Tag: cross pollination

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Questions Related to cross pollination

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

Maturation of stigma and anthers at different times in the same flower is

  1. Heterostyly

  2. Dichogamy

  3. Dicliny

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

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.

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.
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.
So, the correct answer is B.

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

Dichogamy is

  1. Placement of anthers and stigmas at different levels

  2. Inability of the pollen to germinate on the stigma of the same flower

  3. Occurrence of barrier between anther and stigma of the same flower

  4. Maturation of anthers and stigmas at different times
Reveal answer Fill a bubble to check yourself
D 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).

While placement of anthers and stigma at different levels is called Heterostyly, inability of pollen to germinate on the stigma of the flower is called self-incompatibility and the occurrence of a barrier between anther and stigma of the same flower is called Herkogamy.
So, the correct answer is D.

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

In the light of Neo-Darwinism, which one of the following offers the greatest advantage to a population invading a new ecological niche?

  1. Outbreeding

  2. Apomixes

  3. Vegetative propagation

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

Outbreeding increases genetic variation within a population, which is crucial for adaptation and survival when invading a new ecological niche. Inbreeding, apomixis, and vegetative propagation generally reduce genetic diversity.

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

With reference to mass selection of crop plants, consider the following statements.
a. Mass selection has been more commonly used for the improvement of cross-pollinated crops than the single plant selection.
b. The purpose of mass selection is to increase the frequency of superior genotypes in the population.
c. This method of breeding has been very effective in improving characters governed by many genes.
Which of the statements given are correct?

  1. $1, 2$ and $3$
  2. $1$ and $2$
  3. $1$ and $3$
  4. $2$ and $3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Mass selection is effective for cross-pollinated crops, aims to increase the frequency of favorable alleles, and is useful for traits controlled by multiple genes (polygenic traits). All three statements are standard principles of plant breeding.

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

Dichogamy refers to _________________.

  1. Male and female sex organs maturing at the same time

  2. Male and female sex organs maturing at different times

  3. Male sterility

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

Dichogamy refers to a reproductive strategy in plants where the male and female reproductive organs mature at different times. It can be protandry (male organs mature first) or protogyny (female organs mature first), which effectively promotes cross-pollination.

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

Match column I with column II and select the correct option from the given codes.

Column I Column II
A. Monoecious (i) Primula
B. Dioecious (ii) Maize
C. Cleistogamous (iii) Date palm
D. Heterostyly (iv) Commelina

  1. A-(iii), B-(ii), C-(iv), D-(i)

  2. A-(ii), B-(iii), C-(iv), D-(i)

  3. A-(ii), B-(iii), C-(i), D-(iv)

  4. A-(i), B-(ii), C-(iii), D-(iv)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Monoecious plants are those that have the male and female flower on the same plant. An example is maize.

Dioecious plants are those that have the male and female flowers on two different plants. Example is date palm.
Heterostyly is a measure taken by the plant to prevent inbreeding or self -fertilization. In this type of plants, they have styles of different length related to stamen in the flower of the individual plant so the pollen of the same flower cannot fertilize the stigma. Occurs in Primula vulgaris
Cleistogamy is a type of self-pollination in a certain type of plants which can take place when there are flowers which do not open and self-pollination takes place inside of them. It is most widespread in the grass family. Commelina also shows cleistogamy.
So, the correct option is 'A-(ii), B-(iii), C-(iv), D-(i)'

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

The features where stamens and stigma mature at different times favouring cross pollination is known as?

  1. Dichogamy

  2. Herkogamy

  3. Autogamy

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

Herkogamy is shown by hermaphroditic angiosperms to reduce sexual interference between anthers and female stigma function. Autogamy, or self-fertilization, refers to the fusion of two gametes that come from one individual. cleistogamy is self-fertilization that occurs within a permanently closed flower. Dichogamy means when stamens and stigma mature at different times favouring cross-pollination. 


So, 'the correct option is 'Dichogamy'

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

Allogamy is best favoured by ...............

  1. Cleistogamy

  2. Dicliny

  3. Homogamy

  4. None above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In plants, allogamy is used specifically to mean the use of pollen from one plant to fertilize the flower of another plant and are usually synonymous with the term cross fertilization , though the latter can be used more specifically to mean pollen exchange between different plant strains or even different individuals. Allogamy is best favoured by Dicliny. Dicliny refers to unisexual flowers. This is of two types: monoecy and dioecy.