosperms, the male gametophyte (pollen grain) consists of only three cells, while the female gametophyte (embryo sac) consists of only seven cells.
Therefore, the most reduced size gametophyte is found in Angiosperms (option D).

Explanation:
The given question is about the pollen grain of Capsella and its classification based on the number of colpi (furrows) present on the surface of the grain.
Key Points:
- Pollen grains are the male reproductive structures of flowering plants.
- The number and arrangement of colpi on the pollen grain's surface are important characteristics used for classification.
- Monocolpate pollen grains have a single furrow or colpus.
- Bicolpate pollen grains have two furrows or colpi.
- Tricolpate pollen grains have three furrows or colpi.
- Polycolpate pollen grains have multiple furrows or colpi.

Based on the given information, we can determine the classification of the pollen grain of Capsella.
- The answer is Tricolpate (C) because the pollen grain of Capsella has three furrows or colpi on its surface.
Thus, the correct answer is c. Tricolpate.

Essential whorls of a flower:
There are three essential whorls of a flower, which are the reproductive parts of the flower. These whorls include:
1. Androecium:
- The androecium is the male reproductive part of the flower.
- It consists of the stamens, which are composed of the filament and anther.
- The anther produces pollen grains, which contain the male gametes.
2. Gynoecium:
- The gynoecium is the female reproductive part of the flower.
- It consists of the pistil, which is composed of the stigma, style, and ovary.
- The stigma receives pollen grains, the style connects the stigma to the ovary, and the ovary contains the female gametes.
3. Calyx and Corolla:
- The calyx and corolla are the non-reproductive parts of the flower.
- The calyx is the outermost whorl and consists of sepals, which are usually green and protect the flower in bud.
- The corolla is the inner whorl and consists of petals, which are often colorful and attract pollinators.
Answer: C. Androecium and Gynoecium

Answer:
Filiform pollen grains are found in the following plants:
- Calotropis: Calotropis is a genus of flowering plants in the milkweed family. The plants in this genus produce filiform pollen grains.
- Myosotis: Myosotis, commonly known as forget-me-not, is a genus of flowering plants. Some species in this genus produce filiform pollen grains.
- Cyperus: Cyperus is a large genus of sedges, commonly known as nutsedges. Some species in this genus produce filiform pollen grains.
- Zostera: Zostera is a genus of marine flowering plants, commonly known as seagrasses. Some species in this genus produce filiform pollen grains.
Therefore, the correct answer is option D: Zostera.

Statement analysis:
The question asks to identify the false statement among the given options. Let's analyze each statement:
A: Unisexuality of flower induces cross-pollination
- Unisexuality refers to having separate male and female flowers on the same plant.
- Cross-pollination occurs when pollen from one flower is transferred to the stigma of another flower.
- Unisexuality can promote cross-pollination as it ensures that the male and female reproductive parts are present in separate flowers on the same plant, increasing the chances of outcrossing.
- This statement is true.
B: Androgenic plants are developed by Guha & Maheshwari
- Androgenesis is a process in which plants are developed from pollen grains without fertilization.
- Guha and Maheshwari were the first to successfully induce androgenesis in plants.
- This statement is true.
C: Morphological barriers are absent in Gloriosa flower
- Morphological barriers refer to physical structures that prevent or restrict pollination between different species or individuals.
- Gloriosa is a genus of flowering plants that are known to have morphological barriers, such as the shape and structure of the floral parts, which restrict pollination to specific pollinators.
- This statement is false.
D: All
- This option suggests that all the statements are false, which is not the case as statement A and statement B are true.
Conclusion:
Among the given statements, statement C is false. Morphological barriers are present in Gloriosa flowers, contrary to what is stated in the statement.

Isobilateral Tetrad in Plants
Isobilateral tetrad is a term used to describe the arrangement of cells in a tetrad where all the four cells are similar in shape and size. This type of arrangement is commonly found in certain plants. Let's explore the options given in the question and determine which one is correct.
A: Monocots
Monocots are a type of flowering plants that have a single cotyledon (seed leaf) in their embryos. They include plants such as grasses, lilies, orchids, and palms. Isobilateral tetrad is common in monocots, making option A a possible answer.
B: Dicots
Dicots, also known as eudicots, are a type of flowering plants that have two cotyledons in their embryos. They include plants such as roses, sunflowers, beans, and tomatoes. Isobilateral tetrad is not commonly found in dicots, so option B is not correct.
C: Halophia
Halophia is not a recognized scientific term or a specific group of plants. Therefore, option C is not a valid answer.
D: None of the Above
Based on the information provided, the correct answer is option A: Monocots. Isobilateral tetrad is common in monocots, which have a single cotyledon in their embryos.
In conclusion, isobilateral tetrad is commonly found in monocots. This arrangement of cells is not typically observed in dicots or any specific plant group called Halophia.

