WBBSE Solutions For Class 10 Life Science And Environment Chapter 2 Sexual Reproduction In Flowering Plants

Chapter 2 Sexual Reproduction In Flowering Plants Summary

• A flower is the main reproductive part of sexual reproduction in flowering plants. A typical flower has four whorls of which the calyx is protective in nature and the corolla helps in pollination by attracting pollinating agents.
• Therefore, these are called as accessory whorls, as they don’t take part in reproduction directly. Androecium contains stamen which produces pollen. The gynoecium consists of carpels. The female gamete is produced within the ovary of the carpel.
• The transfer of pollen from another of the stamen to the stigma of the carpel is called pollination. When the pollen of one plant is transferred to the stigma of a flower located in the same plant, then it is called as self-pollination.
• Self-pollination within the same flower is called autogamy and between two flowers of the same plant is called geitonogamy. When pollens are deposited on the stigma located in different plants of same or different species, then it is called as cross-pollination.

Wbbse Class 10 Life Science Solutions

• Cross-pollination is also known as xenogamy or allogamy. Both self and cross-pollination have advantages and disadvantages. Cross-pollination needs vectors like air (rice) water (Hydrilla), insect (mango), bird (silk cotton), etc.
• Offspring produced through cross-pollination are with greater genetic variation than the offspring of self-pollination. The male gamete from pollen and the female gamete in ovule fuses together to form a diploid zygote.
• This fusion of gametes is called fertilization. The zygote forms the embryo. The ovule along with the embryo becomes a seed and the ovary along with the seed is transformed into fruit.
• On getting favorable conditions seed germinates to produce a new baby plant at the end of dormancy.

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Chapter 2 Sexual Reproduction In Flowering Plants Long Answer Type Questions

Question 1. Describe the structure of a typical flower.

Answer:

Structure of a typical flower:

A typical flower has all four floral parts (calyx, corolla, androecium, and gynoecium) arranged in concentric rings on the flat, thick disc-like thalamus (example-Hibiscus). The different floral parts of a typical flower are described below.

1. Calyx:

The calyx is the first or outermost whorl of the flower, which is green, cup-shaped, and composed of mostly five leafy segments, called sepals.

In certain plants, at the base of the calyx, there are some narrow leaf-like projections, which constitute the epicalyx (example-Hibiscus).

2. Corolla:

It is the second whorl, located towards the inner side of the calyx. Petals are white in colour with sweet smell or of any bright colour other than green. It is composed of leafy units called petals.

3. Androecium:

It is the third whorl, present at the inner side of the corolla. It is composed of three to many units, known as stamens. Each stamen has two parts, a fine, elongated, slender, cylindrical filament and a small, sac-like anther on it. Within the anther, the pollens are produced.

4. Gynoecium:

It is the fourth and central floral part of a typical flower. It may be composed of one or more units called carpels or pistils. Each carpel has three components-ovary, style and stigma. The ovary is the swollen base of a carpel.

The filamentous portion emerging from it is called style, which ends in a swollen, knob-like structure called the stigma.

Wbbse Class 10 Life Science Solutions

Question 2. Why is a flower called a modified shoot? Distinguish between the accessory and essential whorls.

Answer:

Flower is a modified shoot:

A flower is called a modified shoot due to the following features-

1. Like leaf buds, floral buds also grow from the axil or tip of a stem.
2. The floral parts are arranged on the thalamus like the arrangement of leaves on the stem.
3. Like the stem, the thalamus also has nodes and internodes.
4. Sepals and petals have similar venations like leaves.

Distinguishing features between the accessory and essential whorls

Question 3. Mention the important features of self-pollination.

Answer:

Important features of self-pollination:

1. Self pollination occurs in monoecious plant.
2. The stamens and carpels of self-pollinating flowers mature at same time.
3. This pollination occurs within the same flower (autogamy) or between separate flowers of the same plant (geitonogamy).
4. It generally occurs in bisexual flowers.
5. Loss of pollens in self-pollination is almost negligible.
6. Plants produced from self-pollination do not have newer characters.
7. Offspring produced through self-pollination show little or no genetic variations with their parents. On the contrary, qualitative degradation is evident in successive generations.
8. Pollinating agents are usually not required in this pollination.

Question 4. Mention important features of cross-pollination.

Answer:

Important features of cross-pollination:

1. Cross-pollination occurs mostly in unisexual flowers.
2. The male and female floral parts of cross-pollinating bisexual flowers mature at different times.
3. Due to structural barriers, self-pollination is hindered in some bisexual flowers, and as a result cross-pollination occurs.
4. Pollinating agents are essential for cross-pollination.
5. The hybrids produced through cross-pollination, show different higher genetic variations as compared to their parents.

Question 5. Mention the advantages and disadvantages of self and cross-pollination.

Answer:

Advantages and disadvantages of self and cross-pollination:

Question 6. Explain with examples the methods of cross-pollination by various pollinating agents. Part question, Which agents perform the function of pollination in the following plants? Paddy, Hydrilla, Shimul, Mango

Answer:

Cross-pollination by different pollinating agents:

Question 7. Mention differences between self-pollination and cross-pollination.

Answer:

Differences between self-pollination and cross-pollination

Question 8. Describe the structure of an ovule with a diagram of its longitudinal section.

Similar question, Draw a labelled diagram of the longitudinal section of an ovule of flowering plant. Structure of ovule Longitudinal section of an ovule reveals the structural detail of the same.

Answer:

1. Funiculus:

The small stalk-like structure, that attaches the ovule on the placenta, is called a funiculus.

2. Chalaza:

The base of the ovule from which the integuments develop is called a chalaza.

3. Hilum:

The point of attachment of the funiculus with chalaza is known as hilum.

4. Integument:

Single or double-layered coating of the ovule is called an integument.

5. Nucellus:

The thin nutritive tissue layer below the integuments, that surrounds the embryo sac, is called nucellus.

6. Micropyle:

The minute opening, just opposite to chalaza of the ovule, which is not covered by the integuments, is called the micropyle.

7. Embryo sac:

The thin membrane-bound, large sac-like cell, inside the nucellus is known as the embryo sac. It carries eight haploid (n) nuclei in the beginning of its formation. Out of these eight nuclei, three, present near the micropyle, constitute the egg apparatus.

One of these form the ovum or egg cell and two others form synergids. Three other nuclei arranged in a cluster near the chalaza are known as antipodal cells. The remaining two nuclei unite near the center of the embryo sac to form a diploid definitive nucleus (2n).

What Are Angiosperms Class 10

Question 9. Describe the method of fertilization and development of a new plant in angiosperms with a diagram. Similar question, Draw the labelled diagram of the fertilization process in angiospermic plant. Part question, State what happens in the following three phases of sexual reproduction of flowering plants

1. Production of gamete or reproductive cell.
2. Fertilization and
3. Formation of an embryo and new plant.

Answer:

Fertilization in angiosperms and development of new plants:

The method of fertilization in angiosperms and the development of a new plant includes a number of steps, which are described below.

