NCERT Solutions for Class 7th Science Chapter 8 Reproduction in Plants according to the Latest Syllabus Of JKBOSE and CBSE NCERT Books
(I) Multiple Choice Questions – Tick mark (✓) the correct choice.
- The common method of reproduction in bacteria is
- (a) budding
- (b) fragmentation
- (c) binary fission (✓)
- (d) all the above
- Budding is commonly seen in
- (a) Yeast (✓)
- (b) Grasses
- (c) Amoeba
- (d) Bryophyllum
- Reproduction or propagation by stem is common in
- (a) Rose
- (b) Potato (✓)
- (c) Sweet potato
- (d) Bryophyllum
- Unisexual flowers are found in
- (a) Mulberry
- (b) Mustard
- (c) Pea (✓)
- (d) Sunflower
- A seed consists of
- (a) Embryo
- (b) Seed coat and cotyledons
- (c) Embryo and seed coat (✓)
- (d) Seed coat and endosperm
- An embryo of a seed consists of
- (a) Plumule
- (b) Radicle, plumule and cotyledons (✓)
- (c) Plumule and radicle
- (d) Radicle and cotyledons
(II) Fill in the blanks:
(a) Budding is a kind of asexual reproduction.
(b) The amount of cytoplasm in the parent cell is larger than the amount in the bud.
(c) Yeast cells reproduce by budding.
(d) Binary fission produces cells of equal size.
(e) Budding produces cells of unequal size.
(f) Fungi, ferns and mosses reproduce by spores.
(g) Male sex cells in plants are called pollen grains.
(h) The two kinds of pollination are self-pollination and cross-pollination.
(III) State whether the statements given below are true or false:
(a) Asexual reproduction is more common than sexual reproduction. True
(b) Producing life is called respiration. False
(c) Bacteria and yeast reproduce by asexual reproduction. True
(d) Reproduction by spores is a method of asexual reproduction. True
(e) A potato tuber is really an underground stem. True
(f) A whole new plant can grow from the eye of a tuber. True
(g) Cutting and grafting are natural means of reproduction. False
(h) Most organisms have the capacity of regeneration in some or the other ways. True
(i) Stamens make egg cells. False
(j) A fertilized egg becomes a seed. True
(k) Flowers which possess stamens and pistils are called unisexual. False
(l) Insect-pollinated flowers are brightly coloured. True
(IV) Differentiate between the following:
- Asexual reproduction and sexual reproduction
- Asexual reproduction: Involves only one parent, no fusion of gametes, offspring are genetically identical to the parent. Example: binary fission in bacteria.
- Sexual reproduction: Involves two parents, fusion of gametes, offspring are genetically different from the parents. Example: flowering plants.
- Binary fission and budding
- Binary fission: The parent cell divides into two equal halves, each becoming a new individual. Example: Amoeba.
- Budding: A new individual grows out of the body of the parent organism and detaches when mature. Example: Yeast.
- Self-pollination and cross-pollination
- Self-pollination: Pollen from the anther of a flower is transferred to the stigma of the same flower or another flower on the same plant.
- Cross-pollination: Pollen from the anther of a flower is transferred to the stigma of a flower on a different plant of the same species.
(IV) Differentiate between the following:
- Insect-pollinated flowers and wind-pollinated flowers
- Insect-pollinated flowers: These flowers are usually brightly colored and have a pleasant scent to attract insects. They often have nectar.
- Wind-pollinated flowers: These flowers are not brightly colored and do not have a strong scent. They produce a large amount of lightweight pollen that is carried by the wind.
- Zygote and embryo
- Zygote: A zygote is the initial cell formed when two gamete cells are joined by means of sexual reproduction.
- Embryo: An embryo is the early stage of development of a multicellular organism. In plants, it develops from the zygote and eventually forms the seed.
(V) Find the odd one out, giving reasons:
- Gamete, budding, fragmentation, regeneration.
- Odd one out: Gamete. Reason: Gamete is involved in sexual reproduction, while the others are methods of asexual reproduction.
- Cutting, grafting, layering, binary fission.
- Odd one out: Binary fission. Reason: Binary fission is a method of asexual reproduction in unicellular organisms, while the others are vegetative propagation methods in plants.
- Ovary, stigma, style, pollen grain.