Tetrad Types in Magnolia Plant:
Magnolia plants exhibit a specific type of arrangement of leaves known as a tetrad. A tetrad is a pattern in which four leaves are arranged around a stem, forming a cross-like shape. There are different types of tetrad arrangements found in plants, and the type of tetrad found in Magnolia plants is the decussate tetrad. Here are the details:
1. Isobilateral:
- Isobilateral tetrad refers to a leaf arrangement where all four leaves are oriented in the same plane.
- In this type, the upper and lower surfaces of the leaves are similar, and the midrib is located in the center.
- Isobilateral tetrad is not found in Magnolia plants.
2. T-shaped:
- T-shaped tetrad refers to a leaf arrangement where two opposite leaves are positioned horizontally, and the other two leaves are placed vertically.
- This type of tetrad is not found in Magnolia plants.
3. Linear:
- Linear tetrad refers to a leaf arrangement where four leaves are arranged in a linear manner along the stem.
- This type of tetrad is not found in Magnolia plants.
4. Decussate:
- Decussate tetrad refers to a leaf arrangement where two opposite leaves are positioned at a right angle to the next pair of opposite leaves.
- The leaves form a cross-like pattern, and each pair of leaves is perpendicular to the adjacent pair.
- This is the type of tetrad found in Magnolia plants.
In conclusion, the type of tetrad found in Magnolia plants is the decussate tetrad, where the leaves are arranged in a cross-like pattern.

Sporopollenin is found in:
- Exine: Sporopollenin is a major component of the exine, which is the outer layer of the pollen grain. It forms a tough and resistant layer that protects the pollen grain from various environmental factors.
- Intine: Sporopollenin is not found in the intine, which is the inner layer of the pollen grain. The intine is composed of cellulose and pectin and is involved in the growth and development of the pollen tube.
- Cytoplasm: Sporopollenin is not found in the cytoplasm of the pollen grain. The cytoplasm contains various organelles and is responsible for the metabolic activities of the cell.
- Nucleus: Sporopollenin is not found in the nucleus of the pollen grain. The nucleus contains genetic material and is involved in the control of cellular functions.
Therefore, the correct answer is A: Exine.

Microsporophyll of Angiosperms is known as:
The correct answer is D: Stamen.
Explanation:
The microsporophyll is a structure found in angiosperms, which are flowering plants. It is responsible for producing and holding the microspores, which eventually develop into pollen grains. The microsporophyll is an important part of the male reproductive system of angiosperms.
Here is a detailed explanation of the options given:
- A: Androecium: Androecium refers to the male reproductive part of a flower, which includes all the stamens. While the stamen is made up of a microsporophyll, the androecium is a collective term for all the stamens in a flower.
- B: Anther: The anther is the top part of the stamen, which contains the microsporangia. The microsporangia are responsible for producing the microspores, which develop into pollen grains. So, the anther is a part of the microsporophyll, but it is not the microsporophyll itself.
- C: Filament: The filament is the long, slender stalk that supports the anther. It does not produce or hold the microspores. It is the microsporophyll, specifically the anther, that is responsible for producing and holding the microspores.
- D: Stamen: The stamen is the male reproductive organ of a flower. It consists of the anther and the filament. The anther, as mentioned earlier, is the microsporophyll that produces and holds the microspores. Therefore, the stamen is the correct answer as it includes the microsporophyll.
In conclusion, the microsporophyll of angiosperms is known as the stamen, which consists of the anther and the filament. The anther is the specific part of the stamen that functions as the microsporophyll by producing and holding the microspores.

Main function of endothecium (in anther) is:
The endothecium is a tissue found in the anther of a flower. It plays a crucial role in the process of pollen development and release. The main functions of the endothecium are as follows:

Mechanical Function:
- The endothecium provides mechanical support to the anther.
- It helps in maintaining the structural integrity of the anther during pollen development and dehiscence.