1. Pollen formation:

Numerous haploid pollen grains (n) are formed inside anthers by meiotic division of diploid (2n) pollen mother cells. The haploid nucleus of pollen divides mitotically to produce two haploid nucleus, viz.-tube nucleus, and generative nucleus.”

 

2. Production of egg cell:

The ovary of a flower contains one to many ovules. Each ovule has a haploid (n) nucleus.

This nucleus undergoes three consecutive mitotic divisions to form eight nuclei, four of which stay at each pole of the ovule. Three of these nuclei stay at the chalazal pole in a cluster.

These are called antipodal cells (n) and one polar nucleus (n) moves to the center of the ovule. At the opposite pole, three nuclei remain near the micropylar pole and one polar nucleus moves towards the center.

Of these three, one nucleus becomes more conspicuous, which forms the egg cell or ovum (n), and the remaining two stay near the pole as the synergids (n). At the centre, the two polar nuclei unite to form a diploid definitive nucleus (2n).

What Are Angiosperms Class 10

3. Pollination:

In this phase, pollens from the same or separate flower of the same or another plant of the same species are transferred to the stigma. After successful pollination, the pollen grain germinates to produce a pollen tube which grows through the style towards the ovary.

Meanwhile, two haploid male gametes ar formed within the pollen from the generative nucleus.

4. Fertilisation and zygote formation:

As soon pollen tube enters into the style, two male gametes move toward the tip of it. The pollen tube then enters into the ovule by any of the three paths, viz.-through micropyle (porogamy), through chalaza (chalazogamy) or through integuments (monogamy).

After piercing the membrane of the embryo sac, the tip of the pollen tube dissolves to release the two male gametes inside it. Here, one male gamete fertilises the egg cell (n) to form a diploid (2n) zygote.

The other male gamete fertilizes the definitive diploid nucleus (2n) to form a triploid endosperm nucleus (3n). In the case of sexual reproduction in angiosperms plants, fertilization occurs two times. Therefore, this type of phenomenon is known as double fertilization.

5. Embryo formation:

The zygote undergoes continuous mitosis division to form a multicellular embryo.

6. Formation of fruit and seed:

The ovule with embryo transforms into seed and the ovary matures as fruit.

7. Germination of seed and formation of new plant:

In the presence of favourable temperature, light, oxygen, water, hormones, and enzymes, the seed germinates. The radicle gives rise to the root system and the plumule grows to form the shoot.

Chapter 2 Sexual Reproduction In Flowering Plants Short Answer Type Questions

Question 1. What is a flower?

Answer:

Flower:

A flower is a highly condensed, specially modified shoot of plants, with limited growth. It is customised to protect the reproductive whorls (androecium and gynoecium) within it and thus, help in sexual reproduction.

Question 2. Mention the important features of a flower.

Answer:

The important features of a flower are as follows-

1. Flower is a specially modified shoot of a plant.
2. Flower grows from apical or axillary buds.
3. A flower has four whorls-calyx, corolla, androecium, and gynoecium.

Question 3. What is meant by a typical flower?

Answer:

Typical flower:

A typical flower is that flower, which has all the four floral parts, i.e. calyx, corolla, androecium, and gynoecium, arranged in a proper concentric circles on a thalamus.

Example-Hibiscus, lily rose, etc.

Question 4. What are the functions performed by a typical flower?

Answer:

Different functions of a typical flower are-

1. Sexual reproduction in flowering plants is performed by a flower.
2. After fertilization, the flower is transformed into a fruit which contains seeds for the formation of new generation.

Question 5. What is a pedicel? Mention its function.

Answer:

1. Pedicel: The slender, cylindrical, stalk-like structure, that holds the thalamus of a flower on a branch of the stem, is called pedicel.
2. Function of Pedicel: Pedicel connects the flower with the stem of a plant.

Question 6. What is meant by a pedicellate and sessile flower?

Answer:

1. Pedicellate flower:

The flower, which is held on a branch with the help of a pedicel, is called a pedicellate flower.

Example-Hibiscus rose, etc.

2. Sessile flower: The flower, which does not possess a pedicel and directly attaches with the stem, is called a sessile or non-pedicellate flower.

Example-Tube rose.

 

 

Question 7. What is the thalamus? Mention its function.

Answer:

Thalamus:

The convex or flat or concave, compact and thick disc-like structure, present on the top of the pedicel, is called the thalamus. It has nodes and internodes.

Function:

Upon the thalamus, the floral parts remain arranged in whorls or in a spiral fashion. Thus the thalamus holds these floral parts.

Question 8. What is meant by a complete flower?

Answer:

Complete flower:

A flower carrying all four floral parts or whorls, i.e. calyx, corolla, androecium, and gynoecium, is called a complete flower.

Example-Clitoria, Hibiscus, mustard flower, etc.

Question 9. What is meant by an incomplete flower?

Answer:

Incomplete flower:

A flower, lacking any one or more of the four floral parts or whorls, i.e. calyx, corolla, androecium, and gynoecium, is known as an Incomplete flower.

Example- Flowers pumpkins, gourds, etc.

Question 10. What is meant by unisexual flowers?

Answer:

Unisexual flowers:

A flower, which has any one of the two reproductive floral parts, i.e. androecium and gynoecium, is known as an unisexual flower. The flower having androecium only is called a male flower or staminate flower.

On the other hand, the flower that carries the gynoecium only is known as a female or pistillate flower.

Example-Flowers of pumpkin.

Question 11. What is meant by a bisexual flower?

Answer:

Bisexual flower:

A flower, having both the reproductive whorls, i.e., androecium and gynoecium, is called a bisexual flower.

Example-Flowers of Hibiscus, Datura, etc.

Question 12. What is meant by neuter or sterile flower?

Answer:

Neuter or sterile flower:

A flower, lacking both androecium and gynoecium, is called neuter or sterile flower.

Example-Ray florets of sunflower, some flowers of arum, etc.

Question 13. Differentiate between complete and incomplete flower.

Answer:

Differentiate between complete and incomplete flower are

Question 14. What is meant by a regular flower?

Answer:

Regular flower:

The flowers, which have every single unit of a whorl like petals, sepals, etc. with identical size and shape, are called regular flowers.

Example-Flower of Hibiscus, datura, etc.

 

Question 15. What is meant by an irregular flower?

Answer:

Irregular flower:

Α flower in which one or more members of single or several floral whorls differ in size and shape from other members, is called irregular flower. Irregular flower (Pea flower)

Example-Flowers of sweet peas, Clitoria, etc.

Question 16. What is meant by an asymmetric flower? Give an example.

