Rajasthan Board RBSE Class 8 Science Chapter 6 Reproduction in Plants
RBSE Class 8 Science Reproduction in Plants Intext Questions and Answers
Page No 60.
Have you ever think, why only neem plants develop under a neem tree.
Why a Goat gives birth to on of its kind ?
in all organisms gene structure is present which is fixed in every organism. On the basis of law of heredity this fixed structure transmit through reproduction from one generation to the next by which every organism gives birth to similar trait progeny. This is the reason that seeds obtained from margosa plant will develop into margosa plant or goat give birth to a lamb similar to it.
Pages No 63-64.
Observe the Dhatura flower and fill the following table –
Page No 66.
Do all the fruits have seeds? Which fruits do not have seeds?
Most of the fruits have seeds but fruits obtained from parthenocarpy do not have seeds, example – Banana, Grapes. etc.
RBSE Class 8 Science Reproduction in Plants Tex Book Questions and Answers
Mark the correct option:
Vegetative reproduction is found in –
Fusion of male and female gametes is called-
Unisexual flowers is –
Bisexual flower is –
Fill in the blanks:
- Fern and moses reproduces by __________.
- To produce of __________ their own kind is called .
- __________ is formed by the fusion of male and female gametes.
- In __________ pollens from the anthers reaches the stigma of the same flower.
- Asexual reproduction
- progeny, reproduction
Match following (Board paper)
Short answer type Questions:
Describe the various processes of asexual reproduction. Give example of each.
In plants there are following methods of asexual reproduction –
1. Budding –
In this type of reproduction a small bulging is develop from the body of the plant. it is called bud as it is found in yeast cell. The bud grows in size gradually and after being detached from the parent cell develops into a new yeast cell.
2. Fragmentation –
This type of reproduction found in algae. These algae grow in ponds in form of green slippery scum, When algae grow then multiply quickly by fragmentation and each fragment grow to develop into a new algae. Example Spirogyra.
3. Spore formation –
This type of reproduction found in fungi. Fungi is also called ‘phafund’. It can be seen on moist bread. It forms cotton like net. It contains the black brown coloured sporangia in which spores are present. When these spores are released from sporangia, they, float in air and reach to long distance due to light in weight. Each spore forms a tough wall around itself to protect itself from adverse conditions like high temperature and low moisture. When favourable conditions return the spore germinates and develop into new fungal hyphae. Example – Mucor, Rhizopus.
Differentiate between unisexual and bisexual flower.
Unisexual Flower –
Those flowers, which have either stamens, or pistil in them are known as unisexual flowers.
Watermelon, Pappaya and Maize.
Bisexual Flower –
Those flowers which have both stamens and pistil are called bisexual flowers.
Mustard, China rose and Datura.
Differentiate between self pollination and cross pollination?
To reach pollen grains by any means at stigma is known as pollination. Write a difference between self-pollination and cross-pollinations with suitable examples?
When pollen grains are transferred from the pollen sacs to the stigma of the same flower or the stigma of another flower born on the same plant, then this type of pollination is called self pollination.
Example – Pea, Tomato.
Cross Pollination –
When pollen grains are transferred from the pollen sac of a flower to the stigma of a flower born on different plant of the same species, the pollination is called cross-pollination.
Example – Rose. Poppy.
Draw a Labelled diagram of a flower.
Labelled diagram of a flower –
Explain parthenocarpy with an example.
Parthenocarpy – When the ovary directly develops into fruit without fertilization the process is know as parthenocarpy. The fruits formed in this manner do not have seeds. Example – Banana. Grapes.
Write the 3 Jaws of inheritance given by mendel.
Mendcl gave the following three laws of heredity –
- Law of dominance.
- Law of segreggation.
- Law of independent assortment.
Long answer type Questions:
DilTerentlate between sexual and asexual reproduction.
Differences between sexual and asexual reproduction
Explain process of sexual reproduction with diagram.
Sexual reproduction –
This type of reproduction takes place in well developed plants. In the flower male reproductive organs are the androecium and female reproductive organs are the gynoecium, which may he present in one flower or in different flowers.
Female Reproductive Organ –
The gynoecium consist three parts, which are respectively called stigma, style and ovary. Ovules are present inside the ovary and each ovule consist inside an egg ccli.
Male Reproductive Organ –
the androecium Consist another lobe which develop pollen grains. In the pollen grain male gamete is formed. A single pollen sac consist many pollen grains.
By pollination, the pollens reach the stigma of gynoecium and gets germinated. A pollen tube arises from the pollen and reaches the ovule in the ovary through the style. The male nuclei present in the pollen tube fuses with the egg cell present in the ovule. Thus the process of fusion of male nucleus and female nucleus is called fertilization. Fertilization results in the diploid zygote.
