Tag: vernalisation

Questions Related to vernalisation

Potato is _________ for flower formation but _________ for tuberisation.

  1. LDP, SDP

  2. SDP, LDP

  3. LDP, day neutral

  4. SDP, day neutral


Correct Option: A
Explanation:

In the case of potato, it requires more photoperiod to induce flowering. Whereas for the formation of tuber, it requires very less photoperiod. Thus, it is told that potato is LDP for inducing flowering; but SDP for tuber formation. The flower-inducing florigen and tuber-inducing tuberigen signals are functionally exchangeable. Flowering and tuberization are distinct reproduction strategies, both of which involve the sensing of the photoperiod and generation of a signal in the leaves (process called as induction), the subsequent transport of the signal (known as florigen or tuberigen), and the response in a distant organ, the vegetative meristem, or stolon tips (also called evocation).

Cabbage is a biennial plant which produces flowers in the second year of growth. In an attempt to make it flower in a single year, four potted plants (I, II, III, and IV) of cabbage were subjected to different temperatures for several days given in the table.

Potted plant Temperature
I $5^o C$
II $20^o C$
III $30^o C$
IV $25^o C$

Which potted plant will show flowering?

  1. I

  2. II

  3. III

  4. IV


Correct Option: A
Explanation:
The low temperature required for vernalization is usually $0^o-5^oC$. In nature, the plants requiring vernalization are commonly biennials (e.g., cabbage, sugar canes), which complete their life cycle in two years. They germinate and grow vegetatively in the first year and produce flowers in the second year of growth. These plants fulfill their cold requirement during winters. However, such-biennial plants can be made to flower in one growing season by providing low-temperature treatment (i.e., $0^o-5^oC$ temperature) to young plants or moistened seeds.
So the correct answer is 'I'.

Biennials get changed into annuals by

  1. Hormones

  2. Photoperiodism

  3. Grafting

  4. Vernalisation


Correct Option: D
Explanation:
Vernalization is the process by which plant can be induced to flower by exposing it to the prolonged cold or winter. The term was coined by Lysenko in 1928. He stated that certain plants can be made to flower by providing low temperature treatment to young plants or moistened seeds. Biennial plants are changed into annual plants by the process of vernalisation and induces flowering.
Thus, the correct answer is option D.

It has been observed that after-effects of low temperature treatment are helpful in promoting the flowering in certain plants. Through this the vegetative period of plants becomes short and early flowering takes place. This phenomenon is known as

  1. Vernalisation

  2. Florignation

  3. Photoperiodism

  4. Heliotropism


Correct Option: A
Explanation:

Vernalization is the induction of a plant's flowering process by exposure to the prolonged cold of winter, or by an artificial equivalent. After vernalization, plants have acquired the ability to flower, but they may require additional seasonal cues or weeks of growth before they will actually flower. Vernalization is sometimes used to refer to herbal (non-woody) plants requiring a cold dormancy to produce new shoots and leaves but this usage is discouraged. Many plants grown in temperate climates require vernalization and must experience a period of low winter temperature to initiate or accelerate the flowering process. This ensures that reproductive development and seed production occurs in spring and winters, rather than in autumn. The needed cold is often expressed in chill hours. Typical vernalization temperatures are between 5 and 10 degrees Celsius (40 and 50 degrees Fahrenheit).

So the correct option is 'vernalisation'.

Which of the following hormones can replace vernalisation?

  1. Auxin

  2. Cytokinin

  3. Gibberellins

  4. Ethylene


Correct Option: C
Explanation:

Vernalization is the process by which plant can be induced to flower by exposing it to the prolonged period of low temperature or cold. After this, plants show quicker flowering. Gibberellic acid is a plant hormone which helps in growth of stem. It also brings about the rapid flowering in plants.

Thus, the correct answer is option C.

Low temperature is required in apple for a duration of

  1. 800 hours

  2. 400 hrs

  3. 200 hrs

  4. 100 hrs


Correct Option: A
Explanation:

Apple is able to grow in low temperature the earlier stages have less tolerance of lower temperature than the later stages and it requires around 800 hours for growth.

So the correct option is '800 hours'

The phenomenon which shortens vegetative period and hastens flowering is

  1. Etiolation

  2. Vernalisation

  3. Photoperiodism

  4. Parthenocarpy


Correct Option: B
Explanation:

Etiolation is a condition in which plant is grown in the partial or complete absence of light. The leaves are tiny and yellow in color. Vernalization is the process by which plant can be induced to flower by exposing it to the prolonged cold or winter. It shortens the vegetative period and hastens the flowering. Photoperiodism is the phenomenon in which various physiological reactions like flowering response to the relative length of day and night.

Thus, the correct answer is option B.

Nitrate reductase enzyme forms?

  1. $N _2$

  2. Amino acids

  3. $NCT _2$

  4. $NO^- _3$


Correct Option: A

Citrus canker is caused by.

  1. Alter aria citric

  2. Xanthamonas citric

  3. Diaporthe citric

  4. Phytophthora citrophthora


Correct Option: A

The compound pollen grain, massula is characteristic of ____________.

  1. Papilionaceae

  2. Caesalpiniaceae

  3. Mimosaceae

  4. Proteaceae


Correct Option: A