Reproduction in Plants Class 7 Worksheet Science Chapter 8

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Q.1. True/False
(i) A spore producing organism is bread mould.

True

Bread mould, particularly species like Rhizopus, is indeed a spore-producing organism. Here are some key points:

• It reproduces through spores, which are tiny reproductive units.
• These spores are released into the air and can travel long distances.
• When conditions are suitable, spores can germinate and grow into new mould.

(ii) Bryophyllum can reproduce by its stem.

False

Bryophyllum mainly reproduces through its leaves, not its stem. Here are some key points:

• It has buds along the edges of its leaves.
• When a leaf falls on moist soil, each bud can grow into a new plant.
• This method is known as vegetative propagation.

(iii) A bisexual flower has both the male and the female reproductive parts.

True

A bisexual flower has both male and female reproductive parts, specifically:

• Stamens - the male part that produces pollen.
• Pistils - the female part that contains ovules.

This structure allows the flower to engage in:

• Self-pollination - pollen from the same flower fertilises its ovules.
• Cross-pollination - pollen from one flower fertilises the ovules of another flower.

(iv) All organisms multiply or reproduce their own kind.

True

All living organisms have the ability to reproduce, which is essential for their survival. Here are some key points:

• Reproduction allows organisms to create offspring that are similar to themselves.
• This process can occur through various methods, including sexual and asexual reproduction.
• In asexual reproduction, a single organism can produce clones of itself.
• In sexual reproduction, offspring inherit traits from both parents.

(v)   In plants there are three modes of reproduction.

False

Plants reproduce mainly through two methods:

• Asexual reproduction: This occurs without seeds and includes methods like:
• Sexual reproduction: This involves the fusion of male and female gametes.
  • Fragmentation
  • Budding
  • Spore formation
  • Vegetative propagation

(vi) Leaf is the reproductive part of a plant.

False

The flower is the reproductive part of a plant, while leaves mainly assist in photosynthesis. 
Here are the key points:

• Flowers are responsible for reproduction.
• Leaves primarily help in making food for the plant.
• Reproductive functions are not performed by leaves.

Q.2. Fill in the blanks.
(i) Production of new individuals from the vegetative part of parent is called ____.

vegetative propagation

Vegetative propagation is a form of asexual reproduction in which new plants grow from the vegetative parts of the parent plant, such as roots, stems, or leaves.

(ii)  A flower may have either male or female reproductive parts. Such a flower is called ____.

unisexual
Unisexual flowers have either male (stamens) or female (pistils) reproductive structures, but not both.

(iii) The transfer of pollen grains from the anther to the stigma of the same or of another flower of the same kind is known as ____.

pollination
Pollination is a crucial process in plant reproduction, allowing for fertilization to occur when pollen reaches the stigma.

(iv) The fusion of male and female gametes is termed as ____.

fertilisation
Fertilisation occurs when a male gamete (sperm) fuses with a female gamete (egg), resulting in the formation of a zygote.

(v)  Seed dispersal takes place by means of ____, ____ and ____.

wind, water, animals
Seed dispersal mechanisms help plants spread their offspring over a wider area, reducing competition and promoting colonization of new habitats.

(vi) Anther contains pollen grains which produce ____.

male gametes
Pollen grains are the male gametes in flowering plants, essential for the process of fertilisation.

Q.3. What are the two modes of reproduction in plants?

In plants there are two modes of reproduction, asexual and sexual.

• Asexual reproduction: This method allows plants to produce new individuals without seeds. Common methods include:
  • Fragmentation
  • Budding
  • Spore formation
  • Vegetative propagation
• Sexual reproduction: This involves the fusion of male and female gametes, leading to the formation of seeds. Key points include:
  • Flowers are the reproductive parts of plants.
  • Pollination is the transfer of pollen from the anther to the stigma.
  • There are two types of pollination:
    • Self-pollination: Pollen transfers within the same flower.
    • Cross-pollination: Pollen transfers between different flowers.

Q.4. What is reproduction?

Reproduction is the process by which living organisms create new individuals.

It involves the production of offspring from their parents.

Reproduction can occur in two main ways:

• Asexual reproduction: New individuals are formed without seeds.
• Sexual reproduction: Offspring are produced from seeds.

Q.5. How do potatoes reproduce?

Potatoes reproduce asexually through vegetative reproduction. This process involves:

• Planting a piece of potato that has an eye.
• Watering it regularly for a few days.
• New stems will grow from the eyes, leading to the development of a potato plant.

Q.6. How does sexual reproduction take place in flowering plants?

The process of sexual reproduction in flowering plants involves several key components:

• The anther contains pollen grains, which produce male gametes.
• A pistil consists of three parts: stigma, style, and ovary.
• The ovary houses one or more ovules, where the female gamete (egg) is formed.
• During reproduction, a male gamete fuses with a female gamete to form a zygote.