Nutritive Function:
- The endothecium is involved in supplying nutrients to the developing pollen grains.
- It provides nourishment and energy required for pollen maturation.

Dehiscence:
- The endothecium is responsible for the dehiscence or the opening of the anther to release mature pollen grains.
- It undergoes specific changes in its cell walls, which allow for the controlled release of pollen.

None of the Above:
- The correct answer is not "None of the Above" as the endothecium has specific functions in the anther.
Overall, the endothecium has essential roles in providing mechanical support, supplying nutrients, and facilitating the dehiscence of the anther for pollen release.

Explanation:
A: Monothecousanthers are found in Malvaceae family
- This statement is correct. Monothecous anthers refer to anthers with a single chamber. They are found in the Malvaceae family, which includes plants like hibiscus and cotton.
B: Middle layer is ephemeral
- This statement is correct. The middle layer in the anther wall is ephemeral, meaning it is short-lived and degenerates during the development of the anther.
C: Amoeboid tapetum releases ubisch bodies
- This statement is incorrect. The amoeboid tapetum does not release ubisch bodies. Ubisch bodies are released by the glandular or secretory tapetum. The amoeboid tapetum provides nutrients to the developing pollen grains.
D: Banana is a monocarpic plant
- This statement is correct. Banana is a monocarpic plant, which means it flowers and produces fruits only once in its lifetime. After producing fruits, the plant dies and is replaced by new shoots.
Therefore, the correct answer is option C: Amoeboid tapetum releases ubisch bodies.

Development of male gametophyte is:
The development of male gametophyte in plants is a complex process that involves several stages. It can occur through different mechanisms, including in vivo and in situ development. Let's explore each of these mechanisms in detail:
In vivo development:
- In vivo development refers to the development of male gametophyte inside the anther of the flower.
- It involves a series of events starting from the formation of microspore mother cells through meiosis.
- The microspore mother cells undergo meiosis to produce haploid microspores.
- These microspores then undergo further development to form the male gametophyte, which includes the formation of pollen grains.
- The male gametophyte contains two haploid cells, the generative cell and the tube cell, enclosed within the pollen grain.
In situ development:
- In situ development refers to the development of male gametophyte within the pollen grain after it is released from the anther.
- The mature pollen grain contains the male gametophyte, which is already developed.
- Inside the pollen grain, the male gametophyte consists of three cells - the vegetative cell, generative cell, and the tube cell.
- The generative cell divides to form two sperm cells, which are necessary for double fertilization in angiosperms.
- The tube cell elongates and forms the pollen tube, which delivers the sperm cells to the female reproductive organ for fertilization.
Both in vivo and in situ development:
- Some plants exhibit both in vivo and in situ development of male gametophyte.
- In these plants, the male gametophyte initially develops inside the anther (in vivo) and then undergoes further development within the released pollen grain (in situ).
- This dual mechanism ensures the proper maturation and functionality of the male gametophyte.
Conclusion:
In summary, the development of male gametophyte can occur through in vivo, in situ, or both mechanisms. The specific mechanism may vary among different plant species. Understanding the development of male gametophyte is crucial for studying plant reproduction and breeding techniques.

Why are pollen grains preserved for a long time?

Sporopollenin:

• Sporopollenin is the main component of the outer wall of pollen grains.


• It is a highly resistant and durable polymer.


• It is chemically inert and resistant to decay, making it highly suitable for long-term preservation.

Other factors:

• Pollen grains are small and compact, which helps protect them from physical damage.


• They are often encapsulated within protective structures, such as the exine layer, which provides additional protection.


• Pollen grains are often dispersed into the environment, where they can become trapped in sediments or preserved in amber, ice, or other substances.


• These preservation environments can shield the pollen grains from environmental factors that could degrade or destroy them.

Conclusion:

The main reason why pollen grains are preserved for a long time is due to the presence of sporopollenin, a highly resistant and durable polymer that forms the outer wall of the grains. Additionally, the small size and protective structures of pollen grains, as well as their dispersal and preservation environments, contribute to their long-term preservation.

