Reproduction In Plants Complete & Bonus Question answers+ Pdf | Class 7 Science

Reproduction In Plants Complete & Bonus Question answers is important for the students of 7th standard. Notes are provided here in such a way that students can understand the Chapter in an interesting way. This Reproduction In Plants Complete & Bonus Question answers could provide extra benefits in excelling a students curriculum . Students should practice their solutions regularly to prepare effectively for their examination.

I. Tick the correct option to complete each sentence .

1. The male reproductive part of the flower is the…

a) pistil

b) stigma

c) stamen  ✔

d) ovary

2. An orange flower is not unisexual because it has…

a) both stamens and pistil  ✔

b) either a pistil or stamen

c) petals and pistil

d) petals and sepals

3. When pollen grains from a flower reach the stigma of a flower of another plant of the same kind, it is called….

a) self- pollination

b) cross- pollination  ✔

c) fertilisation

d) insect pollination

4. An insect pollinated flower will most probably have…

a) no leaves

b) brightly coloured fruits

c) colourful petals  ✔

d) no petals

5. The union of a male gamete with a female gamete is known as…

a) pollination

b) cross- pollination

c) fertilisation  ✔

d) self- pollination

6. Algae reproduce by…

a) fragmentation  ✔

b) budding

c) layering

d) grafting

II. Fill in the blanks

1. The egg cell develops inside the ovule.

2. The radicle develops into the root system.

3. Seeds of sycamore are dispersed by wind.

4. Turmeric and ginger are examples of rhizomes.

5. The tip of the style of a flower is called the stigma.

6. The male gametes are inside the  pollen tube.

III. Answer the following questions in one sentence.

1. How is a rose plant propagated?

Ans: A rose plant is propagated through cuttings from its stem.

2. Which is the female reproductive part of a flower?

Ans: The pistil or carpel is the female reproductive part of a flower.

3. What is a zygote?

Ans: A zygote is a fertilised egg cell produced when a female gamete and a male gamete combine.

4. On which part of the pistil do the pollen grains settle during the pollination?

Ans: During pollination, pollen grains settle to the stigma part of the pistil.

5. Which part of a flower develops into a fruit?

Ans: A flower’s ovary develops into a fruit.

6. Give an example of a unisexual flower.

Ans: Papaya is an example of a unisexual flower.

IV. Answer the following questions in two sentences.

1. What is vegetative reproduction? Explain with an example.

Ans: Vegetative reproduction is a form of asexual reproduction in plants, in which multicellular structures seperate from the parent plant and develop into new individuals with the same genetic makeup. Example: The tuber of the potato ;when  a piece of potato consisting a bud is planted into the soil, it can grow into a new potato plant.

2. Explain how does Spirogyra multiply.

Ans: Under favourable conditions ,Spirogyra which is a common freshwater algae breaks down into fragments on its own and then each fragment grows into a new organism.

3. What is tissue culture?

Ans: Tissue culture is a form of asexual propagation. It involves production of plants from very small plant parts under special conditions.

4. What is sexual reproduction?

Ans: Sexual reproduction of plants refers to the fusion of male and female gametes, resulting in the formation of a zygote, which then develops into a new individual.

5. How do wind and bees help in the formation of seeds?

Ans: Wind helps in the formation of seeds by carrying pollen from the male part of the plant to the female part, enabling fertilization. Bees help by transferring pollen from flower to flower, increasing the chances of pollination and fertilization.

6. Define fertilization.

Ans: Fertilization is the process in which the male gamete fuses with the egg to form the zygote. The zygote then forms the embryo and the ovule develops into a seed.

7. Describe the embryo of a seed.

Ans: The embryo of a seed consists of a radicle and plumule. Upon germination, the radicle will develop into the root system, while the plumule will develop into the shoot system.

8. What is seed dispersal? Give an example.

Ans: The spreading away of seeds from the mother plant is known as seed dispersal. Eg: Dispersal by wind- Seeds of milkweed are extremely light and are blown away by wind to faraway places.

V. Answer the following questions in about 4 to 5 sentences.

1. List the artificial methods of vegetative propagation .Explain any one of them.

Ans: Vegetative propagation of plants is a kind of asexual reproduction through which new plants develop from vegetative parts like roots, stems or leaves.The most common artificial methods of  vegetative propagation include cutting , layering, grafting and tissue culture.

