Tag: plant growth

Quizzes (10) Questions (270)

Questions Related to plant growth

Multiple choice senescence senescence and death plant growth plant growth and development biology

The terminal phase of ageing is called as

  1. Dedifferentiation

  2. Senescence

  3. Abscission

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

Ageing is the result of a sequential switching on and off of certain genes. Ageing results in senescence. Senescence refers to a number of controlled processes which finally culminate in the death of the plant part. The senescence is considered as the last phase in the process of ageing. 

Thus, the correct answer is option B. 

Multiple choice senescence senescence and death plant growth plant growth and development biology

During senescence of a plant.

  1. The plant displays sequential senescence of the leave

  2. Metabolites like carbohydrates, proteins etc. Are transported from young leaves to the aging leaves

  3. Metabolites like carbohydrates, proteins etc. Are transported out of the aging leaves to the young leaves

  4. Secondary plant products accumulate in the tissues are organs during aging
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice senescence senescence and death plant growth plant growth and development biology

Senescent phase of an organism's life span can be recognised by

  1. Slow metabolism

  2. Cessation of reproduction

  3. Decreased immunity

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The terminal irreversible stage of ageing is called senesence. This is the last phase of life span, that ultimately leads to death. This phase can be recognised by slow metabolism, cessation of reproduction and decreased immunity.

So, the correct answer is 'All of the above'.

Multiple choice senescence senescence and death plant growth plant growth and development biology

When a plant undergoes senescence, the nutrients may be ____________.

  1. Accumulated

  2. Bound to cell wall

  3. Translocated

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a plant part undergoes senescence, nutrient resources(minerals and carbohydrates) shift away or are translocated from the senescened part to other parts. In leaves at the time of senescene we observe loss of chlorophyll, RNA and protein, transport of nutrients and then abscission.

Multiple choice senescence senescence and death plant growth plant growth and development biology

Senescence in plants leads into .......... of cells.

  1. Increase in size

  2. Increase in number

  3. Death

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

Senescence in plants is a process of aging. During process of senescence, cells undergo differentiation. It ultimately leads into the death of cells. 

Thus, the correct answer is option C.

Multiple choice biology plant growth growth rates and conditions for growth population ecology growth and development

Fastest phase of S-shaped growth curve is

  1. Lag phase

  2. Log Phase

  3. Stationary phase

  4. Both (a) and (B).
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • S-shaped logistic growth curve includes 3 phases:
  • Lag phase - When some organisms are introduced in an area, the population growth begins slowly.
  • Log phase - The conditions are ideal and the maximum growth rate is reached.
  • Stationary phase - Growth rate begins to slow down as factors such as food, water and space become limiting.
Thus, the correct answer is 'Log phase.'

Multiple choice biology plant growth growth rates and conditions for growth population ecology growth and development

Most realistic growth curve is

  1. J-shaped

  2. Sigmoid

  3. Parabolic

  4. Both (A) & (B)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The resources for the growth of most animal population are finite and become limiting sooner or later, thus the logistic growth model is considered more realistic. The equation for model gives a sigmoid shaped graph when plotted against the N in relation to time.  The equation is :

dN/dT=rN(K-N/K) 
where, 
N is Population density at time t
r is the intrinsic rate of natural increase 
K is carrying capacity.
So, the correct answer to the question is 'Sigmoid'.

Multiple choice biology plant growth growth rates and conditions for growth population ecology growth and development

What is wrong w.r.t annual rings ?

  1. These are also called growth ring

  2. One annual ring includes one circle of spring wood and one circle of autumn wood

  3. Annual rings are distinct in plants of tropical regions

  4. they give an estimate of the age of tree
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Annual rings are distinct and prominent in plants growing in temperate regions where climatic conditions vary sharply between seasons. In tropical regions, seasonal variations are not distinct, so annual rings are typically indistinct or absent.

Multiple choice biology plant growth growth rates and conditions for growth population ecology growth and development

Most realistic growth curve 

  1. J shaped

  2. Sigmoid

  3. Parabolic

  4. Bith A and B
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The resources for the growth of most animal population are finite and become limiting sooner or later, thus the logistic growth model is considered more realistic. The equation for model gives a sigmoid shaped graph when plotted against the N in relation to time.  
The equation is :
$\dfrac{dN}{dT}$ = $rN$ $\dfrac{(K-N)}{K}$ 
where, 
N is Population density at time t
r is the intrinsic rate of natural increase 
K is carrying capacity.
So, the correct answer to the question is 'Sigmoid'.
Multiple choice biology plant growth growth rates and conditions for growth population ecology growth and development

Fastest phase of S-shaped growth curve is?

  1. Lag phase

  2. Log phase

  3. Stationary phase
  4. Both $(1)$ and $(2)$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In a typical sigmoid (S-shaped) growth curve, the growth rate is slow initially during the lag phase, accelerates exponentially to its maximum during the log (exponential) phase, and finally slows down in the stationary phase.