Explanation:
The anther is a part of the male reproductive organ in flowering plants that produces pollen. It consists of several layers, including the endothecium, middle layer, and tapetum. These layers are derived from different sources:
Endothecium:
- The endothecium is the innermost layer of the anther wall.
- It is derived from the primary parietal layer of the anther wall.
- The primary parietal layer is the outermost layer of the anther wall that surrounds the sporogenous tissue.
- Therefore, the endothecium is derived from the primary parietal layer.
Middle Layer:
- The middle layer is located between the endothecium and the tapetum.
- It is derived from the primary parietal layer of the anther wall.
- Therefore, the middle layer is also derived from the primary parietal layer.
Tapetum:
- The tapetum is the innermost layer of the anther wall, surrounding the pollen sacs.
- It is derived from the primary sporogenous layer of the anther wall.
- The primary sporogenous layer is the innermost layer of the anther wall that gives rise to the microspore mother cells, which eventually develop into pollen grains.
- Therefore, the tapetum is derived from the primary sporogenous layer.
Conclusion:
- The endothecium and middle layer in the anther are derived from the primary parietal layer.
- The tapetum in the anther is derived from the primary sporogenous layer.
- Therefore, the correct answer is B: Primary parietal layer.

Female Gametophyte
Explanation:
To identify the female gametophyte, we need to understand the structures involved in plant reproduction.
Plant Reproduction:
- Plant reproduction involves the formation of male and female gametes.
- Male gametes are produced in the anther of the flower, while female gametes are produced in the ovule.
Female Gametophyte:
- The female gametophyte is the structure that produces the female gametes (eggs) in plants.
- It is also known as the embryo sac.
Options:
A: Embryo - The embryo is the result of fertilization between the male and female gametes. It is not the female gametophyte.
B: Embryosac - This is the correct answer. The embryosac is the female gametophyte, which produces the female gametes.
C: Endosperm - The endosperm is a nutrient-rich tissue that provides nourishment to the developing embryo. It is not the female gametophyte.
D: Pistil - The pistil is the female reproductive organ of a flower. It consists of the stigma, style, and ovary. The ovary contains the ovules, which house the female gametophyte.
Conclusion:
The female gametophyte in plants is the embryosac. It is responsible for producing the female gametes (eggs) necessary for fertilization.

Answer:
The type of ovule found in Capsella is Campylotropous.
Explanation:
- Ovules are the structures that give rise to seeds in flowering plants.
- There are different types of ovules based on their orientation and position within the ovary.
- In Capsella, the ovules are Campylotropous.
- Campylotropous ovules have a curved or bent shape.
- They have a micropyle (opening) at one end and a funiculus (stalk) attached to the other end.
- The ovule is curved in such a way that the micropyle and funiculus are close to each other.
- This curved shape allows for efficient fertilization and seed development.
- Capsella, also known as shepherd's purse, is a genus of flowering plants in the mustard family (Brassicaceae).
- It is a small annual or biennial herb with triangular fruit pods.
- The ovules in Capsella are campylotropous, which is a characteristic feature of this plant species.
Therefore, the correct answer is B: Campylotropus.

Embryo sac of Capsella derives its nutrition from the Nucellus.
Explanation:
The embryo sac of Capsella, a flowering plant, obtains its nutrition from the nucellus, which is a part of the ovule. The nucellus is a nutritive tissue that surrounds and nourishes the developing embryo sac or megagametophyte.
The process of nutrition transfer in the embryo sac of Capsella occurs through the following steps:
1. Development of the embryo sac: The embryo sac is formed within the ovule during the process of megasporogenesis and megagametogenesis. It is a female gametophyte that contains the egg cell and other accessory cells.
2. Nutrition source: The nucellus, which is present in the ovule, acts as a nutrient source for the developing embryo sac. It provides essential nutrients and energy required for the growth and development of the embryo sac.
3. Transfer of nutrients: The nutrients present in the nucellus are transferred to the developing embryo sac through specialized cells called transfer cells. These transfer cells have an increased surface area and invaginations, which facilitate the efficient transfer of nutrients.
4. Nutritional support: The nutrients obtained from the nucellus support the metabolic activities and growth of the developing embryo sac. They are utilized for cell division, cell enlargement, and the synthesis of essential molecules.
In conclusion, the embryo sac of Capsella derives its nutrition from the nucellus, a nutritive tissue present in the ovule. The nutrients provided by the nucellus are crucial for the growth and development of the embryo sac.

