Tag: depletion of resources

Questions Related to depletion of resources

In a population, which is in Hardy- Weinberg equilibrium the recessive allelic frequency is $0.8$, in a population of $1300$. Find out the number of dominantindividuals in that ppulation, if the gene in reference has only two alleles   

  1. $416$

  2. $468$

  3. $640$

  4. $52$


Correct Option: B
Explanation:

Recessive freq $= q= 0.8$
$q^2 = (0.8)^2 =0.64$  
$p^2 + q^2 = 1$  
$1 - q^2 = p^2$ 
$ p^2 = 1 - 0.64= 0.36$ 
$0.36 \times 1300 = 468$

If the frequency of a dominant phenotype in a stable population is $75\%$, the frequency of recessive allele in that population would be?

  1. $0.375$

  2. $0.25$

  3. $0.75$

  4. $0.50$


Correct Option: D
Explanation:

If dominant phenotype percentage is given, we come to know about the percentage of homozygous recessive in population: which in this case is $25$%. Thus frequency of recessive allele is $0.50$.

So, the correct option is '0.50'.

The logistic population growth model, dN/dt = rN (K N/K), describes a populations growth when an upper growth is assumed. This upper limit to growth is known as the population's___  ,and as N gets larger,dN/dt________

  1. Biotic potential, increases

  2. Biotic potential, decreases

  3. Carrying capacity, increases

  4. Carrying capacity, decreases


Correct Option: D
Explanation:
  • The logistic population growth model is represented by :
dN/dt = rN (K-N/ K)
Where, N = Population density at time t
r = Intrinsic rate of natural increase
K = Carrying capacity
  • In nature, a given habitat has enough resources to support a maximum possible number, beyond which no further growth is possible. This limit is known as nature’s carrying capacity (K) for that species in that habitat.
  • As the value of N increases, the rate of growth dN/dt decreases. 
So, the correct option is 'Carrying capacity, decreases'.

In a population $100$ individual are with recessive phenetype,with allelic frequency of $0.4$, the total population sis 

  1. $625$

  2. $400$

  3. $600$

  4. $250$


Correct Option: A

Carrying capacity is

  1. The capacity of an individual to produce young ones.

  2. Availability of resources in a given habitat to support a certain number of individuals of population, beyond which no further growth is possible.

  3. Gene frequency from one generation to next.

  4. Gene frequency in same generation.


Correct Option: B
Explanation:

The carrying capacity of an organism is the maximum population size of the species that the environment can sustain indefinitely beyond which there is no further growthWhen the population reaches the carrying capacity then mortality becomes greater than natality.

Therefore, the correct answer is option B.

A pattern of idealized population growth, restricted by limiting factors is shown by

  1. Logistic growth model

  2. Carrying capacity model

  3. Dispersion model

  4. Habitat cap model

  5. Exponential growth model


Correct Option: A
Explanation:

Population growth rate measures the number of individuals in a population (N) over time (t). When the conditions are ideal, the type of growth is known as exponential form of growth which is expressed by the equation, (dN)/(dt)= rN. When the limiting factors is restricted, the growth pattern is known as logistic growth model. This model is described by the differential equation (dN)/(dt)= rN(K-N)/K, where K is the carrying capacity and r is the maximum per capita growth. 

Therefore, the correct answer is option A.

A logistic growth curve depicting a population that is limited
by a definite carrying capacity is shaped like the letter

  1. J

  2. L

  3. M

  4. S


Correct Option: D
Explanation:

A logistic growth curve that is limited by a definite carrying capacity is shaped like the letter 'S' or a sigmoid curve, which is differentiated into three parts the Lag phase, the Log phase or the exponential growth phase and the stationary or plateau phase. At this phase the amount of resources cannot support the growing population, due to which the number of members in the population is prevented from increasing

So, the correct answer is 'S'

dN/dt is 

  1. Rate of births

  2. Rate of deaths

  3. Change in population size

  4. Carrying capacity


Correct Option: C
Explanation:

The rate of change in a population can be defined as the ratio of total change in population and time taken for that change. Change in population size can be defined as difference in population size at the end and between the beginning of a particular time period

So, the correct answer is 'Change in population size'

In ecology, N/S represents ____________.

  1. Population density

  2. Rate of growth

  3. Rate of deaths

  4. Rate of births


Correct Option: A
   Column I    Column II
 a  Pacific Salmon fish   Verhulst Pearl logistic growth
 b  $N _t = N _0e^{rt}$  q  Breads only once in life time
 c  Oyster  r  Exponentoal growth
 d  $dN /dt=rN$$\left(\dfrac{K-N}{K}\right)$  s  Large number of small sozed o

Match the columns and find the correct options 



  1. a - s , b - r , c - p , d - q

  2. a - r , b - s , c - p , d - q

  3. a - r , b - p , c - s, d - q

  4. a - q , b - r , c - s , d - p

  5. a - q , b - s , c - r , d - p


Correct Option: D
Explanation:

a) Pacific salmon Fish of the genus Oncorhynchus is an individual that reproduces only once in its lifetime

b) Exponential growth is the rate of change at an unit time. It is denoted by $N _t$ = $N _0$ e^rt
c) Oyster reproduction produces a large number of small sized offsprings.
d) $ dN/dt = rN ((K-N)/K)$ is the formula for verhulst pearl logistic growth.