Tag: pollination and fertilization

Quizzes (6) Questions (136)

Questions Related to pollination and fertilization

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

Which one of the following is not a device to promote cross-pollination?

  1. Herkogamy

  2. Dichogamy

  3. Cleistogamy

  4. Heterostyle
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cleistogamy is not a device to promote cross-pollination as the flowers remain closed and they promote self-pollination. For example, Balsam, Oxalis and Viola anthers dehisce inside closed flowers. 

Herkogamy, dichogamy and heterostyly are the devices which promote cross-pollination. Herkogamy is a mechanical device to prevent self-pollination. For example in Pansy, stigma lies inside a flap.
In dichogamy, anthers and stigma mature at different times which ensures cross-pollination. When anthers mature earlier, it is known as protandry as in sunflower and when stigmas mature earlier it is known as protogyny as in Gloriosa.
In heterostyly, there are 2 or 3 different types of flowers with different heights of stamens and stigmas which prevent self-pollination as in jasmine. 
Thus, the correct answer is option C. 

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

The pollen of apple germinates easily on the stigma than the pollen of another flower. This tendency is known as

  1. Prepotency

  2. Self sterility

  3. Dichogamy

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

In some plants when the stigma receives pollen from the same flower as well as from the other flower simultaneously, the foreign pollen germinates vigorously and fertilize the ovule.

So the correct option is 'Prepotency'.

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

Which of the following plants shows the tendency of prepotency?

  1. Guava

  2. Apple

  3. Grapes

  4. Both B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Prepotency is the phenomenon in which Pollen grains of another flower of the same species germinate more rapidly over the stigma, in comparison to the pollen grains of the same flower. For example Apple, Grape, etc.

So the correct answer is D.

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

Faster and better growth of pollen from other plants than the pollen from the same plant is?

  1. Self incompatibility

  2. Dichogamy

  3. Monocliny

  4. Prepotency
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Self-incompatibility is the widespread mechanism in flowering plants which prevents the inbreeding and promotes the outcrossing. Dichogamy is the mechanism when the stigma and anther mature at different times.  Monocliny i.e. Bisexuality is applicable for bisexual flowers. Pollen prepotency is the mechanism when the pollen of a different flower germinates faster than of the same flower thus preventing autogamy.

Thus, the correct option is D.

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

Barrier to avoid self pollination between stamens and pistils is

  1. Heterostyly

  2. Herkogamy

  3. Dichogamy

  4. Dicliny
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Plants have adapted various ways to prevent self pollination, such as:
Heterostyly- It is the occurrence of 2-3 types of flowers within the same plant and such flowers have the difference in length of styles and stamens.
Herkogamy- It is the condition in which the flower structure is such that even being bisexual, the pollen grains fail to reach the stigma. In some flowers, a mechanical barrier exists between the compatible pollen and stigma so that self pollination is not possible. Sometimes, there is a hood like covering that covers the stigma.
Dichogamy- It is the condition when the anther and stigma mature at different times. Either anthers dehisce before the stigma becomes receptive (called protandry) or stigma becomes receptive before anthers dehisce (called protogyny).
Dicliny- It is the presence of only one kind of reproductive whorl in a flower. It is also called unisexuality.
Therefore, from all of the above measures, herkogamy is the one in which self pollination is prevented by floral barriers between stamens and pistils.
So, the correct answer is B.
Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types
Dicliny is found in

  1. Calotropis

  2. Cucurbita

  3. Crotalaria

  4. Pisum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Dicliny is the presence of only one kind of reproductive whorl in a flower. Dicliny is thus called unisexuality. In dicliny, a plant may be monoecious i.e. both male and female flowers are borne on the same plant or the plant may be dioecious i.e. male and female flowers are borne on different plants. Among all the options given in the question, Calotropis, Pisum and Crotalaria have bisexual flowers. But, Cucurbita is monoecious plant. Thus, Cucurbita exhibit dicliny. So, the correct answer is B.
Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

Nontransfer of pollen from anther to stigma of the same flower due to a mechanical barrier is

  1. Dichogamy

  2. Herkogamy

  3. Heterostyly

  4. Cleistogamy
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Dichogamy- It is the condition when the anther and stigma mature at different times. Either anthers dehisce before the stigma becomes receptive (called protandry) or stigma becomes receptive before anthers dehisce (called protogyny).

Herkogamy- It is the condition in which the flower structure is such that even being bisexual, the pollen grains fail to reach the stigma. In some flowers, a mechanical barrier exists between the compatible pollen and stigma so that self pollination is not possible. Sometimes, there is a hood like covering that covers the stigma.
Heterostyly- It is the occurrence of 2-3 types of flowers within the same plant and such flowers have the difference in length of styles and stamens.
Cleistogamy- It is a phenomenon, where flowers never open and in such flowers, only self-pollination occurs within the bud (unopened flower). 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. 
Thus, from all the options given in question, mechanical barrier to prevent the transfer of pollen grains from the anther to the stigma is found in Herkogamy.
So, the correct answer is B.

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types

Which is not a correct explanation of cross pollination?

  1. Pollen grains of male flowers are transferred to stigma of female flowers

  2. Pollen grains are transferred from one flower to another flower of another plant of the same species

  3. Pollen grains are transferred from one flower to another flower situated on the same species

  4. Pollen grains of one flower are transferred to the stigma of the same flower
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cross-pollination involves the transfer of pollen from one flower to another. Transferring pollen to the same flower is self-pollination, not cross-pollination.

Multiple choice botany pollination and fertilization types of pollination cross pollination pollination and its types
Gloriosa superba exhibits

  1. Heterostyly

  2. Self sterility

  3. Herkogamy

  4. Cleistogamy
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
In Gloriosa superba, flower structure is such that inspite of being bisexual the pollen grains are not able to reach the stigma. The anther dehisce outwardly at a distance from the stigma and therefore, pollen can't fall on the stigma and self-pollination is prevented. This adaptation by Gloriosa to prevent self-pollination by means of floral barriers is called Herkogamy.
So, the correct answer is C.