Polygonum Type of Embryosac
The correct answer is A: 7-celled and 8-nucleate. Here's a detailed explanation:
Embryosac
- The embryosac is the female gametophyte in angiosperms, which develops within the ovule.
- It contains the egg cell, which is fertilized by the pollen to form the zygote and eventually the embryo.
Polygonum Type
- The Polygonum type of embryosac refers to a specific pattern of development observed in some angiosperms, including plants in the genus Polygonum.
- In the Polygonum type, the embryosac follows a specific cellular and nuclear division pattern.
Cellular and Nuclear Division Pattern
- In the Polygonum type of embryosac, the initial megaspore undergoes three rounds of nuclear division without cell division, resulting in eight nuclei within a single cell.
- These nuclei are arranged in a specific pattern within the cell.
Arrangement of Nuclei
- Within the embryosac, the eight nuclei are arranged as follows:
- Three nuclei are located at the micropylar end (near the opening of the ovule).
- Three nuclei are located at the chalazal end (opposite the micropyle).
- The remaining two nuclei are positioned in the center of the embryosac.
Cellular Organization
- While the embryosac contains eight nuclei, it is divided into seven cells due to cellular walls being formed.
- The seven cells are arranged as follows:
- Two synergids at the micropylar end.
- One egg cell located between the synergids.
- Three antipodal cells at the chalazal end.
- One central cell containing two polar nuclei.
Therefore, the correct answer is A: 7-celled and 8-nucleate, indicating that the embryosac in the Polygonum type is composed of seven cells and eight nuclei arranged in a specific pattern.

Type of Ovule in Mirabilis:
- Anatropous: Anatropous ovules have a straight raphe and the micropyle is located at the opposite end of the base. The ovule becomes completely inverted during development. The nucellus is curved, and the chalaza and micropyle are close together.
- Orthotropous: Orthotropous ovules have a straight raphe and the micropyle is located at the base, parallel to the funiculus. The ovule is straight and upright, with the nucellus positioned above the chalaza.
- Circinotropous: Circinotropous ovules are intermediate between anatropous and orthotropous. They have a curved raphe and the micropyle is located at the base, but not parallel to the funiculus. The ovule is slightly curved, with the nucellus positioned above the chalaza.
- None: The answer states that Mirabilis does not have a specific type of ovule. This could mean that Mirabilis has a unique or uncommon type of ovule not listed above, or it may not have an ovule at all.
Based on the given options and the answer provided, it can be concluded that Mirabilis does not have a specific type of ovule.

The functional megaspore in Capsella is always Chalazal.
Explanation:
- In Capsella, which is a genus of flowering plants, the functional megaspore is always chalazal.
- The chalaza is the base of the ovule where the integuments are fused together, and it is opposite the micropyle.
- The chalazal megaspore is the megaspore located near the chalaza.
- This megaspore undergoes megasporogenesis and develops into the female gametophyte or embryo sac.
- The embryo sac contains the egg cell, synergids, antipodal cells, and central cell with two polar nuclei.
- Fertilization occurs when the pollen tube reaches the embryo sac and delivers the sperm cells to the egg cell.
- Capsella plants have a chalazogamy mode of fertilization, where the pollen tube enters through the chalaza to reach the embryo sac.
- Therefore, the functional megaspore in Capsella is always chalazal.
Answer: B: Chalazal

Crassinucellate ovule shows:
- Well developed nucellus.
Explanation:
- Crassinucellate ovules are characterized by the presence of a well-developed nucellus.
- The nucellus is the central part of the ovule that surrounds and protects the female gametophyte.
- In crassinucellate ovules, the nucellus is thick and consists of several layers of cells.
- It provides nourishment and support to the developing embryo sac.
- The nucellus also plays a role in nutrient storage and the production of certain hormones.
- Crassinucellate ovules are found in various plant families, including gymnosperms and angiosperms.
Therefore, the correct answer is B: Well developed nucellus.

Ovule of an angiosperm is technically equivalent to a megasporangium.
Explanation:
- The ovule is a reproductive structure found in angiosperms, which are flowering plants.
- It contains the female reproductive cells called megaspores.
- The megaspores are produced within the ovule by a structure called the megasporangium.
- The megasporangium is the site of megaspore formation and is responsible for producing the female gametophyte.
- The female gametophyte, also known as the embryo sac, is formed from one of the megaspores.
- It is within the embryo sac that fertilization occurs, leading to the development of the embryo and ultimately the formation of seeds.
- Therefore, the ovule of an angiosperm is technically equivalent to a megasporangium as it houses and protects the megaspores and is involved in the process of female gametophyte development.