Answer:

Asymmetric flower:

A flower, which is indivisible into two equal halves at any of the planes through the axis, is called an asymmetric flower.

Example:

The orchid flower is the example of an asymmetric flower.

Question 17. What is meant by the monoecious plant?

Answer:

Monoecious plant:

The plant, which carries separate male and female flowers on the same plant body, is called a monoecious plant.

Example-Pumpkin, gourd, etc.

Question 18. What is meant by the dioecious plant?

Answer:

Dioecious plant:

The plant, which carries male and female flowers on separate plant bodies, is called a dioecious plant.

Example-Papaya, palm, etc.

Question 19. What is meant by calyx?

Answer:

Calyx:

The green-colored outermost whorl of a flower, that protects all other floral parts within a bud, is called calyx. The leafy units of a calyx are called sepals.

Question 20. What are sepals?

Answer:

Sepals:

The green leafy units, which unite to compose a calyx, are known as sepals. Generally, three to five sepals form a calyx. Sepals of a flower are either free from each other or united together.

The sepals protect the other parts of a flower while those are inside the flower bud.

Question 21. Mention two functions of the calyx.

Answer:

Two functions of the calyx are-

1. While in the bud, the calyx protects all other floral parts from bright light, heat, rain, and insect attacks.
2. Calyx has mesophyll tissue which helps in photosynthesis.

Question 22. What is epicalyx?

Answer:

Epicalyx:

In some flowers (example-Hibiscus), an additional whorl of smaller leafy projections occurs at the junction of the calyx and thalamus. This whorl of floral part is called epicalyx.

In some floral buds, the epicalyces provide additional protection to the other floral parts along with the calyces.

Question 23. What is meant by corolla?

Answer:

Corolla:

The most conspicuous and second whorl of a flower, which is white or of any colour other than green is known as a corolla. Corolla is meant to attract insects for pollination and protecting the reproductive parts from external injury. The leafy units of the corolla are known as petals.

Question 24. Mention the functions of the corolla.

Answer:

The functions of the corolla are-

1. It protects the androecium and gynoecium from external injury while in the bud and even after blooming.
2. It attracts insects for helping in pollination by its sweet smell and bright colour.

Question 25. Why are calyx and corolla treated as ‘accessory floral parts’ of a flower?

Answer:

The calyx and corolla do not take part in the reproduction process directly. Instead, they protect androecium and gynoecium within the bud and the petals attract insects to help in pollination.

Therefore, calyx and corolla are treated as ‘accessory floral parts’.

Question 26. What is meant by a naked flower?

Answer:

Naked flower:

The flower which does not have any of the two accessory floral parts, i.e., calyx and corolla, so as to leave the essential reproductive parts (androecium and gynoecium) exposed, is called a naked flower.

Example-Poinsettia pulcherrima.

Question 27. Distinguish between calyx and corolla.

Answer:

Distinguishing features between calyx and corolla are-

Question 28. What is meant by androecium? Mention its function.

Answer:

Androecium:

The essential third whorl of a flower, located towards the inner side of the corolla and composed of three to many stamens, is known as androecium.

Function:

Androecium is meant for the production of pollens, the male reproductive units of a flower.

Question 29. What is meant by gynoecium? Mention its function.

Answer:

Gynoecium:

The essential fourth whorl of a flower, composed of one or more carpels, located at the centre of the floral axis, is known as gynoecium.

Function:

Gynoecium produces the egg cell and acts as the centre for production of fruit and seed.

Question 30. What is meant by pollination?

Answer:

Pollination:

The transfer of pollens from the anther of a flower to the stigma of the same flower or another flower of the same plant or a separate plant of the same species is known as pollination.

Pollination successfully initiate the further development within the pollen and the ovary.

Question 31. Mention two differences between self-pollinating and cross pollinating plants.

Answer:

Two main differences between self-pollinating and cross pollinating plants are-

Question 32. What is meant by autogamy?

Answer:

Autogamy:

In certain bisexual flowers, both stamens and carpels mature simultaneously, resulting in self pollination. Eventually, male gamete of a flower fertilises egg of the same flower. This event is known as autogamy.

Example-Autogamy occurs in flowers of sweet pea, Clitoria, Sesbania, etc.

Question 33. What is meant by geitonogamy?

Answer:

Geitonogamy:

In some monoecious plants, the pollen of a flower is transferred to the stigma of another flower of the same plant. The fertilization that occurs as a result of this pollination is known as geitonogamy.

Example-Geitonogamy occurs in the flowers of pumpkin.

Question 34. Differentiate Between autogamy and geitonogamy.

Answer: Differences Between autogamy and geitonogamy are-

Wbbse Class X Life Science

Question 35. Mention the characteristic features of wind-pollinated or anemophilous flowers.

Answer:

The characteristic features of anemophilous flowers are-

1. Flowers are small, dull in colour, and inconspicuous.
2. Sepals and petals are small to expose the reproductive parts.
3. These flowers do not secrete nectar.
4. The stamens have longer filaments to expose the anthers outside of the accessory floral whorls. Stamens are versatile, suspended, and well oscillated by wind currents for better dispersal of pollen.
5. Pollens are very fine, light in weight, and numerous.
6. Stigma is large, hairy or feathery for successful catching of pollens from air (example-Paddy flower).

Question 36. Why do the anemophilous flowers have small sepals and petals?

Answer:

In anemophily, wind acts as the pollinating agent. Therefore, the anthers need maximum exposure to wind. That is why the sepals and petals of anemophilous flowers become very small and wide apart to expose the stamens to the blowing wind.

Question 37. Mention the characteristic features of water-pollinated or hydrophilous flowers.

Answer:

The characteristic features of hydrophilous flowers are as follows-

1. Hydrophilous flowers are small and inconspicuous.
2. Sepals and petals are small. Calyx, corolla, and other floral parts are mostly water-resistant in nature.
3. Nectar and fragrance are absent.
4. Submerged flowers have heavier pollens but floating ones have lighter, floating pollens.
5. The outer surface of pollens as well as the stigma are coated with a waxy water-resistant material (example-Hydrilla flower).

Question 38. Mention the characteristic features of insect-pollinated or entomophilous flowers.

Answer:

Some characteristic features of entomophilous flowers are

1. Petals are brightly coloured and widely open.
2. The nectar gland is present at inner side of the flower.
3. Nocturnal flowers are white but have a sweet smell. Nectar and fragrance are the rewards for the pollinators.
4. The outer coating of pollens is rough or sticky to adhere to the body. parts of insects.
5. The stigma is knob-shaped and with the rough, very sticky surface to adhere the pollens (example-Mango flower).

Question 39. Why do entomophilous flowers have brightly coloured petals, sweet smell and nectar?