Cutting – Plants like roses, cacti, and other types can be multiplied by taking stem cuttings. A cutting of one of these plants grows shoots and roots when its cut end is immersed in soil, creating a new plant.

2. Explain with a neat labelled diagram the structure of a typical flower.

Ans: A typical flower has four parts-sepals, petals, stamens and a carpel.

Sepals: Sepals are the outermost layer of a flower, usually green in color, and are arranged in a whorl around the base of the flower. They protect the developing bud and eventually form the outermost part of the flower.

Petals: Petals are located inside the sepals and are usually brightly colored and fragrant. They serve to attract pollinators, such as bees and butterflies, to the flower.

Stamen: The stamen is the male reproductive organ of the flower and is made up of two parts: the filament and the anther. The filament is a long, thin stalk that supports the anther, which is the part that produces pollen.

Carpels: Carpels, also known as pistils, are the female reproductive organs of the flower. They consist of three parts: the stigma, the style, and the ovary. The stigma is a sticky surface at the top of the pistil that receives pollen. The style is a long, slender stalk that connects the stigma to the ovary, which contains the ovules that will eventually develop into seeds when fertilized by pollen.

3. Differentiate between unisexual and bisexual flowers.

Ans: Unisexual and bisexual flowers are two types of flowers that differ in their reproductive structures and the number of sex organs they possess.

Unisexual Flowers :

Unisexual flowers are those flowers that have only one reproductive organ (either stamen or carpel) and are not capable of self-fertilization. They are either male or female flowers, and each type of flower can be found on the same plant (monoecious) or on different plants (dioecious). The male flowers contain only stamens, which produce pollen, while female flowers have only carpels, which produce ovules. Examples of unisexual flowers include those found on papaya, pumpkin, and kiwi plants.

Bisexual Flowers :

Bisexual flowers, also known as hermaphrodite or perfect flowers, have both male and female reproductive organs within the same flower. They are capable of self-fertilization, meaning the flower can produce both male and female gametes and fertilize itself. Bisexual flowers are typically found in angiosperms and can be further classified as complete or incomplete. Complete flowers have all four whorls (sepals, petals, stamens, and carpels), while incomplete flowers lack one or more of these whorls. Examples of bisexual flowers include those found on roses, lilies, and daisies.

In summary, unisexual flowers have only one reproductive organ and are either male or female, while bisexual flowers have both male and female reproductive organs and are capable of self-fertilization.

4. Differentiate between cross pollination and self pollination.

Ans: Cross-pollination and self-pollination are two different processes of pollination that occur in flowering plants.

Cross-pollination is the transfer of pollen grains from the anther of a flower of one plant to the stigma of a flower of another plant of the same species. In other words, the pollen from one plant fertilizes the ovules of another plant. This process can happen through various agents, including wind, water, insects, and animals. Cross-pollination results in genetic variation in offspring, which is essential for the survival of the species.

On the other hand, self-pollination is the transfer of pollen from the anther to the stigma of the same flower or to another flower of the same plant. In other words, the pollen from one plant fertilizes the ovules of the same plant. Self-pollination results in less genetic variation in offspring compared to cross-pollination.

5. Explain the process of fertilization in plants.

Ans: Fertilization in plants is the process by which the male and female reproductive cells unite to form a zygote, which eventually develops into an embryo. The process of fertilization in plants can be divided into the following steps:

Pollination: Pollination is the transfer of pollen grains from the anther of a male flower to the stigma of a female flower. Pollination can occur through various agents, including wind, water, insects, and animals.

Germination of pollen: Once the pollen grain reaches the stigma, it germinates and produces a pollen tube that grows through the style and reaches the ovule.

Fusion of gametes: The pollen tube releases two male gametes into the ovule. One male gamete fuses with the egg cell to form a zygote, and the other male gamete fuses with the polar nuclei to form the endosperm. This process is called double fertilization.

Development of the zygote: The zygote develops into an embryo, and the endosperm develops into a nutritive tissue that nourishes the embryo.

Seed development: The ovary wall enlarges and becomes the fruit that contains the seeds. The seeds eventually mature and are dispersed through various means, such as wind, water, and animals.

Overall, the process of fertilization in plants is essential for sexual reproduction and the production of seeds. It is a complex process that involves the interaction between male and female reproductive cells, and it results in the formation of a zygote that develops into an embryo.

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