Explanation:
Integumentary Cells:
- Integumentary cells refer to the cells that make up the integument, which is the protective covering of the ovule.
- These cells play a crucial role in the development and maturation of the ovule.
Micropylar Region:
- The micropylar region is a specialized area at the opening of the ovule through which the pollen tube enters during fertilization.
- It is located at the opposite end of the funicle.
Ovule in Castor:
- The ovule in castor, like in other plants, is the structure that eventually develops into a seed after fertilization.
- It consists of various parts, including the integuments, micropyle, nucellus, and embryo sac.
Proliferation of Integumentary Cells:
- In the castor plant, the proliferation of integumentary cells specifically occurs at the micropylar region of the ovule.
- This proliferation is important for the proper development and protection of the ovule.
- The increased number of integumentary cells helps in the formation of the outer seed coat.
Answer:
The correct answer is C: Caruncle.
- The caruncle is a specialized structure found in some seeds, including those of castor.
- It is located at the micropylar end of the seed and is involved in nutrient absorption and seed coat adhesion.
- The proliferation of integumentary cells at the micropylar region contributes to the development and formation of the caruncle in castor seeds.

Caruncle is formed by:
- The integument is responsible for the formation of the caruncle.
- The caruncle is a specialized structure found in the seeds of some plants.
- It is usually located at the micropyle end of the seed and appears as a small, fleshy outgrowth.
- The caruncle serves various functions such as aiding in seed dispersal and attracting seed dispersers.
- It can provide a food source for animals, encouraging them to consume the seed and disperse it elsewhere.
- The caruncle is formed as a result of the development and differentiation of the integument tissues.
- The integument is the outer layer of the ovule, which eventually becomes the seed coat after fertilization.
- During seed development, the integument undergoes modifications to form the caruncle.
- These modifications may include changes in cell shape, size, and accumulation of specific substances.
- The caruncle can vary in shape, size, and color, depending on the plant species.
- Examples of plants that have seeds with caruncles include castor beans and tamarind.

Obturators which help in fertilization are outgrowth of:
The correct answer is C. Placenta or funiculus
Here is a detailed explanation:
1. Definition of Obsturators:
Obturators are structures that aid in the process of fertilization in plants. They serve as barriers or guides to facilitate the successful union of male and female reproductive cells.
2. Origin of Obsturators:
Obturators are outgrowths of specific plant structures. In the case of fertilization, they are derived from the placenta or funiculus.
3. Placenta:
The placenta is a specialized tissue found in the ovary of a flower. It plays a crucial role in the development of seeds. It is responsible for nourishing the developing ovule and facilitating the transfer of nutrients and water to the growing embryo.
4. Funiculus:
The funiculus is a stalk-like structure that connects the ovule to the ovary wall. It serves as a conduit for nutrient transport between the placenta and the developing seed.
5. Function of Obsturators:
The obsturators derived from the placenta or funiculus help in the process of fertilization by performing the following functions:
- Guiding the pollen tube: The obsturators provide a pathway for the pollen tube to travel towards the ovule, ensuring the direct delivery of male gametes to the female reproductive cells.
- Preventing the entry of unwanted pollen: The obsturators act as barriers, preventing the entry of pollen from other plant species or incompatible mates. This helps to ensure successful fertilization between genetically compatible individuals.
- Promoting efficient pollen tube growth: The obsturators may secrete substances that promote the growth and development of the pollen tube, ensuring its successful penetration into the ovule.
In conclusion, obsturators that aid in fertilization are outgrowths of the placenta or funiculus. They play a crucial role in guiding the pollen tube, preventing the entry of unwanted pollen, and promoting efficient fertilization in plants.

