Telangana SCERT Class 7 Science Chapter 12 Solution – Reproduction In Plants. Here in this post we provides Class 7 Science Reproduction In Plants Telangana State Board Solution. Telangana State Board English Class VII Medium Students can download this Solution to Solve out Improve Your Learning Questions and Answers.
Telanagana State Board Class 7 Science Chapter 12 Reproduction In Plants Solution:
Question 1: Do all flowers have same parts? Classify the flowers according to the parts of flower present in them and give examples.
Ans. All flowers do not have same parts. Flower consists of mainly four parts. Sepal, Petal, Stamen and Pistil. Based on presence and absence of floral parts flower are two types. Complete flower and Incomplete flower.
Any flower that does not have one more of these parts is known as incomplete flower.
Sepals are leaf like usually green. WShile flowers developing, it protect and enclose the flower.
Petals are usually colorful structures. Its functions is to attract pollinators for the purpose of reproduction.
Stamens are the male reproductive structure of flowers.
Pistils are the female reproductive structures.
Examples of complete flowers are datura, hibiscus.
Examples of incomplete flowers are sweet corn, squash plants, most of grasses etc.
Question 2: Differentiate between
a.) Bisexual flowers, Unisexual flowers
Ans. Ans. A flower has both stames and pistil are called bisexual flower. Examples – Datura, hibiscus. Ipomea
A flower which has either stames or pistil is called unisexual flower. Examples – Cucumber, bottle gourd, bitter gourd etc.
A bisexual flower has both male and female reproductive organs.
A unisexual flower has only one, either male or female reproductive organ.
b.) Complete flower, incomplete flower
Ans. A flower that has four or more parts at least one each of sepals, petals, stamens and pistil is called a complete flower.
Examples – Datura, ipomoea, hibiscus.
A flower in which any of these four part is missing is called incomplete flower.
Examples – cucumber, bottle gourd, papaya.
c.) Male flower, female flower
Ans. Male flower have androecium.
Female flowers have Gynoecium.
Male parts – Stamen produces pollen grains,
female part – ovary / pistil produces ovum.
d.) Sexual reproduction, Asexual Reproduction
Ans. Production of baby plants or off springs from the zygote is called sexual reproduction.
Production of baby plants can grow even without formation of seeds that is without sexual reproduction. This is called asexual reproduction.
Sexual reproduction is mainly shown in mammals, birds, fish etc.
Asexual reproduction is used by many plants like potato, radish, onion etc.
e.) Self pollination, Cross pollination
Ans. Transfer of pollen grains take place within the flower it is known as self pollination.
Transfer of pollen grain from one flower to stigma of another flower of same species is called cross pollination.
Question 3. What happens when a pollen grain falls on a stigma?
Ans. When a pollen grain falls on a stigma, there are some substances present on the stigma which promote the germination of the pollen grains. A pollen grain on the stigma grows a tiny tube, all the way down the style to the ovary. The ovary develops into a fruit to protect the seed.
Question 4. What helps to bring pollen grains to the stigma?
Ans. Air, water, animals, insects, humans act as agents of pollination. They carry pollen grains from anther to the stigma. Insects like butterflies suck nectar from flowers. At that time pollen grains of that flower stick to the legs of the butterfly. When the butterfly goes to another flower for nectar, the pollen grain that have stuck to its legs fall on the flower. In that way it helps to bring pollen grains to the stigma.
Question 5. Explain the method of sexual reproduction in plants.
Ans. The transfer of pollen grains from anther to stigma known as pollination. In this process some substances are present on stigma, which promote germination of the pollen grains. A tube from pollen grain reaches to the ovary through the male part. This male part fuses with the female part in the ovule of the ovary.
Fusion of units of male and female parts known as zygote is called fertilisation.
After fertilisation seed develops from the ovule and the ovary develops into a fruit. This entire process of fertilization and formation of zygote is known as sexual reproduction.
For the formation of seed sexual reproduction is essential.
Question 6: Can plants produce new plants even without seeds? Explain the methods with examples.
Ans. Yes plants can produce new plants even without seeds. But not all plants grows from a seed. Like, potato, mosses, Bryophyllum they grow without seeds.
The methods are –
i) Vegetative reproduction: Production of new plants from vegetative parts of a plant like root, stem and leaf is known a vegetative reproduction.
Examples like – rose, hibiscus etc by cutting a small branch and planting them in the soil, then this plants can grown from its cutting.
ii) Budding: Making good jilbes a plant can help, it called yeast. Yeast grow with the help of small bulb which increases in size and breaks off from the parent plant to live independently. This process of reproduction is called budding.
iii) Spore formation: Not every plant grows from seed, some plants like ferns, mosses grow from spores. The spores are released and dispersed by the wind. If the spore lands in a suitable environment. it can grow into a tiny plant.
Question 7: Draw the diagram of any flower showing its parts.
Question 8: Do all plants reproduce in the same way? Explain with examples.
Ans. No, plants have two methods of reproduction.
Some plants reproduce sexually but maximum reproduce asexually.
So some plants grow from seeds and also some plants like mosses grow from spores. Some plants use asexual vegetation reproduction and grow new p[lants.
Now we can say that plants are reproduce by using these methods.
But all plants reproduce via pollination and also plants reproduce by the help of air, oxygen, water etc.
In sexual reproduction a baby plants of or off springs from the zygote.
In asexual reproduction a baby plants can grow even without formation of seeds that is without sexual reproduction.
Flowering plants are an example of sexual reproduction.
Bryophyllum is an example of asexual reproduction. Baby plants of these plants can grow on the edge of the leaves.
Question 9: . Karthik saw a cucumber plant in the kitchen garden. He identified two types of flowers-some flowers had a small swollen structure behind them while some did not. He removed all the flowers which did not have the swollen structure behind them thinking that they were of no use.
– Which flowers did he remove?
– What are the flowers which had a small fruit behind them?
Ans. He removed all the flowers which did not have the swollen structure. Mean he removed all the male flowers.
The flowers that had a small fruit behind them were female flowers. Only they can produce the cucumber fruit thats why Karthik was looking for in the cucumber plant.
Question 10: What are the agents of pollination?
Ans. Air, water, animals, insects, humans are the agents of pollination. They carry pollen grains from anther to the stigma.
Insects like butterflies are also helps in pollination.
Question 11: Differentiate between self pollination and cross pollination.
Ans. Pollination plays an important role in reproduction in plants. There are two types of pollination.
i) When pollen grains are transferred from anther to stigma of same flower or different flower of same plant. This is called self pollination.
When transfer of pollen grains from one flower to stigma of anther flower of same species is called cross pollination.
ii) Flowers do not depend on the other agencies for the self pollination.
Agents such as insects, water, wind are required for this cross pollination.
iii) Sunflowers, Orchids, Oats etc are the examples of self pollination.
Tulips, grapes, apples etc are the examples of cross pollination.
Question 12: Name the parts of the following plants from which they propagate vegetatively.
a) Potato b) Byrophyllum
Ans. (a) Potato: New plants grow from eyes in the tuber, which is a modified stem.
(b) Byrophyllum: New plants grow from buds at the end of leaves.
Question 13. What am I?
a) I am formed by the fusion of male and female parts.
b) I am a part of the plant that can travel a long distance and grow to a baby plant.
Ans. Seeds / Pollen grains.
Question 14. Fill in the blanks Answers:
(a) bisexual flower.
(b) cross pollination.
(c) buds on the leaf.
(d) Air, water, animals, insects, humans.