Answer:

Flowers blooming during the daytime are brightly colored, while nocturnal flowers have a sweet smell. All these three above-mentioned features are meant for attracting insects for pollination.

Therefore, entomophilous flowers have brightly coloured petals, sweet smell, and nectar.

Question 40. Why does the surface of stigma of the entomophilous flower has sticky fluid on it?

Answer:

The stigma of the entomophilous flower has sticky fluid on its surface to capture the pollens from the body parts of insects. This fluid also initiates pollen tube formation.

Question 41. How does the position of the nectar glands help in entomophilous pollination?

Answer:

Nectar glands are located at the innermost position of a flower. Insects have to enter deep into the flower to collect nectar. During this activity, the body parts of the insects come in contact of anthers (to collect pollens) and stigma (to deposit pollens), thus helping in pollination.

Question 42. Write about the characteristic features of bird-pollinated or ornithophilous flowers.

Answer:

Some of the characteristic features of ornithophilous flowers are-

1. Flowers are large with big and widely open petals.
2. The petals are vividly brightly colored, especially red.
3. These flowers are highly rich in dilute nectar.
4. Some of these flowers have tasty anthers, which are often eaten by birds (example-Silk cotton flowers).

Wbbse Class X Life Science

Question 43. Differentiate between wind and insect-pollinated flower.

Answer:

Differences between wind and insect-pollinated flowers are-

Question 44. Cross-pollination is more beneficial than self-pollination Explain.

Answer:

Cross-pollination is more beneficial than self-pollination because

1. In cross-pollination union/combination of genetic material from two different plants takes place, which gives rise to higher level of variation. As a result, the offspring possess advanced characteristics. They have higher immunity, stress tolerance, and productivity. These features/phenomena can not be seen in case of self-pollination.
2. The offspring born due to cross-pollination help in evolution of that particular species as genetic variation takes place.

Question 45. What is micro gametogenesis?

Answer:

Micro gametogenesis:

The process by which haploid nucleus of pollen divides after the sucessful pollination and forms 3 nuclei, is called microgametogenesis. In pollen sac, microspore or pollen (n) is developed from pollen mother cell (2n).

It is the first cell of the male gametophyte. Division and development of the nucleus of pollen grain takes place through micro gametogenesis and gives rise to two male gametes and one tube nucleus.

Question 46. What is megagametogenesis?

Answer:

Megagametogenesis:

The process by which haploid (n) megaspore in the ovary of a flowering plant divides through mitosis and forms a multinuclear embryo sac or female gametophyte, is called megagameto- genesis.

During this process, two synergids (n), one ovule (n), two polar nuclei (n) [together they form a definitive nucleus (2n)] and three antipodal cells (n) are developed.

Question 47. What is meant by porogamy?

Answer:

Porogamy:

Sometimes the pollen tube enters in to the embryo sac through the micropyle of the ovule. This is known as porogamy.

Question 48. What is meant by chalazogamy?

Answer:

Chalazogamy:

Sometimes the pollen tube enters into the embryo sac through the chalazal end of the ovule. This is known as chalazogamy.

Question 49. What is meant by mesogamy?

Answer:

Mesogamy:

Sometimes the pollen tube enters into the embryo sac through the integuments of the ovule. This is known as mesogamy.

Question 50. What is ovule?

Answer:

Ovule:

The small, spherical or oval structure within the ovary is covered by an integument and holds the egg cell is called the ovule. The ovule transforms into seed after fertilization.

Question 51. What is egg apparatus?

Answer:

Egg apparatus:

In the embryo sac of flowering plants, out of 8 haploid (n) nuclei, 3 nuclei are situated towards micropyle. Out of these 3, one is ovule and rest of two are synergids. These three cells are together called egg apparatus.

Wbbse Class X Life Science

Question 52. What is meant by polar nuclei?

Answer:

Polar nuclei:

Within the embryo sac of angiosperms, a haploid nucleus undergoes three consecutive mitotic divisions to form eight haploid nuclei, distributed equally at two poles.

Out of these, two nuclei from two opposite poles approach the middle of the embryo sac. These two nuclei are called polar nuclei which ultimately fuse to form diploid definitive nuclei (2n).

Question 53. How is the definitive nucleus formed in the embryo sac?

Answer:

The developing embryo sac of angiosperms has eight haploids (n) nuclei, four distributed at each pole. Out of these, two polar nuclei from two opposite poles approach towards the middle.

At the final stage of development, they fuse to form a diploid definitive nucleus (2n) inside the embryo sac.

Question 54. How is the endosperm nucleus produced in angiosperms?

Answer:

During fertilization in angiosperms, a haploid male gamete (n) fertilizes the diploid) definitive nucleus (2n) within the embryo sac. By this process, a triploid endosperm nucleus (3n) is formed in the embryo sac of angiosperms.

Question 55. Explain what will happen to a bisexual flower if its carpels are removed.

Answer:

The Carpel of a flower is made up of stigma, style, and ovary. Removal of the carpel means removal of stigma, style, and as well as ovary. If we remove the carpel, then the process of pollination which is rendered by stigma will be hampered.

Consequently, the style and ovary can’t complete the process of fertilization. Thus the formation of fruit and seeds will not occur.

Double Fertilization Class 10

Question 56. What is double fertilization?

Answer:

Double fertilization:

In angiosperms, one of the two haploids (n) male gametes fertilizes the egg cell (n) and another male gamete (n) fertilizes the diploid (2n) definitive nucleus, inside the ovule.

Since, this process involves two successive fertilisations, so it is known as double fertilisation. The first fertilisation, results into a diploid zygote (2n) and the second one forms a triploid endosperm nucleus (3n).

Question 57. Write down the chromosome set number of the following cells (1 set = n)-

1. Antipodal cell,
2. Definitive nucleus,
3. Tube nucleus,
4. Endosperm,
5. Male gamete,
6. Spore mother cell,
7. Egg mother cell.

Answer:

The chromosome set number of the cells mentioned in the question are-

1. Antipodal cell- one (n),
2. Definitive nucleus-two (2n),
3. Tube nucleus-one (n),
4. Endosperm-three (3n),
5. Male gamete-one (n),
6. Spore mother cell- two (2n),
7. Egg mother cell-two (2n).

Wbbse Class X Life Science

Question 58. If the endosperm of a plant species contains 36 chromosomes, then what is the number of chromosomes present in male gamete and female gemete?

Answer:

In the angiosperms endosperm, there are 3 sets of chromosomes, i.e. 3n = 36. As the games contain 1 set of chromosomes, the number of chromosomes present in male gamete and female gamete or egg should be n = 12.

Question 59. Write the significance of fertilization.

Answer:

The significances of fertilization are-

1. In sexual reproduction, a zygote can only be formed by the occurrence of the union of gametes or double fertilization is capable of storing food for fertilization.
2. Endosperm developed through the future growing embryo.

