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Organisms and Populations · Question 41

NEET 2016 (Phase 1)MCQMedium📈 Topic in 75% papers+4−1
1

When does the growth rate of a population following the logistic model equal zero? The logistic model is given as dN/dt = rN(1-N/K)

  1. When death rate is greater than birth rate.
  2. When N/K equals zero.
  3. When N/K is exactly one.
  4. When N nears the carrying capacity of the habitat.

Answer

(3) When N/K is exactly one.

Solution

As per NCERT, logistic growth: dNdt = rN ( K-NK )

⇒ dNdt = 0 when 1 - NK = 0

∴ NK = 1, i.e. N = K exactly (population at carrying capacity).

∵ When N only nears K, growth rate is small but not zero; when N/K = 0, there is no population at all.

Answer: (3)

NEET 2016 (Phase 1)

Keep practising — Organisms and Populations

2

Gause's principle of competitive exclusion states that -

  1. Larger organisms exclude smaller ones through competition
  2. More abundant species will exclude the less abundant species through competition
  3. Competition for the same resources excludes species having different food preferences
  4. No two species can occupy the same niche indefinitely for the same limiting resources
NEET 2016 (Phase 1)
3

Which of the following is correct for r-selected species ?

  1. Small number of progeny with small size
  2. Small number of progeny with large size
  3. Large number of progeny with small size
  4. Large number of progeny with large size
NEET 2016 (Phase 2)
4

If '+' sign is assigned to beneficial interaction, '–' sign to detrimental and '0' sign to neutral interaction, then the population interaction represented by '+' '–' refers to

  1. parasitism
  2. commensalism
  3. mutualism
  4. amensalism
NEET 2016 (Phase 2)
5

The principle of competitive exclusion was stated by

  1. MacArthur
  2. G. F. Gause
  3. Verhulst & Pearl
  4. C. Darwin
NEET 2016 (Phase 2)
6

In which of the following interactions both partners are adversely affected?

  1. Competition
  2. Predation
  3. Mutualism
  4. Parasitism
AIPMT 2015
7

The following graph depicts changes in two populations (A and B) of herbivores in a grassy field. A possible reason for these changes is that: [figure]

  1. Population B competed more successfully for food than population A
  2. Population A consumed the members of population B
  3. Both plant populations in this habitat decreased
  4. Population A produced more offspring than population B
AIPMT 2015 (Cancelled)
8

Most animals are tree dwellers in a:

  1. temperate deciduous forest
  2. tropical rain forest
  3. coniferous forest
  4. thorn woodland
AIPMT 2015 (Cancelled)
9

Just as a person moving from Delhi to Shimla to escape the heat for the duration of hot summer, thousands of migratory birds from Siberia and other extremely cold northern regions move to:

  1. Keoladeo National Park
  2. Meghalaya
  3. Corbett National Park
  4. Western Ghat
AIPMT 2014
10

A sedentary sea anemone gets attached to the shell lining of hermit crab. The association is :

  1. Commensalism
  2. Amensalism
  3. Ectoparasitism
  4. Symbiosis
NEET 2013
11

A biologist studied the population of rats in a barn. He found that the average natality was 250, average mortality 240, immigration 20 and emigration 30. The net increase in population is :

  1. 15
  2. 05
  3. 10
  4. zero
NEET 2013

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All NEET Botany chapters
Class 11The Living WorldBiological ClassificationPlant KingdomMorphology of Flowering PlantsAnatomy of Flowering PlantsCell: The Unit of LifeCell Cycle and Cell DivisionTransport in PlantsMineral NutritionPhotosynthesis in Higher PlantsRespiration in PlantsPlant Growth and Development
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