Tag: cross pollination

Questions Related to cross pollination

Two plants showing morphological similarities were cross pollinated. But after the mating progeny formation was absent. So the two plants must be considered as?

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

  1. Same biological species

  2. Allopatric species

  3. Different biological species

  4. Same taxonomic species

Show answer
Correct Option: A

In dimorphic flowers, cross pollination is contrived by 

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

  1. Dicliny

  2. Dichogamy

  3. Herkogamy

  4. Heterostyly

Show answer
Correct Option: D
Explanation:

Heterostyly is a form of polymorphism. In this condition, styles are of different lengths relative to the stamens in flowers. This reduces self pollination and promotes cross pollination. Primrose plants shows heterostyly.

Thus, the correct answer is option D.

The phenomenon of male and female structures maturing at two different 

times is ...............

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

  1. Dichogamy

  2. Heterostyly

  3. Hekrogamy

  4. Dioecious

Show answer
Correct Option: A
Explanation:

Dichogamy : It is defined as the condition in some flowering plants, in which the pistils and stamens mature at different times, thus preventing self-pollination. In other terms, it is defined as the maturation of male and female parts of a flower at different times, preventing automatic self-pollination.

Non-transfer of pollen from anther to stigma of the same flower due to a physical barriers is called as 

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

  1. Dichogamy

  2. Herkogamy

  3. Heterostyly

  4. Homogamy

Show answer
Correct Option: B
Explanation:

Herkogamy - common strategy employed by hermaphroditic angiosperms to reduce sexual interference between male and female function. It differs from other such strategies by supplying a spatial separation of the anthers and stigma.

When the pollen grains are not transferred from anthers to the stigma in flower due to the barrier or fence, it is referred or when some natural barrier exists between androecium and gynoecium to check self pollination, it is known as _____________.

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

  1. Heterostyly

  2. Herkogamy

  3. Dichogamy

  4. Cleistogamy

Show answer
Correct Option: B
Explanation:

Herkogamy is a probable strategy applied by hermaphroditic angiosperms to reduce sexual interference between male and female function. It varies from other such strategies by supplying a spatial parting of the anthers and stigma.

Heterostyly is referring to the condition of having styles of different lengths, These are relative to the stamens in the flowers of various individual plants for reducing self-fertilization.

Dichogamy is the condition in which the male and female reproductive organs of the flower mature at different times to ensure that self-fertilization does not occur.

Cleistogamy refers to the self-fertilization which occurs within a permanently closed flower.

So option B is correct.

Despite high level of heterozygosity, the progeny derived from seed of a cross pollination plant was found to be completely uniform. One reason for this may the phenomenon of 

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

  1. Parthenocarpy

  2. Apomixis

  3. Induced mutation

  4. Polyploidy

Show answer
Correct Option: B
Explanation:

Because apomixis is a abnormal kind of sexual reproduction in which egg or other cells associated with egg (synergids, antipodals etc) develop into embryo without fertilization and with or without meiosis.

Heterostyly is show by

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

  1. Primula

  2. Mirabilis

  3. Helianthus

  4. China rose

Show answer
Correct Option: A
Explanation:

In heterostyly condition , stamens style and stigma are of different heights e.g., Primula , Oxalis , Linum etc .

What name has been assigned to the genus produced by a cross between cabbage and radish

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

  1. Secale

  2. Bursa pastor

  3. Lysogenicophyll

  4. Raphano brassica

Show answer
Correct Option: D
Explanation:

Raphanobrassica , Triticale and Bromato are some  intergeneric hybrids. Raphanobrassica (Cabbage) is the result of distant cross between Raphanus (Radish) and Brassica (Cabbage). 

Allogamy is favoured by

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

  1. Homogamy

  2. Cleistogamy

  3. Monocliny

  4. Dicliny

Show answer
Correct Option: D
Explanation:
Allogamy, also known as cross pollination, is the transfer of pollen grains from the anther of one flower to the stigma of another flower borne on a separate plant.
Dicliny is the presence of only one kind of reproductive whorl in a flower. It is also called unisexuality.
A plant may be monoecious i.e. male and female flowers are present on the same plant. In such cases, both cross pollination and self pollination can occur.
Or the plant may be dioecious i.e. male and female flowers are present on different plants. In such cases, only cross pollination can occur. Thus, dicliny favours allogamy or cross pollination.
So, the correct answer is D.

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

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

  1. Herkogamy

  2. Dichogamy

  3. Cleistogamy

  4. Heterostyle

Show answer
Correct Option: C
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.