Tag: life span

Questions Related to life span

In the first year of a biennial plant, .......... grows then it enters a period of dormancy over the cold months

  1. Leaves

  2. Stem

  3. Roots

  4. All of the above


Correct Option: D

A monocarpic palm is

  1. Areca

  2. Borassus

  3. Corypha

  4. Calamus

  5. Elaeis


Correct Option: C
Explanation:

Corypha is a monocarpic palm. It belongs to Arecaceae family (family of palms) which only flowers once in its lifetime.

So, the correct option is 'Corypha'.

A perennial plant differs from biennial in

  1. Having underground perennating structure

  2. Having asexual reproductive structures

  3. Being tree species

  4. Not dying after seasonal production of flowers


Correct Option: D
Explanation:

Perennial plants are plants which can live for more than two years whereas a biennial plant is a flowering plant that takes two years to complete its biological lifecycle. So the difference between perennial plant and biennial is that perennial plants do not die after seasonal flower production.

So, the correct option is D.

Which of the following organisms breeds only once in life time

  1. Bamboo

  2. Oysters

  3. Pelagic fishes

  4. Birds

  5. Mammals


Correct Option: A
Explanation:
Bamboo flower only once in their life, generally after 50 - 100 years. They produce a large number of fruits and die. They rely on seed to perpetuate themselves. 
Oysters usually reach maturity in one year. 
Birds mate only once per year.
Mammals breeding cycle comes once a month.
Pelagic fishes is a seasonal breeder.
So, the correct answer is option A.

In first year, biennial plants are only

  1. Reproductive

  2. Vegetative

  3. Both A and B

  4. None of the above


Correct Option: B
Explanation:

Biennial are plants whose entire life cycle occurs within two years. In the first year, these plants are only vegetative, meaning that they don't produce reproductive structures. Rather, these plants will grow roots below ground and a small rosette of leaves near the surface

Plants which flower only once are

  1. Pericarpic

  2. Monocarpic

  3. Polycarpic

  4. Cleistocarpic


Correct Option: B
Explanation:

Monocarpic plants flower only once in their lifetime and die immediately after the seeds are set. Also known as hapaxanth and semelparous these plants may take a long time to flower and set seeds.Example of this type of plants is Agave americana, which takes many years to flower once at times more than 50 years. 

So, the correct answer is 'Monocarpic'

A plant lives for less than one year is called

  1. Annual

  2. Biennial

  3. Semi-annual

  4. Perennial


Correct Option: A
Explanation:

A plant which can be grown only once in a year is an annual plant. A plant lives for less than one year is also called an annual plant because it cannot be grown again to complete two lifetimes in just one year.

So, the correct answer is "annual'.

Identify a monocarpic plant from the following

  1. Cuscuta

  2. Agave

  3. Mangifera

  4. Dalbergia


Correct Option: B
Explanation:

A. Cuscuta is a parasitic plant with smallest flowers many times. It blooms many times. so it is a polycarpic plant  

B. Agave americana is a monocarpic plant because it flowers only once in its lifetime of 10 years and dies.
C. Mangifera indica is also a polycarpic plant as it flowers every year during its season.
D. Dalbergia plant flowers more than once in its lifetime.
So, the correct option is B

Grasses, non flowering plants, shrubs and trees are examples of

  1. Climax Community

  2. Perennial Plants

  3. Secondary Succession

  4. Primary Succession


Correct Option: B

Some plants flower only once in their life, generally after 50 - 100 years. They produce a large number of fruits and die

  1. Strobidanthus kunthiana

  2. Bamboo

  3. Callistemon linearis

  4. Cymbopogon reptocus


Correct Option: B
Explanation:

Bamboo flower only once in their life, generally after 50 - 100 years. They produce a large number of fruits and die. They rely on seed to perpetuate themselves. 

Strobidanthus kunthiana flowers one in twelve years.
Callistemon linearis flowers normally in spring and early summer every year.
Cymbopogon reptocus is a lemon grass which rarely flowers and has no specific pattern of flowering. It is a monocot.
So, the correct answer is option B.