Question 60. Mention the fate of different floral parts after fertilization.

Answer:

Fate of different floral parts after fertilization is enlisted below in the tabular form.

Question 61. What is the embryonic axis?

Answer:

Embryonic axis:

The tiny axial. embryonic structure, from which the radicle (embryonic root) and plumule (embryonic shoot) germinate from the seed, is known as the embryonic axis.

The embryonic axis below the cotyledon-attachment site is called the hypocotyl, which is the progenitor of the root.

Question 62. Name the floral parts which get degenerated after fertilization.

Answer:

The floral parts which get degenerated after fertilization are calyx, corolla, the filament of stamen, style of the carpel, synergies, and antipodal cells inside the ovule.

Chapter 2 Sexual Reproduction In Flowering Plants Very Short Answer Type Questions Multiple Choice Questions And Answers [Mcq]

Question 1. Flower is a modified—

1. Root
2. Leaf
3. Inflorescence
4. Shoot

Answer: 4. Shoot

Question 2. The shoot with limited growth, which is modified for reproduction and meant for the production of fruits and seeds, is—

1. Root
2. Flower
3. Leaf
4. Branch

Answer: 2. Flower

Question 3. The floral parts remain arranged on a flat thick base, which is known as—

1. Sepal
2. Thalamus
3. Petiole
4. Ovary

Answer: 2. Thalamus

Question 4. The number of floral parts in a complete flower is—

1. Three
2. Four
3. Five
4. Six

Answer: 2. Four

Class 10 Life Science Wbbse

Question 5. The flower, which has sepals, petals,’ androecium, and gynoecium arranged on the thalamus, is called—

1. Regular flower
2. Complete flower
3. Inflorescence
4. Incomplete flower

Answer: 2. Complete flower

Question 6. The accessory floral parts of a flower are—

1. Calyx and gynoecium
2. Androecium and gynoecium
3. Corolla and calyx
4. Corolla and androecium

Answer: 3. Corolla and Calyx

Question 7. A flower having both androecium and gynoecium is called—

1. Unisexual flower
2. Bisexual flower
3. Actinomorphic flower
4. Irregular flower

Answer: 2. Bisexual flower

Question 8. Which of the following is not a bisexual flower?

1. Datum
2. Tube rose
3. Bok (Sesbania) flower
4. Bottle gourd flower

Answer: 4. Bottle gourd flower

Question 9. The flower, in which either androecium or gynoecium is absent, is called—

1. Bisexual flower
2. Regular flower
3. Irregular flower
4. Unisexual flower

Answer: 4. Unisexual flower

Question 10. Androecium and gynoecium directly take part in reproduction, therefore, these two floral parts are called—

1. Helping whorls
2. Accessory whorls
3. Essential whorls
4. Unnecessary whorls

Answer: 3. Essential whorls

Question 11. The outermost floral part is—

1. Calyx
2. Thalamus
3. Corolla
4. Androecium

Answer: 1. Calyx

Question 12. The number of sepals in the Hibiscus flower is—

1. 3
2. 4
3. 5
4. 6

Answer: 3. 5

Question 13. The number of sepals in a Datura flower is—

1. Three
2. Four
3. Five
4. Six

Answer: 3. Five

Question 14. Epicalyx is present in—

1. Bok (Sesbania) flower
2. Hibiscus
3. Sweet pen flower
4. Datum

Answer: 2. Hibiscus

Question 15. An example of an irregular flower is—

1. Pea flower
2. Pumpkin
3. Datura
4. Hibiscus

Answer: 1. Pea flower

Question 16. The complete, regular, polypetalous flower is—

1. Datura
2. Bok (Sesbania)
3. Hibiscus
4. Pumpkin

Answer: 3. Hibiscus

Question 17. A regular, unisexual flower is—

1. Hibiscus
2. Datura
3. Pumpkin
4. Pea flower

Answer: 3. Pumpkin

Question 18. Which of the following flowers is an example of a regular, complete, gamopetalous flower?

1. Sweet pea flower
2. Datura flower
3. Aparajita (Clitoria) flower
4. Bok (Sesbania) flower

Answer: 2. Datura flower

Question 19. Calyx and corolla unite to form a combined structure in some flowers. This structure is called— ,

1. Thalamus
2. Perianth
3. Naked flower
4. Bract

Answer: 2. Perianth

Class 10 Life Science Wbbse

Question 20. A flower without calyx and corolla is called—

1. Unisexual flower
2. Bisexual flower
3. Naked flower
4. True flower

Answer: 3. Naked flower

Question 21. Each unit of perianth is called—

1. Tepal
2. Petal
3. Sepal
4. Calyx

Answer: 1. Tepal

Question 22. The perianth is present in the flowers of—

1. Tube rose
2. Datura
3. Sunflower
4. Hibiscus

Answer: 1. Tube rose

Question 23. Plants of the same species, carrying male flowers on one plant and female flowers on another, is called—

1. Zygomorphic
2. Monoecious
3. Bisexual
4. Dioecious

Answer: 4. Dioecious

Question 24. A plant bearing male, female, and bisexual flower altogether, Is called—

1. Monoecious
2. Dioecious
3. Polygamous
4. Monogamous

Answer: 1. Monoecious

Class 10 Life Science Wbbse

Question 25. The discoverer of sex in plants is—

1. Camerarius
2. Nawaschin
3. Linnaeus
4. Sanger

Answer: 1. Camerarius

Question 26. Which of the following is not a component of androecium?

1. Anther
2. Filament
3. Ovule
4. Pollen

Answer: 3. Ovule

Question 27. In which part of the flower, pollens are produced?

1. Stigma
2. Filament
3. Ovary
4. Anther

Answer: 4. Anther

Question 28. The waxy coating is seen on the surface of pollens in—

1. Anemophilous flowers
2. Hydrophilous flowers
3. Entomophilous flowers
4. Ornithophilous flowers

Answer: 2. Hydrophilous flowers

Question 29. Which of the following is not a component of gynoecium?

1. Stigma
2. Style
3. Pollen
4. Ovule

Answer: 3. Pollen

Question 30. The number of stigma in the Hibiscus flower is—

1. 2
2. 3
3. 5
4. Numerous

Answer: 2. 5

Question 31. Embryo sac in flowering plants is formed by—

1. Embryo
2. Megaspore
3. Zygote
4. Nucellus

Answer: 2. Megaspore

Class 10 Life Science Wbbse

Question 32. The embryo sac is present in—

1. Anther
2. Pollen tube
3. Ovule
4. Stigma

Answer: 3. Ovule

Question 33. The small pore present above the funiculus is called—

1. Stoma
2. Micropyle
3. Node
4. Epicoutyl

Answer: 2. Micropyle

Question 34. The polar nucleus is located in—

1. Thalamus
2. Egg cell
3. Pollen tube
4. Embryo sac

Answer: 4. Embryo sac

Question 35. Pollination means—

1. Growth of pollen tube inside the ovule
2. Visiting of flowers by insects
3. Germination of pollen grain
4. Transfer of pollens from anther to the stigma

Answer: 4. Transfer of pollens from anther to stigma

Question 36. In which of the following flowers does self-pollination occur?