This zygote further divides to form an embryo. Thus after fertilization, seed develops from the ovule and fruit develops from the ovary. When the fruit is used up, the seeds become free and germinates to form a new plant. The process to produce offsprings in this manner in the developed plants (angiosperm) is called sexual reproduction. In angiosperms. the endosperm is triploid.
Explain the various processes of vegetative reproduction with examples.
Vegetative Reproduction – The process in which except seed any part of the plant like root, stem or leaf may develop into new plant called vegetative reproduction. The plants formed by vegetative reproduction are similar in characters to their parent plants. These are known as clone. Methods of Vegetative Reproduction –
1. From underground stem –
Take a potato and observe. There are some raised structure in the depression which are called eye. Cut these portions, having eyes. Dig hole in soil and plant these pieces. Cover these small pits with soil and regularly water II. After few days new plant emerging from the eyes of potato can he seen. In this way without seed new plant can be develop.
2. Bryophyllum (Path archata) –
In this buds are found in the notches of leaves. When these buds are SOWfl or if falls on moist soil then each bud develops into a new plant.
3. Cactus –
In cactus stern detaches from plant and develop into a new plant.
4. Dahlia –
New plants are formed by roots.
5. From cut stem of rose –
Cut a branch of rose plant from node. A node is that part of stem or branch from which leaves arise. This 10-12 cm long part of branch is called cutting. Cut this obliquely and plant it in soil and regularly water it. After few days from this cutting new branches emerge out and gradually it would develop into a new plant of rose.
RBSE Class 8 Science Reproduction in Plants Important Questions and Answers
Asexual reproduction takes place by budding in –
Pollen grains are found –
(a) In ovary
(b) In anther lobe
(c) In sepals
(d) in petals
(b) In anther lobe
Vegetative reproduction in Bryophyllum takes place –
(a) from stem
(b) from root
(c) from leaf
(d) from above all
(c) from leaf
The method of asexual reproduction in spirogyra –
(c) Spore formation
The zygote formed after fertilization is –
Diploid zygote is formed by the fusion of male and female gamete. This process is called –
7. Stored potatos develop buds on them. Such type of Reproduction is called –
(a) Sexual Reproduction
(b) Vegetative Reproduction
(c) Asexual Reproduction
(b) Vegetative Reproduction
Fill in the blanks:
- In cactus _____ detaches from plant develop into a new plant. (stem / leaf)
- In asexual reproduction new organisms are produced _____. (single parent / separate parent)
- Essential whorl of flower help in _____. (transpiration process / reproduction process)
- When ovary takes part in formation of fruit then it is called _____. (True fruit / False fruit)
- single parent.
- reproduction process,
- True fruit.
True / False:
- Who has taken the birth on this earth his death is fixed.
- We cant get the plant from eye containing
- In Dahalia new plants are formed by roots.
- The outermost whorl of a flower is corolla.
- The gynoecium consist stigma, style and ovary.
- Cross pollination found in tomato plant.
Math the Column –
Match the following correctly:
Match the following correctly:
Very Short Answer Type Questions:
There are two types of flower. Give an example of each unisexual and bisexual flowers.
- Example of unisexual flower – Papaya
- Example of bisexual Flower – Mustard.
What is reproduction?
The process of production of same type of off springs by living organisms is called reproduction.
Define vegetative reproduction.
Vegetative reproduction – The process of production of new plants from vegetative parts of the plant is called vegetative reproduction. It means the new plant do not develop from seeds but develop from vegetative parts like root, stem and leaves.
What is the medium of vegetative reproduction in rose plant?
In rose plant vegetative reproduction takes place by cutting or cuim.
When in a flower out of androeciurn or gynoecium only one reproductive organ is present then what we call such flower?
When a flower have either androecium or gynoecium in them, then such flower is known as unisexual flower.
Give any one example of bisexual flower.
Example of bisexual flower ¡s china rose and mustard.
Where the female reproductive that is gynoecium present in the flower?
Female reproductive organ or gynoecium present ¡n the centre of the flower.
In which part of gynoecium the ovules are situated?
Ovule is situated in the ovary of gynoecium.
After fertilization in which structure ovule is changed?
After fertilization ovule . is changed in seed.
What is pollination?
The transfer of pollen grains from The pollen sac to the stigma of the flower by any means of agent is called pollination.
What is meant by heredity?
The process of transmission of herediary characters from one generation to the next is called heredity.
Who is the father of genetics?
Scientist Gregor John Mendel is the father of genetics.
Name the various parts of gynoecium.
Short Answer Type Questions:
Complete the following table on the basis of observation of datura flower –
What are the methods of reproduction in plants? Write name. What are the benefits of vegetative reproduction? Write.
What do you understand by vegetative reproduction? Write four benefits of vegetative reproduction.
