CBSE Questions for Class 12 Medical Biology Organisms And Population Quiz 11 - MCQExams.com

Which of the following factors has a negative effect on the population growth rate?
  • Emigration
  • Immigration
  • Natality
  • Fecundity

The given graph shows how much nitrate $$ \left( { NO }_{ \overline { 3 }  } \right)  $$ is exported from the continent towards the ocean by 16 major rivers in the world compared to the density of human populations living along those drainage basins (i.e., along these rivers). What interpretation can be drawn from this graph?
931818_1cbb1c30ab32436db40fdb69843dabaf.png
  • Nitrate exported through rivers from heavily populated cities can cause eutrophication and toxic algal bloom in marine coastal regions.
  • Small drainage basins export more $$ { NO }_{ 3 }^{-} $$.
  • Drainage basins with higher population densities export lesser $$ { NO }_{ 3 }^{-} $$.
  • Both (a) and (c)
For which of the following cases, population density can be easily determined by utulising non-biological parameter?
  • Fish density
  • Density of Bactria in culture plate
  • Siberian cranes at Bharatpur wetlands
  • Tiger census
Which of the following is not an example of using relative density to measure population density in a certain area?
  • Counting pug marks of tigers to find population density of tigers a forest
  • Counting the number of fishes caught in a trap to find population density of fishes in a lake
  • Measuring biomass of bacterial culture to find out population density of bacteria in a petri dish
  • Measuring biomass of phytoplanktons in 1 cc water to find out population density of phytoplanktons in a lake
The density of a population in a given habitat during a given period, fluctuates due to changes in certain basic process On this basis, fill up boxes A and B the given flow chart with correct option. 
931709_9e34e7024c0d4095867e5acd066d94c2.jpg
  • A - Nasality, B - Mortality
  • A - immigration, B - Emigration
  • A - Nasality, B - immigration
  • both (a) and (b)
Which of the following is not a factor that would limit the growth of a population? 
  • Food shortage
  • Immigratin
  • Disease
  • Famine
Total number of individuals of a species per unit area and per unit time is called 
  • Population size
  • Population density
  • Demography
  • Population dynamics
A population with a larger proportion of older individuals than younger ones will likely to 
  • grow larger and then decline
  • continue to grow larger indefinitely
  • decline
  • not experience a change in population size.
Which of the following statements is/are correct?
  • Geometric growth produces J-shaped population growth curve.
  • Logistic occurs when resources are limiting.
  • Equation for exponential growth is $$N_t = N_0^{rt}$$.
  • All of these. 
Which of the following equation correct represents the exponential population growth curve?
  • dN/dt = rN
  • dN/dt = rN $$(\dfrac{K-N}{K})$$
  • $$N_t = N_0e^rt $$
  • Both A and C
In N = population density at time t, then population density at time +1 can be written as 
$$N_t+1 = N_1 + [(A +B) - (C + D)]$$
Select the correct option for A, B, C and D in the above equation. 
  • A can be mortality and B can be natality
  • B can be immigration and C can be natality
  • C can be mortality and D can be immigration
  • A can be natality and D can be emigration
Which of the following statement is/are incorrect?
  • A population has certain attributes which an individual does not have
  • Tiger census in our National parks and tiger reserves is often based on pug marks
  • If a new habitat is being colonized birth rate may contribute more significantly to population growth
  • Both (A) and (B)
The population growth is generally described by the following equation:
$$\dfrac{dN}{dt} = rN \dfrac({K-N}{K})$$
What does'r' represent in the given equation ___________________.
  • Population density at time 't'
  • Intrinsic rate of natural increase
  • Carrying capacity
  • The base of natural logarithm
In a population per capital birth rate is 0.15 and per capital death rate is 0.08 during a unit time period. What is the value of r (intrinsic rate of natural increase ) for the given population?
  • 0.23
  • 0.07
  • 0.05
  • 0.25
Study the population growth curves (A and B) in the given graph and select the incorrect option
932059_6bb9773d501f4eccb0a8c74e9471efb9.jpg
  • Curve 'A' shows exponential growth, represented by equation $$\dfrac{dN}{dr} = rN$$
  • Curve 'B' shows logistic growth, represented by equation