1. Gourd
2. Pumpkin
3. Papaya
4. Evening primrose

Answer: 4. Evening primrose

Question 37. Pollination between two unisexual or bisexual flowers of the same plant is called—

1. Homogamy
2. Cleistogamy
3. Geitonogamy
4. Xenogamy

Answer: 3. Geitonogamy

Question 38. Pollination by transfer of pollens from anthers of a flower of a plant to the stigma of another flower borne on a separate plant of either same species or different species is treated as—

1. Cross-pollination
2. Homogamy
3. Cleistogamy
4. Geitonogamy

Answer: 1. Cross-pollination

Question 39. In which type of pollination, there is the possibility of variations in the next generation?

1. Cross-pollination
2. Self-pollination
3. Autogamy
4. Both 1 and 2

Answer: 1. Cross-pollination

Question 40. In which of the following plant’s water is not required for pollination?

1. Hydrilla
2. Maize
3. Selaginella
4. Vallisneria

Answer: 2. Maize

Question 41. Which type of pollination needs a pollinating agent?

1. Cross-pollination
2. Self-pollination
3. Autogamy
4. Both 1 and 2

Answer: 1. Cross-pollination

Question 42. Cross-pollination between flowers of two different plants of the same species is known as—

1. Homogamy
2. Cleistogamy
3. Geitonogamy
4. Xenogamy

Answer: 4. Xenogamy

Question 43. An example of an anemophilous flower is—

1. Paddy
2. Hydrilla
3. Mango
4. Shimul

Answer: 1. Paddy

Class 10 Life Science Wbbse

Question 44. An example of the hydrophilous flower is—

1. Sugarcane
2. Hydrilla
3. Mango
4. Shimul

Answer: 2. Hydrilla

Question 45. An example of the entomophilous flower is

1. Maize
2. Hydrilla
3. Mango
4. Shimul

Answer: 2. Hydrilla

Question 46. Pollination by the help of birds is known as

1. Entomophily
2. Omithophily
3. Psychophily
4. Anthropophily

Answer: 2. Omithophily

Question 47. Pollination by insects is known as—

1. Omithophily
2. Malacophily
3. Anthropophily
4. Entomophily

Answer: 4. Entomophily

Question 48. An example of an ornithophilous flower is—

1. Hydrilla
2. Hibiscus
3. Shimul
4. Maize

Answer: 3. Shimul

Question 49. In anemophily, the pollinating agent is—

1. Water
2. Insects
3. Air
4. Birds

Answer: 3. Air

Question 50. Select which of the following is the feature of cross-pollination.

1. Occurs within the same flower of the same plant
2. Agents are not required
3. Lesser chance of new characters being transmitted
4. More wastage of pollen grains

Answer: 4. More wastage of pollen grains

Question 51. In which cellular state, pollen is liberated from the anther?

1. Unicellular
2. Two to three cellular state
3. Four to five cellular state
4. Six cellular state

Answer: 2. Two to three cellular state

Question 52. Entrance of pollen tube in embryo sac through integument of the ovule is called—

1. Mesogamy
2. Porogamy
3. Chalazogamy
4. Cleistogamy

Answer: 1. Mesogamy

Question 53. Entrance of pollen tube within the ovule through micropyle is known as—

1. Monogamy
2. Porogamy
3. Chalazogamy
4. Cleistogamy

Answer: 2. Porogamy

Question 54. Sexual reproduction in angiosperms was discovered by—

1. Nawaschin
2. Maheshwari
3. Camerarius
4. Strasburger

Answer: 4. Strasburger

Question 55. Fertilisation in angiospermic plants occurs inside—

1. Stigma
2. Ovum
3. Anther
4. Embryo sac

Answer: 4. Embryo sac

Question 56. Which one of the following statement is correct regarding sexual reproduction?

1. Haploid gamete formation is essential in sexual reproduction
2. Sexual reproduction depends only on mitosis
3. In sexual reproduction, offspring could be produced from a single parental organism ‘
4. The offspring produced in sexual v reproduction are genetically identical with a parental organism

Answer: 1. Haploid gamete formation is essential in sexual reproduction

Question 57. In which of the following plants’ double fertilization is seen?

1. Angiosperms
2. Gymnosperms
3. Bryophytes
4. Pteridophytes

Answer: 1. Angiosperms

Question 58. If the chromosome number of the root cells of an angiospermic plant is 32, the chromosome number of the gametes will be—

1. 0
2. 16
3. 24
4. 32

Answer: 2. 16

Question 59. The number of chromosomes in zygote is

1. N
2. 2N
3. 3N
4. 4N

Answer: 2. 2N

Question 60. Which of the following parts supplies food to the growing embryo?

1. Cotyledons
2. Water
3. Soil
4. Air

Answer: 1. Cotyledons

Question 61. Fertilized ovum matures to form—

1. Embryo
2. Seed
3. Ovule
4. Fruit

Answer: 1. Embryo

Question 62. Seeds are produced from—

1. Stigma
2. Ovule
3. Ovum
4. Ovary

Answer: 2. Ovule

Question 63. On attaining maturity, the integument of the ovule transforms into—

1. Seed coat
2. Ovum
3. Endosperm
4. Fruit

Answer: 1. Seed coat

Wbbse Class 10 Life Science Solutions

Chapter 2 Sexual Reproduction In Flowering Plants Answer In A Single Word Or Sentence

Question 1. What are the other names of sexual reproduction?
Answer: Amphimixis and syngenesis

Question 2. What is the name of the process of gamete formation?
Answer: Gametogenesis

Question 3. What does a zygote form by mitotic cell division?
Answer: An embryo

Question 4. How do you denote the arrangement of flowers on a plant?
Answer: Inflorescence

Question 5. What is main function of a flower?
Answer:

Main function of a flower

The main function of a flower is to carry out the sexual reproduction of the plant.