The process of developing new plant from the vegetative part of the plant rather than seed is called vegetative reproduction. Following are the methods of reproduction in plants –
- Vegetative reproduction
- Asexual reproduction
- Sexual reproduction
Benefits of vegetative reproduction –
- Plants develop in lesser time.
- Flowers and fruits are obtained in lesser time.
- The new plants are obtained from a single parent.
- Parental characters are conserved as the plants grown are genetically identical.
- The productivity of plants obtained by vegetative reproduction is more. .
- What is the name of common bread fungi?
- What is called the small thread like structure of bread fungi?
- What is called, the small knob like structure present on tip of the threads on bread fungi?
- What is inside the knob like structure of bread fungi?
- Scientific name of common bread fungi is Rhizopus.
- The small, thread like structure of bread fungi is called fungal hyphae.
- The small, knob like structure present on tip of threads on bread fungi is called sporangia.
- Spores are present in sporangia of bread fungi.
Draw a labelled diagram of vertical section of datura flower.
Labelled diagram of vertical section of datura flower –
What are the functions of flower in plants? Describe.
Following are the functions of flower –
- To hear the male and female reproductive organs.
- Development of male and female gametophyte in reproductive organs and to form the male and female gametes.
- To complete the process of fusion or fertilization of gametes of opposite sex.
- Formation of fruits and seeds.
On the basis of your knowledge write the names of following –
- Largest flower
- Smallest flower
- largest seed
- Smallest seed.
- Largest flower – Rafflesia
- Smallest flower – Woiffia
- Largest seed – Lodoicea
- Smallest seed – Orchid.
Where the fruit is formed in the flower? How many types they are?
Fruit – Fruit formation takes place after fertilization in flower. Ripe ovary is called fruit. Wall of ripe ovary makes the fruit wall.
Mainly fruits are of two types –
- True fruit (Factual fruit)
- False fruit (Pseudocarp)
Why Mendel selected the pea plant for his heriditical experiments?
Mendel selected the pea plant for his hereditical experiment due to following reasons –
- Pea plant have clear cut visible seven contrasting characters.
- Life duration of pea plant is short.
- The construction of flower of pea plant is such that self pollination and cross pollination can easily be done according to necessity.
How the reproduction is helpful In making the permanent existence of a species?
Every organism which has taken the birth on this earth, his death is fixed, whether a plant or animal. Therefore, to maintain the existence of its species each living organism produces offspring like it. The process of production of same type off springs by living organisms is called reproduction. In living organisms this process is continuous generation, for the perpetuation (maintenance of continuity and existence) of the species.
Long Answer Type Questions:
Write the function and speciality of different parts of the flower.
Functions and speciality of different parts of flower
What do you mean by pollination? What are the types? Explain diagramatically.
Pollination – Pollen grains reach from one place to the other by the medium of wind, water, insects or by animals. Pollen grains stick to the body of insects when they sit in the a flower. When these insects visit other flowers than these pollen grains fall on the stigma of that flower. The transfer of pollen grains from the pollen sac to the stigma of the flower by any means of agene is called pollination. On the basis of pollination process they are of two types –
1. Self-pollination – When pollen grains are transferred from the pollen sac to the stigma of the same flower or the stigma of another flower born on the same plant, then this type of pollination is called self-pollination. Example – Pea, Tomato.
2. Cross-pollination – When pollen grains are transferred from the pollen sac of a flower to the stigma of a flower born on different plant of the same species, the pollination is called cross – pollination. Example – Rose, poppy, etc.
What is parthenocarpy? Where the fruit is formed in the plant? In how many groups fruits divided? Write.
Parthenocarpy – When the ovary directly develop into fruit without fertilization, the process is known as parthenocarpy. The fruits formed in this manner do not have seeds. Example – Banana, Grapes, etc. Formation of Fruit – Fruit is formed in the ovary or a mature ovary is called fruit. Fruits are of two types –
1. True Fruit – Fruit is formed only from ovary, as mango.
2. False Fruit – Apart from ovary some other parts of the flower like thalamus, sepals etc. takes part in formation of fruit, example pear, apple, in these fruits thalamus forms the main edible part, so they are false fruit. Groups of Fruit – The fruit have been divided into three groups –
(i) Simple Fruit –
When a single fruit is formed from the ovary of a flower, such fruits are called simple fruit. Example – Mango, wheat.
(ii) Aggregate Fruit –
When many fruits develop from the multicapetilary, apocarpous gynoecium of a flower, but remain in the form of a group (or aggregate), the fruit is known as aggregate fruit, like strawberry.
(iii) Composite Fruit –
When all the flowers of an inflorescence participate in formation of a fruit, such is known as composite fruit, like – Muliberry, custard apple etc.
What is meant by heredity? Prepare a table of contrasting pairs of characters of pea plant selected by Mendel.
Heredity – The process of transfer of hereditary characters from one generation to another generation is called heredity. Table – List of Contrasting pair Characters