- Odd one out: Pollen grain. Reason: Pollen grain is the male gamete, while the others are parts of the female reproductive organ of a flower.
(VI) Name the following:
- Part of the flower where ovule is found.
- Answer: Ovary.
- Three agents of pollination.
- Answer: Wind, insects, water.
- The place where fertilization occurs in the flowering plant.
- Answer: Ovule.
(VII) Mention the functions of the following:
- Flower: The reproductive structure in flowering plants.
- Anther: Produces and releases pollen grains.
- Ovary: Contains ovules and develops into fruit after fertilization.
- Stigma: The part of the pistil where pollen germinates.
- Seed dispersal: The process by which seeds are spread away from the parent plant to reduce competition and increase the chances of survival.
(VIII) Answer the following questions:
- Why is reproduction necessary for living organisms?
- Reproduction is necessary for the continuation of species and the transmission of genetic material to the next generation. It ensures genetic diversity and the survival of species over time.
- How much of the parent’s nuclear material does each daughter cell get during reproduction by binary fission?
- Each daughter cell gets an equal amount of the parent’s nuclear material, resulting in two genetically identical cells.
- What kind of reproduction is binary fission?
- Binary fission is a type of asexual reproduction where a single organism divides into two identical daughter cells. It is common in prokaryotes like bacteria.
- How many parents take part in binary fission?
- Only one parent takes part in binary fission.
- Describe the various methods of asexual reproduction.
- Binary Fission: The parent cell divides into two equal parts, each becoming a new organism. Common in bacteria.
- Budding: A new organism develops from an outgrowth or bud on the parent. Common in yeast and hydra.
- Fragmentation: The parent organism breaks into fragments, each capable of growing into a new organism. Seen in starfish and some worms.
- Spore Formation: Organisms produce spores that can grow into new individuals. Common in fungi, ferns, and some algae.
- Vegetative Propagation: New plants grow from parts of the parent plant, such as roots, stems, or leaves. Methods include cutting, grafting, and layering.
- Describe the various methods of vegetative reproduction.
- Cutting: A part of the plant, typically a stem or leaf, is cut and planted to grow a new plant.
- Grafting: A section of a plant is attached to another plant, combining their strengths.
- Layering: A stem is bent and covered with soil to grow roots, after which it is cut to form a new plant.
- Tissue Culture: Cells or tissues from a plant are grown in a nutrient medium under sterile conditions to produce new plants.
- Mention two characteristic features of wind-pollinated flowers.
- They produce a large quantity of pollen.
- They have long stamens and pistils to expose pollen to the wind.
- Mention two features of insect-pollinated flowers.
- They have bright colors and produce nectar to attract insects.
- Their pollen is usually sticky or spiky to adhere to insects.
- Describe the various steps leading to the formation of seeds in plants.
- Pollination: Transfer of pollen from anther to stigma.
- Fertilization: Fusion of male and female gametes in the ovule.
- Zygote Formation: Formation of a zygote which develops into an embryo.
- Seed Development: The ovule matures into a seed containing the embryo.
- Seed Maturation: The seed develops protective structures and nutrients for the embryo.
- Describe the various ways by which seeds are dispersed.
- Wind Dispersal: Seeds are lightweight or have structures like wings or hairs to carry them by the wind.
- Water Dispersal: Seeds float and are carried by water currents.
- Animal Dispersal: Seeds are carried by animals, either externally by sticking to fur or internally by being eaten and excreted.
- Mechanical Dispersal: Seeds are ejected from the parent plant by force, as in the case of exploding seed pods.
(IX) Spell the missing word:
Fill in the missing letters to spell the terms that fit the definition:
- Stigma: Top part of the pistil.
- Egg: Female gamete.
- Embryo: Baby plant.
- Budding: Method of asexual reproduction.
(X) Spot the odd term:
In each of the following sets, one term does not belong to the set. Circle that term.
- Sexual reproduction, asexual reproduction, one parent
- Odd term: Sexual reproduction
- Sexual reproduction, asexual reproduction, two parents
- Odd term: Asexual reproduction
- Binary fission, bacteria, yeast
- Odd term: Yeast
- Binary fission, budding, yeast
- Odd term: Binary fission
- Stamen, anther, style
- Odd term: Style