This fusion is known as fertilisation, leading to the development of seeds and ultimately new plants. 

Q.7. How the male gamete in the pollen grain reaches the female gamete present in the ovule?

The male gamete in the pollen grain reaches the female gamete present in the ovule through a series of steps:

• Pollen grains have a tough protective coat that prevents them from drying out.
• They are lightweight and can be carried by wind, water, or insects.
• When insects visit flowers, they carry pollen on their bodies.
• Pollen lands on the stigma of the same flower or a different flower of the same species.
• This process is known as pollination, which can be either self-pollination or cross-pollination.
• Once on the stigma, the pollen grain germinates and grows a tiny tube down the style to the ovary.
• The pollen tube transports the male gamete to the female gamete located in the ovule.

Q.8. Describe the different methods of asexual reproduction. Give examples.

Different methods of asexual reproduction
Vegetative propagation - It is a type of asexual reproduction in which new plants are produced from roots, stems, leaves and buds. Example - Bryophyllum (sprout leaf plant) has buds in the margins of leaves. If a leaf of this plant falls on a moist soil, each bud can give rise to a new plant.
Fragmentation – It is a form of asexual reproduction in which an organism is split into fragments. Each of these fragments develop into matured, fully grown individuals that are clones of the original organism. Example – When water and nutrients are available algae grow and multiply rapidly by fragmentation.
Spore Formation – The spores are asexual reproductive bodies. In spore formation parent plant produces tiny spores which can then produce new plants. Example - Plants such as moss and ferns also reproduce by means of spores.
Budding - Budding is a type of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site. The small bulb like projection coming out from the yeast cell is called a bud. Example - Most yeasts reproduce asexually by an asymmetric division process called budding.

Q.9. What is the female reproductive part of a flower?

The female reproductive part of a flower is known as the pistil. It consists of three main components:

• Stigma: The sticky top part that captures pollen.
• Style: The tube that connects the stigma to the ovary.
• Ovary: The part that contains one or more ovules, where the female gametes are produced.

Q.10. What is a node?

A node is a specific part of a plant's stem or branch where a leaf emerges.

Q.11. How fungi grow on bread?

Fungi grow on bread from spores that are present in the air. Here’s how the process works:

• When bread is exposed to air, spores settle on its surface.
• These spores are tiny and can travel long distances.
• Under suitable conditions, such as moisture and warmth, the spores germinate.
• Once germinated, they develop into hyphae, which are the thread-like structures of fungi.
• The hyphae spread and form a network, leading to the visible growth of mould on the bread.

Q.12. What is fertilisation?

The process of fusion of male and female gametes (to form a zygote) is called fertilization.

Q.13. What types of seeds are dispersed by animals?

Some seeds are dispersed by animals, especially spiny seeds with hooks which get attached to the bodies of animals and are carried to distant places. Examples are Xanthium and Urena.

Q.14. How do plants reproduce?

There are several ways by which plants produce their offspring. These are categorised into two types: (i) asexual and (ii) sexual reproduction. In asexual reproduction plants can give rise to new plants without seeds, whereas in sexual reproduction, new plants are obtained from seeds.

Q.15. How does the process of fertilisation take place in flowers?

Fertilisation in flowers occurs through the following steps:

• Pollen grains from the anther land on the stigma of the same flower.
• Each pollen grain develops a pollen tube that grows down through the style.
• The tube reaches an ovule in the ovary, carrying a male gamete.
• The male gamete fuses with a female gamete in the ovule, forming a zygote.
• This fusion process is called fertilisation.
• The zygote then develops into an embryo.

Q.16. What are the vegetative parts of plants?

In vegetative propagation new plants are produced from different vegetative parts such as leaves, stems and roots.

Q.17. State the main difference between asexual and sexual reproduction.

In asexual reproduction plants can give rise to new plants without seeds, whereas in sexual reproduction, new plants are obtained from seeds.

Q.18. What is the function of flowers in plants?

The flowers perform the function of reproduction in plants. Flowers are the reproductive parts of a plant. A flower may have either the male part or the female part or both male and female parts.

Q.19. How plants such as moss and ferns reproduce?

Plants such as moss and ferns also reproduce by means of spores. Spores are asexual reproductive bodies. Each spore is covered by a hard protective coat to withstand unfavourable conditions such as high temperature and low humidity. So they can survive for a long time. Under favourable conditions, a spore germinates and develops into a new individual.

Q.20. Explain what you understand by sexual reproduction.

Sexual reproduction is a biological process that creates new organisms through the combination of genetic material from two parents. This process involves:

• The fusion of male and female gametes.
• Offspring that are genetically distinct from their parents.
• Involvement of structures like flowers in plants, where gametes are produced.

Overall, sexual reproduction contributes to genetic diversity, which is vital for the adaptation and survival of species.