Tag: growth and development

Questions Related to growth and development

Fastest phase of S-shaped growth curve is

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

  1. Lag phase

  2. Log Phase

  3. Stationary phase

  4. Both (a) and (B).

Show answer
Correct Option: B
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.'

Most realistic growth curve is

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

  1. J-shaped

  2. Sigmoid

  3. Parabolic

  4. Both (A) & (B)

Show answer
Correct Option: B
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'.

What is wrong w.r.t annual rings ?

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

  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

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Correct Option: A

Most realistic growth curve 

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

  1. J shaped

  2. Sigmoid

  3. Parabolic

  4. Bith A and B

Show answer
Correct Option: B
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'.

Fastest phase of S-shaped growth curve is?

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

  1. Lag phase

  2. Log phase

  3. Stationary phase

  4. Both $(1)$ and $(2)$

Show answer
Correct Option: A

Maximum cytoplasmic growth occurs in?

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

  1. $G _1$-phase

  2. S-phase

  3. $G _2$-phase

  4. M-phase

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Correct Option: A
Explanation:

$G _1-$ phase is the period when the cell grows and carries out normal metabolism. 

In growth curve, maximum growth occurs during

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

  1. Lag phase

  2. Senescent phase

  3. Decline phase

  4. Exponential phase

Show answer
Correct Option: D
Explanation:
Bacterial growth is divided into four phases, namely lag phase, exponential phase, stationary phase and decline phase. In lag phase, there is very little or no bacterial growth. In this phase, bacteria are adjusting to the environment and synthesizing biochemicals and nutrients. In log phase, the number of bacterial cells doubles at an exponential rate. The maximum growth phase is the exponential phase. In stationary phase, the rate of cell death is equal to the rate of cell division. In decline phase, there is the decrease in the bacterial population due to lack of nutrients and high toxin concentration.
Thus, the correct answer is option D.

Ectomycorrhiza is an association of ________.

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

  1. Bacterial and plant roots

  2. Cyanobacterial and plant root

  3. Fungi and plant roots

  4. Bacteria and fungi

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Correct Option: A

The growth curve of meristematic cells at growing tip of a plant and an embryo will be?

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

  1. Linear and Y-shaped respectively

  2. J-shaped and Y-shaped respectively

  3. Y-shaped and J-shaped respectively

  4. Linear and J-shaped respectively

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Correct Option: A

Process, container is being emptied into collection vehicles at point of collection is known as:

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

  1. Hauled Container System

  2. Stationary Container System

  3. Collection System

  4. Pulverization

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Correct Option: B