    $$\dfrac{dN}{dr} = rN(\dfrac{K-N}{K})$$
  • Exponential growth curve is considered as more realistic than the logistic growth curve
  • Curve 'A' can also be represented by equation $$N_t = N_0e^rt$$
The maximum possible number of individuals that a habitat can support is called its _________________.
  • fecundity
  • surviving ability
  • carrying capacity
  • biotin potential
Exponential growth is observed in a population when ____________________.
  • resources in the habitat are unlimited
  • each special has the ability to relies its full innate potential
  • limited resources are available
  • mortality is more than natality
Which of the following factors influence population density under normal conditions?
  • Deaths
  • Immigration
  • Emigration
  • Both (A) and (B)
Read the following statement and select the correct option :
Statement 1 Brood parasitism in birds is an examples of parasitism in which the parasitic bird lays its eggs in the nest of its host and the host incubates them 
Statement 2 During the course of evolution, the eggs of the parasite bird have evolved to resemble the hos's eggs in size and color to reduce the chances of the host bird detecting the feign eggs and removing them from the nest.
  • Both statement 1 and 2 are correct
  • statement 1 is correct but statement 2 is incorrect
  • statement 1 is incorrect but statement 2 is correct
  • both statement 1 and 2 are incorrect
Crowbrds lay their eggs in the nests of smaller birds. The fast-developing cowbird chicks hatch first, then push the other nest as they hatch. The cowbird classified as a
  • Pathogen
  • Parasite
  • Mutualist
  • Commensal
To determine the effect of intra-specific competition on the growth of saplings of Eucalyptus dives, an experiment was designed in which two set of pots were used. In the first set only 1 sapling was planted per pot. and in the other set 16 sapling were planted per pot. To check for the effect of intra- specific competition  of resources, a decreasing amount of water was added to each set, The results have been graphicallly indicated below. Which of the following conclusions can be best drawn from the study? 
932801_16ba3b8c5db84f70b5b89e567080e9a7.png
  • More resources are allocated to the rot during water conditions.
  • Competition for water among individuals of a population causes more root growth as compared to individuals who are growing alone
  • Lesser leaves are formed under low water conditions.
  • Rot growth is higher in individual grown singly as compared to individuals n populations
HOTS
Two insect species were used in a laboratory experiment. For the treatment, both species were grown by themselves on a suitable food source. For the second treatment, the two species were grown together on the same type and amount of food as in the first treatment. The given figure show the result at the end of the experiment. Based on these results the two species should be classified as 
932778_791a3672ab004f9ba8e7e5abc2dea1a2.jpg
  • Competitors
  • Mutualists
  • Predators or pathogens
  • Commensalists
Species interaction with negative influence on both is referred to as 
  • Amensalism
  • Mutualism
  • Commencialism
  • Competition
The plant-animals interactions often involve co-evolution of the muralists so that _______________________________.
  • the mutually beneficial system could safeguarded against cheaters
  • a given plant species can be pollinated only by its partner animal species and no other species
  • The animal utilities plant not only for ovipositioon but also to pollinate the plant
  • all of these
A population has more young individuals compared too the older individuals. What would be the status of the population after some years?
  • It will decline
  • It will stabilize
  • It will increase
  • It will first decline and then stabilize
An interaction between two individuals where one is benefited while the other is neither benefited nor harmed is called as 
  • Predation
  • Symbiosis
  • Amensallism
  • Commensalism
The interdependent evolution of flowering plants and pollinating insects together is known as
  • Mutualism
  • Coevolution
  • Commercialism
  • Cooperation
Which of the following would necessarily decrease the density of a population in a given habitat?
  • Natality > mortality
  • Immigration > emigration
  • Mortality and emigration
  • Natality and immigration
Exponential growth occurs in
  • Yeast
  • Asexual reproduction
  • Bacteria
  • All of these
Ammensalism is an association between two species where 
  • one species is harmed and other is benefited
  • one species is harmed and other is unaffected
  • one species is benefited and other is unaffected
  • booth the species are harmed
If in a population, natality is balanced by mortality then there will be.
  • Decrease in population growth
  • Zero population growth
  • Increase in population growth
  • Over population
During population growth curve, which phase shows maximum growth?
  • Positive acceleration phase
  • Positive phase
  • Negative acceleration phase
  • Logarithmic phase
If 8 individuals in a laboratory population of 80 fruitflies died in a week, then what would be the death rate for the population for that said period?
  • 8%
  • 10%
  • 1%
  • 80%
Multiple Choice Questions.
Natality is characteristic of a population which means
  • the total number of individuals present per unit area at a given time
  • the increase in number of individuals in a population under given environmental conditions
  • loss of individuals due to death in a population under given environmental conditions
  • the movement of individuals into and out of population
  • each population has three different age groups.
Cuscuta is an example of
  • Endoparasitism
  • Predation
  • Ectoparasitism
  • Brood parasitism.
Multiple Choice Questions.
A sedentary sea anemone gets attached to tho shell lining of hermit crab. The association is
  • Amensalism
  • Ectoparasitism
  • Symbiosis
  • Commensalism.
Competition results in
  • Extinction
  • Mutation
  • Larger number of niches
  • Symbiosis.
Multiple Choice Questions.
The formula for exponential growth is
  • dt/dN
  • dN/rN = dt
  • rN/dN = dt
  • dN/dt = rN
Two species can be said to be reproductively isolated if they are
  • Infertile
  • Not infertile
  • Not growing together in a common habitat
  • Growing together in a common habitat
More than ........... $$\%$$ of the world population live in arid or semiarid regions.
  • $$40$$
  • $$50$$
  • $$60$$
  • $$80$$
Rainforest forms the largest habitat on the planet.
  • True
  • False
Which of the following represents largest man made ecosystem?
  • Zoo
  • Garden
  • Aquarium
  • Agroecosystem
Which of the following which is the smallest parasite?
  • Lemna
  • Arceuthobium
  • Wolffia
  • Spirodella
Association of sea anemone and hermit crab is an example of?
  • Parasitism
  • Predation
  • Commensalism
  • Mutualism
In both commensalism and amensalism only one species benefits and the interaction is detrimental to the other species
  • True
  • False
Exaggerated dread of a disease is known as
  • Haemotophobia
  • Algophobia
  • Pathophobia
  • Myophobia
A close mutualistic association between flower and pollinating agent is found in 
  • Yucca and Yucca moth (pronuba)
  • Fig and Blastophaga wasp
  • Ophrys and male colpa wasp
  • all of the above
Within the exponential phase of growth, if the initial surface area and growth rate of leaf is
$${ 10mm }^{ 2 }$$ and $$0.015 mm^2$$ hour respectively,the area of the leaf after 4 days would range from
  • $$10$$ to $$12mm^2$$
  • $$20$$ to $$24mm^2$$
  • $$30$$ to $$36mm^2$$
  • $$40$$ to $$48mm^2$$
What kind of interaction, species A and B are showing:-
1149789_ebebe613e0fa492385edf3a7a117cf45.PNG
  • Mutualism
  • Proto-coperation
  • Parasitism
  • Predation
Which kind of interaction, species A is showing with species B, C and D:-
1149752_822fdb7e02614186a0743774a087a06b.PNG
  • Mutualism
  • Proto-coperation
  • Parasitism
  • Commensalism
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