Question 6. Which portion of a shoot grows as a flower?
Answer: Floral bud

Question 7. How do you denote the axis of a flowering plant, which carries a cluster of flowers?
Answer: Peduncle

Question 8. Absence of which floral part reduces the attractiveness of a flower for the insects?
Answer: Petals

Question 9. How do you designate the small stal-like structure that holds a flower on a branch?
Answer: Pedicel

Question 10. Name the floral parts, which remain arranged on the thalamus.
Answer:

The floral parts, which remain arranged on the thalamus are-

1. Calyx,
2. Corolla,
3. Androecium and
4. Gynoecium.

Question 11. Name the units of a calyx.
Answer: Sepals

Question 12. What do you call each unit of the corolla of a flower?
Answer: Petal

Question 13. Name the long tubular part of gynoecium, that is connected to the ovary and holds the stigma.
Answer: Style

Question 14. From where are the male gametes of a flower produced?
Answer: Pollen grains

Question 15. What is the first cell of the male gametophyte?
Answer: Pollen grain

Question 16. What are the different cells present in pollen grain during pollination?
Answer: One generative nucleus and one tube nucleus

Question 17. Give example of a flower, which has a tube-like calyx.
Answer: Datura sp.

Question 18. How do you denote each unit of the gynoecium?
Answer: Carpel

Question 19. Give examples of two monoecious plants.
Answer: Gourd and pumpkin plants

Question 20. Give examples of two dioecious plants.
Answer: Papaya and palm trees

Question 21. Name the parts of a carpel.
Answer:

Parts of a carpel

Stigma, style, and ovary

Question 22. Which two parts of a flower mature to form fruit and seed?
Answer: The ovary and ovule of a flower respectively mature to form fruit and seed.

Question 23. How many thalami are present in a flower?
Answer: A flower has only one thalamus (A singular form of thalami).

Question 24. Name the event of a union of male and female gametes.
Answer: Fertilisation

Question 25. Which type of cell division, does a pollen mother cell undergo to form pollens?
Answer: Meiotic cell division

Question 26. Which famous scientist first observed the event of pollination in date palm tree?
Answer: Greek botanist Theophrastus

Question 27. Which scientist coined the term ‘double fertilization’?
Answer: Russian botanist S G Nawaschin (1898)

Question 28. Which are the reproductive parts of a flower?
Answer: Stamens and carpels

Question 29. State the location of the ovule in a carpel.
Answer: The ovule is located inside the ovary of a carpel.

Question 30. Mention the chromosome number of the definitive nucleus.
Answer: Diploid (2n) number of chromosomes

Question 31. What is the chromosome number of the endosperm nucleus?
Answer: Triploid (3n) number of chromosomes

Question 32. Write down the common name and scientific name of an anemophilous flower.
Answer: Common name of an anemophilous flower is paddy and its scientific name is Oryza sation.

Question 33. What is zoophily?
Answer:

Zoophily

Zoophily is a type of cross-pollination which is facilitated by different animals (example-bat, snails, insects, birds, etc.) is called zoophily.

Question 34. Write down the scientific name of a hydrophilous flower.
Answer: Hydrilla verticillata

Question 35. Write down the common name and scientific name of an entomophilous flower.
Answer: Common name of an entomophilous flower is the mango flower and its scientific name is Mangifera indica.

Question 36. Write down the common name and scientific name of an ornithophilous flower.
Answer: Common name of an ornithophilous flower is silk cotton and its scientific name is Bombax ceiba.

Question 37. What does the definitive nucleus create after fertilization?
Answer: After fertilization, the definitive nucleus (2n) produces an endosperm nucleus (3n), which later divides to create the endosperm of the developing seed.

Question 38. What does a pollen nucleus produce after its division?
Answer: The pollen nucleus divides to produce one generative nucleus and one tube nucleus.

Question 39. How many stamens are there in the flower of Hydrilla?
Answer: 30-40 stamens

Question 40. Name two flowers, which bloom at night and which do not have bright colours?
Answer: Flowers of Polianthes tuberosa and Cestrum nocturnum bloom at night and do not have bright colours

Question 41. Name the unit of androecium that is composed of a filament and an anther.
Answer: Stamen

Question 42. Name the first cell of male gametophyte.
Answer: Pollen

Question 43. Name the thicker outer coating of the pollen grain.
Answer: Exine

Question 44. Name the delicate inner coating of a pollen grain.
Answer: Intine

Question 45. What will happen to a bisexual flower if all of its stamens are removed?
Answer: If all stamens of a bisexual flower are removed, the flower will survive as a unisexual female flower.

Question 46. What does the funiculus of the ovule transform into after fertilization?
Answer: Funiculus is transformed into a seed-stalk after fertilization of ovule.

Question 47. What will happen to the Hibiscus flower it all is petals are cut off just after its blooming?
Answer: If the petals of a Hibiscus are cut off just after its blooming entomophily entomophily will be obstructed.

Question 48. Why is the stigma of paddy flowers long and feathery?
Answer: The stigma of paddy flowers is long and feathery to catch the air-borne pollens.

Question 49. Why do the pollens of entomophilous flowers have a spiny and sticky outer surface?
Answer: Pollens of entomophilous flowers have a spiny and sticky outer surface to adhere to the body parts of visiting insects.

 

Chapter 2 Sexual Reproduction In Flowering Plants Fill In The Blanks

Question 1. Flower is the _________ organ of a plant.
Answer: Reproductive

Question 2. Sepals and petals are the _________ parts of a flower.
Answer: Accessory

Question 3. Flowers grow from apical or _________ buds.
Answer: Axillary

Question 4. In angiosperms, certain portions of the _________ is modified into flower.
Answer: Shoot

Question 5. The leaf-like segments of a calyx are called _________.
Answer: Sepals

Question 6. The thin cylindrical portion of a stamen is known as _________.
Answer: Filament

Question 7. The capsular portion at the top of a filament is known as_________.
Answer: Anther

Question 8. Pollen divides to form _________ gametes.
Answer: Male

Question 9. The third floral part of a complete flower is called _________.
Answer: Androecium

Question 10. The calyx of the Datura flower appears like a _________.
Answer: Bell

Question 11. The tubular portion that remains in between stigma and _________ is known as style.
Answer: Ovary

Question 12. Pollens settle on _________of aflower during pollination.
Answer: Stigma

Question 13. The androecium of the Datura flower is composed of _________ stamens.
Answer: Five

Question 14 Sweet pea flower has _________ stamens in its androecium.
Answer: Ten

Question 15. The slightly swollen head-like portion of the style of a gynoecium is called _________.
Answer: Stigma

Question 16. Pollination within the same flower is called _________.
Answer: Homogamy

Question 17. Pollination between two flowers of the same plant is known as _________.
Answer: Geitonogamy

Question 18. In _________ pollination, pollinating agents are required for the transfer of pollens.
Answer: Cross

Question 19. In _________, pollination occurs with the help of wind.
Answer: Anemophily

Question 20. In hydrophily, _________ acts as the pollinating agent.
Answer: Water

Question 21. Insects act as pollinating agents in the case of _________ flowers.
Answer: Entomophilous

Question 22. Palash is an ornithophilous flower, where _________ helps in pollination.
Answer: Birds

Question 23. When pollen tube enters into the ovule through _________, it is called porogamy.
Answer: Micropyle

