Tag: cross pollination

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Questions Related to cross pollination

Multiple choice biology pollination, fertilization and development of endosperm and embryo types of pollination cross pollination pollination and its types

Above ground cleistogamous flowers are formed late in the season in

  1. Balsam

  2. Viola

  3. Oxalis

  4. All the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Cleistogamy is the phenomenon, where flowers never open and in such flowers, only self-pollination occurs within the bud (unopened flower). Bisexual flowers which do not open at all are called cleistogamous. In such flowers, anthers and stigma lie close to each other. When the anthers dehisce in the flower buds, pollen grains come in contact with the stigma and pollination occurs. Example of Cleistogamous flowers is Viola. Viola has two kinds of flowers, Chasmogamous flowers that are formed on the upper branches in early season, which are pollinated by insects and Cleistogamous flowers that are formed above the ground late in the season.
So, the correct answer is B.
Multiple choice biology pollination, fertilization and development of endosperm and embryo types of pollination cross pollination pollination and its types
Cleistogamy does not require anthesis because

  1. No pollination agent is required

  2. It assures heterozygosity

  3. It allows xenogamy

  4. It favours insect pollination
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Anthesis is the flowering period in which flowers are fully opened.
Cleistogamy is the phenomenon, where flowers never open and in such flowers, only self-pollination occurs within the bud (unopened flower). Bisexual flowers which do not open at all are called cleistogamous. In such flowers, anthers and stigma lie close to each other. When the anthers dehisce in the flower buds, pollen grains come in contact with the stigma and pollination occurs. Cleistogamous flowers are not dependent on external agencies for pollination.  Since, Cleistogamous flowers have self pollination and don't depend on pollination agents, anthesis is required in them as these flowers do not open at all.
So, the correct answer is A.
Multiple choice biology pollination, fertilization and development of endosperm and embryo types of pollination cross pollination pollination and its types

Both autogamy and geitonogamy cannot occur in

  1. Papaya

  2. Cucumber

  3. Castor

  4. Maize
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Autogamy is the kind of self pollination in which pollens are transferred from the anther to the stigma of the same flower. Geitonogamy is the kind of self pollination in which pollens are transferred from the anther of one flower to the stigma of another flower on the same plant.
Papaya is a dioecious plant i.e. it has male and female flowers on separate plants. Hence, neither Autogamy nor Geitonogamy can occur. So, the correct answer is A.
Multiple choice biology pollination, fertilization and development of endosperm and embryo types of pollination cross pollination pollination and its types

Match the columns and choose the correct combination.

I II
(a) Cleistogamy (m) Insect pollination
(b) Geitonogamy (n) Bud pollination
(c) Entomophily (o) Pollination between flower of the same plant
(d) Xenogamy (p) Wind pollination
(q) Cross pollination

  1. a-m, b-q, c-n, d-o

  2. a-n, b-o, c-m, d-q

  3. a-q, b-p, c-o, d-n

  4. a-o, b-m, c-q, d-n
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
•Cleistogamy is the phenomenon, where flowers never open and in such flowers, only self-pollination occurs within the bud (unopened flower).
•Geitonogamy is a type of self pollination in which pollen are transferred from the anther of one flower to the stigma of another flower of the same plant.
•Entomophily is the pollination of flowers by means of insects.
•Xenogamy is the cross pollination between the flowers of different plants.
Hence, the correct match is:
a-n, b-o, c-m, d-q
So, the correct answer is B.
Multiple choice biology pollination, fertilization and development of endosperm and embryo types of pollination cross pollination pollination and its types

Which one of the following is one of the characteristics of self-pollinated flowers ?

  1. Flowers are large and showy

  2. Flowers remain closed and do not open

  3. Stigma and anthers mature at the same time

  4. Pollen is produced in very large quantities
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Self-pollinated flowers remain closed and don't open allowing maximum time for the mature stamens and pistils to exchange and receive the gametes. 

So, the correct option is 'Flowers remain closed and do not open'.

Multiple choice biology pollination, fertilization and development of endosperm and embryo types of pollination cross pollination pollination and its types

Which of the following features are mostly observed in self pollinating flowers?

  1. Inconspicuous flowers

  2. Presence of nectaries

  3. No fragrance

  4. Short style

  5. Versatile anthers
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The inconspicuous flower is a flower that is small, not showy and difficult to see. They are observed in self-pollinating flowers.

So, the correct option is 'Inconspicuous flowers'.

Multiple choice biology pollination, fertilization and development of endosperm and embryo types of pollination cross pollination pollination and its types

Which of the following statement is NOT correct?

  1. Pollen germination and pollen tube growth are regulated by chemical components of pollen interacting with those of the pistil.

  2. Some reptiles have have also been reported as pollinators in some plant species.

  3. Pollen grains of many species can germinate on the stigma of a flower, but only one pollen tube of the same species grows into the style.

  4. Insects that consume pollen or nectar without bringing about pollination are called pollen/nectar robbers.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pollen grains of other species are not compactable and do not germinate on the stigma of the flower of different species.

So, the correct option is 'Pollen grains of many species can germinate on the stigma of a flower, but one pollen tube of the same species grow into the style'.

Multiple choice biology pollination, fertilization and development of endosperm and embryo types of pollination cross pollination pollination and its types

Select the mismatched pair.

  1. Storage of pollen grains - $196^o$C

  2. Pollen allergy - Carrot grass

  3. Chasmogamous flowers - Exposed anthers and stigmas

  4. Xenogamy - Self pollination
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Xenogamy or cross pollination is the transfer of pollen grains from the anther of one flower to the stigma of a genetically different flower. Cross pollination is performed with the help of an external agency.

Multiple choice biology pollination, fertilization and development of endosperm and embryo types of pollination cross pollination pollination and its types

Even in absence of pollinating agents seed-setting is assured in.

  1. Commelina

  2. Zostera

  3. Salvia

  4. Fig
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Commelina bears aerial, chasmogamous (stigma and anthers exposed to pollinating agents), insect pollinated flowers and underground cleistogamous flowers. Cleistogamous flowers are bisexual flowers which never open. In such flowers, the anther and stigma lie very close to each other. When anther dehisce in the flower buds, pollen grains come in contact with the stigma of the same flower i.e, autogamy occurs. So, these flowers produce assured seed set, even in the absence of pollinators.

So, the correct option is 'Commelina'.

Multiple choice biology pollination, fertilization and development of endosperm and embryo types of pollination cross pollination pollination and its types

How can plants prevent self pollination?

  1. Stamen and pistil mature at different times.

  2. Plants should develop bisexual flowers.

  3. Pistil should have increased receptivity for pollens from same plant.

  4. All of the above.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • There are several methods to prevent self-pollination in plants. Bisexual flowers show self-pollination. 
  • Chances of self-pollination increases when pistil has increased receptivity for pollen from the same plant. Self-pollination occurs in flowers where the stamen and carpel mature at the same time. 
  • Hence, to prevent self-pollination, stamen and pistil must mature at different times. 

Thus, the correct answer is option A.