Explanation:
The diploid structure in the ovule of Capsella just before fertilization is the Nucellus/ Sec.nucleus. Here is a detailed explanation:
- The ovule is the female reproductive structure in plants that develops into a seed after fertilization.
- The diploid structure in the ovule is called the nucellus or secondary nucleus.
- The nucellus is a haploid tissue that surrounds the embryo sac, which contains the female gametes.
- Just before fertilization, the nucellus undergoes changes to support the development of the embryo.
- It provides nourishment to the developing embryo and acts as a protective layer.
- The nucellus also plays a role in the formation of the seed coat.
- After fertilization, the nucellus develops into the endosperm, which provides nutrients to the developing embryo.
- The endosperm is triploid, meaning it contains three sets of chromosomes.
- Therefore, the diploid structure in the ovule of Capsella just before fertilization is the nucellus or secondary nucleus.
Answer: B (Nucellus/ Sec.nucleus)

Filiform apparatus are found in:


There are four options given and we need to determine where filiform apparatus are found.
Let's break down each option and explain where filiform apparatus are found:
A. Antipodal cell:
- Filiform apparatus is not found in antipodal cells.
- Antipodal cells are located at the opposite end of the embryo sac and are involved in supporting the growth and development of the embryo.
B. Egg cell:
- Filiform apparatus is not found in egg cells.
- Egg cells are the female gametes and are involved in fertilization with the sperm to form the zygote.
C. Secondary nucleus:
- Filiform apparatus is not found in the secondary nucleus.
- The secondary nucleus is involved in the fusion with the male gamete to form the endosperm nucleus.
D. Synergids:
- Filiform apparatus is found in synergids.
- Synergids are two cells located near the egg cell in the embryo sac.
- The filiform apparatus is a specialized structure found at the micropylar end of the synergids.
- It helps in guiding the pollen tube towards the egg cell during fertilization.
Therefore, the correct answer is D. Synergids.

Explanation:
In Capsella, the type of gametes present are non-motile.
Here is a detailed explanation:
1. Gametes are the reproductive cells that fuse during sexual reproduction to form a zygote.
2. In Capsella, which is a genus of flowering plants, the gametes are non-motile.
3. Non-motile gametes do not have the ability to move on their own.
4. Unlike flagellated or motile gametes, which have a flagellum (tail) that allows them to swim towards each other for fertilization, non-motile gametes rely on external agents such as wind, water, or pollinators for their transfer and fertilization.
5. In the case of Capsella, the non-motile gametes are transferred through pollination, where pollen grains containing the male gametes are carried from the anthers to the stigma of the flower.
6. Once the pollen grains reach the stigma, they germinate and the non-motile male gametes are released to fertilize the non-motile female gametes present in the ovule.
7. This fertilization leads to the formation of a zygote, which develops into an embryo and eventually gives rise to a new plant.
In conclusion, the type of gametes present in Capsella are non-motile, which rely on external agents for fertilization.

Perisperm is:
- Persistent nucellus in seed: The correct answer is A. Perisperm refers to the persistent nucellus in a seed. Nucellus is the central part of the ovule and it usually degenerates after fertilization. However, in some seeds, the nucellus persists and becomes the perisperm, which serves as a source of nutrients for the developing embryo.
- Ovule wall: Perisperm is not the ovule wall. The ovule wall consists of integuments that enclose the nucellus and the embryo sac.
- Ovule coat: Perisperm is not the ovule coat. The ovule coat refers to the integuments that protect the ovule and later develop into the seed coat.
- Fossil of haustoria: Perisperm is not a fossil of haustoria. Haustoria are specialized structures in some parasitic plants that enable them to absorb nutrients from their host plants. Fossils of haustoria would refer to the preserved remains of these structures, which is not related to perisperm.
In summary, perisperm is the persistent nucellus in a seed, which serves as a source of nutrients for the developing embryo.

Free nuclear division in an angiosperm takes place during endosperm formation.
Explanation:
- Free nuclear division, also known as nuclear endoreduplication, is a process in which the nucleus of a cell undergoes multiple rounds of DNA replication without cytokinesis (cell division).
- This process commonly occurs during endosperm formation in angiosperms, which is the development of the nutritive tissue in the seed.
- The endosperm is formed through the fusion of a sperm cell with two polar nuclei in the embryo sac. This fertilization event triggers the formation of endosperm.
- Following fertilization, the endosperm nucleus undergoes free nuclear division, resulting in the formation of multiple nuclei within a single cell.
- The endosperm serves as a nutrient reserve to support the development of the embryo and seedling.
- Free nuclear division in endosperm formation allows for the rapid increase in nuclear DNA content, leading to the enlargement of the endosperm tissue.
- This process is essential for the successful development and growth of the angiosperm seed.
- It is important to note that free nuclear division can also occur in other tissues or organs of angiosperms, such as the developing fruit or pollen grains. However, in the context of the given options, endosperm formation is the most appropriate answer.