Tag: impact of depletion of natural resources

Questions Related to impact of depletion of natural resources

Sigmoid growth curve occurs where growth pattern is 

  1. Logistic

  2. Exponential

  3. Accretionary

  4. Geometric


Correct Option: A
Explanation:
Logistic growth model:- Sigmoid growth curve occurs where growth pattern is logistic. Unconstrained natural growth is exponential growth. A biological population with food, space to grow, and no threat from predators, tends to grow at rate proportional to population.
$\dfrac{dP}{dt}=rp$
where p$=$population function of time t
r$=$ proportionality constant.

In the equation , $\dfrac{dN}{dt}=rN(\dfrac{K-N}{K})$ , r stands for 

  1. Intrinsic rate of natural increase

  2. Death rate

  3. Population density at time t

  4. Carrying capacity

  5. The base of natural logarithms


Correct Option: A
Explanation:
The population growth rate is measured in number of individuals in a population (N) over time (t). The term for population growth rate is written as (dN/dt). The d just means change. K represents the carrying capacity, and r is the maximum per capita growth rate for a population. Per capita means per individual, and the per capita growth rate involves the number of births and deaths in a population. The logistic growth equation assumes that K and r do not change over time in a population.

So, the correct answer is 'A'.

Asymptote in a logistic growth curve is obtained when:

  1. $K=N$

  2. $K>N$

  3. $K

  4. The value of r approaches zero


Correct Option: A

Choose the incorrect one.

  1. In logistic growth equation when N $<$ K then r $> 0$

  2. In logistic growth equation when N$=$K then r$=$constant

  3. In logistic growth equation N $>$ K then r $< 0$

  4. In logistic growth equation N $>$ K then r $> 0$


Correct Option: A
Explanation:

Answer is A. 
If N is very small compared to K, then the population growth rate will be a small positive number. This means the population is slowly getting larger because there are a few more births than deaths

The concept that 'population tends to increase geometrically while food supply increases arithmetically was put forward by

  1. Adam Smith

  2. Charles Darwin

  3. Thomas Malthus

  4. Stuart Mill


Correct Option: C
Explanation:

The concept that 'population tends to increase geometrically while food supply increases arithmetically were put forward by Thomas Malthus. In his theory of natural selection, Charles Darwin was greatly influenced by the English clergyman Thomas Malthus. Malthus published a book in 17981798 stating that populations with unlimited natural resources grow very rapidly, after which population growth decreases as resources become depleted. This accelerating pattern of increasing population size is called exponential growth.

So, the correct answer is 'Thomas Malthus'.

A rancher moved his herd of cattle to a different pasture. Identify the correct statement which indicates that the carrying capacity of that pasture was exceeded, as per the given example.

  1. The herd increased in size.

  2. The pasture became overgrazed and barren.

  3. The pasture had more grasses.

  4. The cows gained weight.

  5. The cows had more calves.


Correct Option: B
Explanation:

Carrying capacity is the maximum size of the population of a species that a certain environment can support for an extended period of time. Once population overshoots the carrying capacity, it starts decreasing as at this point, the different environmental resistances start operating and population dies because of the struggle for existence. Among the given options, option B shows that carrying capacity of pasture was exceeded turning it into the barren land. The increase in grasses or weight gain of cow suggests growth of grassland.

Therefore, the correct answer is option B.

Sigmoid /logistic growth curve is represented by

  1. dN/dt=rN

  2. dN/dt=rN(1-N/K)

  3. $N _t=N _0+B+I-D-E$

  4. dN/dt=1-N/K


Correct Option: B