Question 24. In the case of chalazogamy, the pollen tube enters into the ovule through _________ end.
Answer: Chalazal

Question 25. Radicle, plumule, and cotyledons develop from _________ of a seed.
Answer: Embryo

Question 26. The diploid _________ divides consecutively to form an embryo.
Answer: Zygote

Question 27. The embryo sac of an angiosperm ovary carries _________ haploid nuclei.
Answer: Eight

Question 28. A fertilized ovule matures to form a _________.
Answer: Seed

Question 29. The embryo of a plant remains protected inside a _________.
Answer: Seed

Question 30. _________ of a plant grows from the radicle.
Answer: Root

Question 31. _________ of a plant grows from the plumule.
Answer: Shoot

Question 32. The Union of a diploid (2n) definitive nucleus and a haploid (n) _________ gamete forms a triploid endosperm nucleus.
Answer: Male

Question 33. Xenogamy is a type of _________ pollination.
Answer: Cross

Question 34. Sessile flowers do not possess _________.
Answer: Pedicel

Question 35. A flower remains attached to the branch by _________.
Answer: Pedicel

Question 36. An ovary of a flower may contain one or more _________.
Answer: Ovules

Question 37. The petals of the Datura flower remain attached to each other along their length, hence, it is a _________ flower.
Answer: Gamopetalous

Question 38. Hibiscus carries all four floral parts, therefore, it is called a _________flower.
Answer: Complete

Question 39. The flower of the sweet pea plant has five asymmetrical petals, hence, it is called a /an _________ flower.
Answer: Irregular

Question 40. Pollination of paddy, maize, and sugarcane occurs by _________.
Answer: Win

Question 41. The sexual reproductión that occurs among two genotypically different organisms belonging to the same species is called _________.
Answer: Intraspecific hybridization

Wbbse Class 10 Life Science Solutions

Chapter 2 Sexual Reproduction In Flowering Plants State True Or False

Question 1. The accessory floral parts of a flower are sepals and petals.
Answer: True

Question 2. Each part of a corolla is called a petal.
Answer: True

Question 3. Pollens are haploid in nature.
Answer: True

Question 4. The future plant remains protected within a seed.
Answer: True

Question 5. The seed coat and fruit coat of maize are inseparable.
Answer: True

Question 6. An ovary may carry one to many ovules.
Answer: True

Question 7. The pollinating agent is not required for cross-pollination.
Answer: False

Question 8. Pollinating agents are essential for self-pollination.
Answer: False

Question 9. Paddy is a hydrophilous plant.
Answer: False

Question 10. Hydrilla is a anemophilous plant.
Answer: False

Question 11. The mango flower shows entomophily.
Answer: True

Question 12. Silk cotton plant shows ornithophily.
Answer: True

Question 13. Anthers contain pollens.
Answer: True

Question 14. Blastula develops from morula.
Answer: True

Question 15. Zygote is haploid in nature.
Answer: False

Question 16. Ovum is only produced as a result of mitosis.
Answer: False

Question 17. Self pollination or cross pollination can be exercised in flowers of pea plant according to the need.
Answer: True

Question 18. The carpel of flowering plants collects pollen grains with the help of a hairy and sticky style.
Answer: False

 

Chapter 2 Sexual Reproduction In Flowering Plants Match The Columns

1.

Answer: 1. C, 2. G, 3. D, 4. B, 5. F, 6. A

2.

Answer: 1. F, 2. E, 3. A, 4. B, 5. D, 6. G

3.

Answer: 1. D, 2. E, 3. C, 4. B, 5. A, 6. F

4.

Answer: 1. C, 2. A, 3. B, 4. E, 5. D, 6. F

5.

Answer: 1. C, 2. A, 3. B, 4. E, 5. D, 6. F

6.

Answer: 1. A, 2. E, 3. F, 4. C, 5. G, 6. B

 

Chapter 2 Sexual Reproduction In Flowering Plants Find The Odd One Out

Question 1. Ovary, Anther, Stigma, Style
Answer: Anther

Question 2. Sepal, Petal, Filament, Ovary
Answer: Ovary

Question 3. Hibiscus flower, Pea flower, Cucumber flower, Clitoria flower
Answer: Cucumber flower

Question 4. Antipodal cells, Definitive nucleus, Synergids, Tube nucleus.
Answer: Tube nucleus

Question 5. Self-pollination, Cross-pollination, Geitono gamy, Autogamy
Answer: Cross-pollination

Question 6. Porogamy, chalazogamy, Mesogamy, Isogamy
Answer: Isogamy

Question 7. Pollen, Egg, Fertilisation, Grafting
Answer: Grafting

Question 8. Ovary, Style, Stigma, Filament
Answer: Filament

Question 9. Synergids, Antipodal cell, Secondary fusion nucleus, Bud
Answer: Bud

 

Chapter 2 Sexual Reproduction In Flowering Plants Fill In The Blanks By Looking At The First Pair

Question 1. Ovary: Ovule :: Anther: ___________
Answer: Pollen

Question 2. Mango flower: Entomophilous flower:: Wheat flower: ___________
Answer: Anemophilous flower

Question 3. Calyx: Sepal:: Corolla: ___________
Answer: Petal

Question 4. Gynoecium: Carpel :: Androecium: ___________
Answer: Slamen

Question 5. Female gamete: n:: Endosperm: ___________
Answer: 3n

Question 6. Rose flower: Pedicellate:: Tube rose: ___________
Answer: Sessile

Question 7. Ovary: Fruit:: Ovule: ___________
Answer: Seed

Question 8. Porogamy: Micropyle:: Mesogamy: ___________
Answer: Integument

Question 9. Mitosis: Radicle :: ___________ :Spore mother cell
Answer: Meiosis

 

Chapter 2 Sexual Reproduction In Flowering Plants Among The Four Concepts Given Three Of Them Belong To One Find That

Question 1. Tiny colorless flower, Light pollen-bearing flower, Wind pollinating flower, Non-fragrant nectarless flower.
Answer: Wind-pollinating flower

Question 2. Entomophilous flower, Anemophilous flower, Hydrophilous flower, Cross-pollinating flower.
Answer: Cross-pollinating flower

Question 3. Sticky stigma and pollen-carrying flower, Insect pollinating flower, Fragrant night-blooming flower, Colourful day-blooming flower.
Answer: Insect-pollinating flower

Question 4. Androecium, Gynoecium, Calyx, Floral whorls.
Answer: Flower whorl

Question 5. Pea flower, Datura flower, Hibiscus flower, Complete flower.
Answer: Complete flower

Question 6. Air, Insect, Water, Vector of Pollination.
Answer: Vector of pollination

Question 7. Large flower, Bright colour, Tubular corolla, Ornithophilous flower.
Answer: Ornithophilous flower